Merge pull request #901 from tannewt/pulseio_too_fast

Prevent freezing USB during high frequency PulseIn.

31 files changed, 608 insertions, 25 deletions

diff --git a/ports/atmel-samd/background.c b/ports/atmel-samd/background.c
index 92648f42e..4cba7a110 100644
--- a/ports/atmel-samd/background.c
+++ b/ports/atmel-samd/background.c
@@ -26,11 +26,19 @@
 #include "background.h"
 
 #include "audio_dma.h"
+#include "tick.h"
 #include "usb.h"
 #include "usb_mass_storage.h"
 
+volatile uint64_t last_finished_tick = 0;
+
 void run_background_tasks(void) {
     audio_dma_background();
     usb_msc_background();
     usb_cdc_background();
+    last_finished_tick = ticks_ms;
+}
+
+bool background_tasks_ok(void) {
+    return ticks_ms - last_finished_tick < 1000;
 }
diff --git a/ports/atmel-samd/background.h b/ports/atmel-samd/background.h
index f7fb10a1f..e841049a4 100644
--- a/ports/atmel-samd/background.h
+++ b/ports/atmel-samd/background.h
@@ -27,6 +27,9 @@
 #ifndef MICROPY_INCLUDED_ATMEL_SAMD_BACKGROUND_H
 #define MICROPY_INCLUDED_ATMEL_SAMD_BACKGROUND_H
 
+#include <stdbool.h>
+
 void run_background_tasks(void);
+bool background_tasks_ok(void);
 
 #endif  // MICROPY_INCLUDED_ATMEL_SAMD_BACKGROUND_H
diff --git a/ports/atmel-samd/bindings/samd/Clock.c b/ports/atmel-samd/bindings/samd/Clock.c
index 3c87177a4..e09cc0bd8 100644
--- a/ports/atmel-samd/bindings/samd/Clock.c
+++ b/ports/atmel-samd/bindings/samd/Clock.c
@@ -47,15 +47,7 @@
 STATIC void samd_clock_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
     samd_clock_obj_t *self = MP_OBJ_TO_PTR(self_in);
 
-    mp_printf(print, "%q.%q.%s(", MP_QSTR_samd, MP_QSTR_clock, self->name);
-    if (clock_get_enabled(self->type, self->index)) {
-        mp_printf(print, "frequency=%u", clock_get_frequency(self->type, self->index));
-        uint32_t calibration = clock_get_calibration(self->type, self->index);
-        if (calibration) {
-            mp_printf(print, ", calibration=%u", calibration);
-        }
-    }
-    mp_printf(print, ")");
+    mp_printf(print, "%q.%q.%q", MP_QSTR_samd, MP_QSTR_clock, self->name);
 }
 
 //|     .. attribute:: enabled
diff --git a/ports/atmel-samd/bindings/samd/Clock.h b/ports/atmel-samd/bindings/samd/Clock.h
index 0d13ae253..ccc8f10d1 100644
--- a/ports/atmel-samd/bindings/samd/Clock.h
+++ b/ports/atmel-samd/bindings/samd/Clock.h
@@ -31,7 +31,7 @@
 
 typedef struct {
     mp_obj_base_t base;
-    const char *name;
+    qstr name;
     uint8_t type;
     uint8_t index;
 } samd_clock_obj_t;
@@ -39,7 +39,7 @@ typedef struct {
 #define CLOCK(_name, _type, _index) \
 const samd_clock_obj_t clock_ ## _name = { \
     { &samd_clock_type }, \
-    .name = #_name, \
+    .name = MP_QSTR_ ## _name, \
     .type = _type, \
     .index = _index, \
 }
@@ -47,7 +47,7 @@ const samd_clock_obj_t clock_ ## _name = { \
 #define CLOCK_SOURCE(_name) \
 const samd_clock_obj_t clock_ ## _name = { \
     { &samd_clock_type }, \
-    .name = #_name, \
+    .name = MP_QSTR_ ## _name, \
     .type = 0, \
     .index = GCLK_SOURCE_ ## _name, \
 }
@@ -55,7 +55,7 @@ const samd_clock_obj_t clock_ ## _name = { \
 #define CLOCK_GCLK(_name) \
 const samd_clock_obj_t clock_ ## _name = { \
     { &samd_clock_type }, \
-    .name = #_name, \
+    .name = MP_QSTR_ ## _name, \
     .type = 1, \
     .index = _name ## _GCLK_ID, \
 }
@@ -63,7 +63,7 @@ const samd_clock_obj_t clock_ ## _name = { \
 #define CLOCK_GCLK_(_name, _extra) \
 const samd_clock_obj_t clock_ ## _name ## _ ## _extra = { \
     { &samd_clock_type }, \
-    .name = #_name "_" #_extra, \
+    .name = MP_QSTR_ ## _name ## _ ## _extra, \
     .type = 1, \
     .index = _name ## _GCLK_ID_ ## _extra, \
 }
diff --git a/ports/atmel-samd/boards/arduino_zero/mpconfigboard.h b/ports/atmel-samd/boards/arduino_zero/mpconfigboard.h
index a32f128f5..1382d4736 100644
--- a/ports/atmel-samd/boards/arduino_zero/mpconfigboard.h
+++ b/ports/atmel-samd/boards/arduino_zero/mpconfigboard.h
@@ -24,3 +24,7 @@
 
 #define DEFAULT_UART_BUS_RX (&pin_PA11)
 #define DEFAULT_UART_BUS_TX (&pin_PA10)
+
+// USB is always used internally so skip the pin objects for it.
+#define IGNORE_PIN_PA24     1
+#define IGNORE_PIN_PA25     1
diff --git a/ports/atmel-samd/boards/circuitplayground_express/mpconfigboard.h b/ports/atmel-samd/boards/circuitplayground_express/mpconfigboard.h
index 3d97e2cb1..5077840cb 100644
--- a/ports/atmel-samd/boards/circuitplayground_express/mpconfigboard.h
+++ b/ports/atmel-samd/boards/circuitplayground_express/mpconfigboard.h
@@ -68,3 +68,7 @@
 
 #define DEFAULT_UART_BUS_RX (&pin_PB09)
 #define DEFAULT_UART_BUS_TX (&pin_PB08)
+
+// USB is always used internally so skip the pin objects for it.
+#define IGNORE_PIN_PA24     1
+#define IGNORE_PIN_PA25     1
diff --git a/ports/atmel-samd/boards/circuitplayground_express_crickit/mpconfigboard.h b/ports/atmel-samd/boards/circuitplayground_express_crickit/mpconfigboard.h
index 83cc19d9f..638a6646c 100644
--- a/ports/atmel-samd/boards/circuitplayground_express_crickit/mpconfigboard.h
+++ b/ports/atmel-samd/boards/circuitplayground_express_crickit/mpconfigboard.h
@@ -71,3 +71,7 @@
 
 #define DEFAULT_UART_BUS_RX (&pin_PB09)
 #define DEFAULT_UART_BUS_TX (&pin_PB08)
+
+// USB is always used internally so skip the pin objects for it.
+#define IGNORE_PIN_PA24     1
+#define IGNORE_PIN_PA25     1
diff --git a/ports/atmel-samd/boards/feather_m0_adalogger/mpconfigboard.h b/ports/atmel-samd/boards/feather_m0_adalogger/mpconfigboard.h
index 94caa7d04..c8b5c56ee 100644
--- a/ports/atmel-samd/boards/feather_m0_adalogger/mpconfigboard.h
+++ b/ports/atmel-samd/boards/feather_m0_adalogger/mpconfigboard.h
@@ -22,3 +22,7 @@
 
 #define DEFAULT_UART_BUS_RX (&pin_PA11)
 #define DEFAULT_UART_BUS_TX (&pin_PA10)
+
+// USB is always used internally so skip the pin objects for it.
+#define IGNORE_PIN_PA24     1
+#define IGNORE_PIN_PA25     1
diff --git a/ports/atmel-samd/boards/feather_m0_basic/mpconfigboard.h b/ports/atmel-samd/boards/feather_m0_basic/mpconfigboard.h
index 34de8e166..dcac9749d 100644
--- a/ports/atmel-samd/boards/feather_m0_basic/mpconfigboard.h
+++ b/ports/atmel-samd/boards/feather_m0_basic/mpconfigboard.h
@@ -23,3 +23,7 @@
 
 #define DEFAULT_UART_BUS_RX (&pin_PA11)
 #define DEFAULT_UART_BUS_TX (&pin_PA10)
+
+// USB is always used internally so skip the pin objects for it.
+#define IGNORE_PIN_PA24     1
+#define IGNORE_PIN_PA25     1
diff --git a/ports/atmel-samd/boards/feather_m0_express/mpconfigboard.h b/ports/atmel-samd/boards/feather_m0_express/mpconfigboard.h
index bfa8c642a..108d67d9f 100644
--- a/ports/atmel-samd/boards/feather_m0_express/mpconfigboard.h
+++ b/ports/atmel-samd/boards/feather_m0_express/mpconfigboard.h
@@ -58,3 +58,7 @@
 
 #define DEFAULT_UART_BUS_RX (&pin_PA11)
 #define DEFAULT_UART_BUS_TX (&pin_PA10)
+
+// USB is always used internally so skip the pin objects for it.
+#define IGNORE_PIN_PA24     1
+#define IGNORE_PIN_PA25     1
diff --git a/ports/atmel-samd/boards/feather_m0_rfm69/mpconfigboard.h b/ports/atmel-samd/boards/feather_m0_rfm69/mpconfigboard.h
index 4f4ea2ffe..4a530ed29 100644
--- a/ports/atmel-samd/boards/feather_m0_rfm69/mpconfigboard.h
+++ b/ports/atmel-samd/boards/feather_m0_rfm69/mpconfigboard.h
@@ -23,3 +23,7 @@
 
 #define DEFAULT_UART_BUS_RX (&pin_PA11)
 #define DEFAULT_UART_BUS_TX (&pin_PA10)
+
+// USB is always used internally so skip the pin objects for it.
+#define IGNORE_PIN_PA24     1
+#define IGNORE_PIN_PA25     1
diff --git a/ports/atmel-samd/boards/feather_m0_rfm9x/mpconfigboard.h b/ports/atmel-samd/boards/feather_m0_rfm9x/mpconfigboard.h
index a9d586c2e..3a6f28c12 100644
--- a/ports/atmel-samd/boards/feather_m0_rfm9x/mpconfigboard.h
+++ b/ports/atmel-samd/boards/feather_m0_rfm9x/mpconfigboard.h
@@ -23,3 +23,7 @@
 
 #define DEFAULT_UART_BUS_RX (&pin_PA11)
 #define DEFAULT_UART_BUS_TX (&pin_PA10)
+
+// USB is always used internally so skip the pin objects for it.
+#define IGNORE_PIN_PA24     1
+#define IGNORE_PIN_PA25     1
diff --git a/ports/atmel-samd/boards/feather_m0_supersized/mpconfigboard.h b/ports/atmel-samd/boards/feather_m0_supersized/mpconfigboard.h
index c8118e48b..a7a2d7de0 100644
--- a/ports/atmel-samd/boards/feather_m0_supersized/mpconfigboard.h
+++ b/ports/atmel-samd/boards/feather_m0_supersized/mpconfigboard.h
@@ -57,3 +57,7 @@
 
 #define DEFAULT_UART_BUS_RX (&pin_PA11)
 #define DEFAULT_UART_BUS_TX (&pin_PA10)
+
+// USB is always used internally so skip the pin objects for it.
+#define IGNORE_PIN_PA24     1
+#define IGNORE_PIN_PA25     1
diff --git a/ports/atmel-samd/boards/feather_m4_express/mpconfigboard.h b/ports/atmel-samd/boards/feather_m4_express/mpconfigboard.h
index bb5c0ddcc..c82395baf 100644
--- a/ports/atmel-samd/boards/feather_m4_express/mpconfigboard.h
+++ b/ports/atmel-samd/boards/feather_m4_express/mpconfigboard.h
@@ -43,3 +43,7 @@
 
 #define DEFAULT_UART_BUS_RX (&pin_PB17)
 #define DEFAULT_UART_BUS_TX (&pin_PB16)
+
+// USB is always used internally so skip the pin objects for it.
+#define IGNORE_PIN_PA24     1
+#define IGNORE_PIN_PA25     1
diff --git a/ports/atmel-samd/boards/gemma_m0/mpconfigboard.h b/ports/atmel-samd/boards/gemma_m0/mpconfigboard.h
index 53e802f17..1ec217096 100644
--- a/ports/atmel-samd/boards/gemma_m0/mpconfigboard.h
+++ b/ports/atmel-samd/boards/gemma_m0/mpconfigboard.h
@@ -40,6 +40,9 @@
 #define IGNORE_PIN_PA20     1
 #define IGNORE_PIN_PA21     1
 #define IGNORE_PIN_PA22     1
+// USB is always used.
+#define IGNORE_PIN_PA24     1
+#define IGNORE_PIN_PA25     1
 #define IGNORE_PIN_PA27     1
 #define IGNORE_PIN_PA28     1
 #define IGNORE_PIN_PA30     1
diff --git a/ports/atmel-samd/boards/itsybitsy_m0_express/mpconfigboard.h b/ports/atmel-samd/boards/itsybitsy_m0_express/mpconfigboard.h
index 3adcb7f16..f56f57c46 100644
--- a/ports/atmel-samd/boards/itsybitsy_m0_express/mpconfigboard.h
+++ b/ports/atmel-samd/boards/itsybitsy_m0_express/mpconfigboard.h
@@ -56,3 +56,7 @@
 
 #define DEFAULT_UART_BUS_RX (&pin_PA11)
 #define DEFAULT_UART_BUS_TX (&pin_PA10)
+
+// USB is always used internally so skip the pin objects for it.
+#define IGNORE_PIN_PA24     1
+#define IGNORE_PIN_PA25     1
diff --git a/ports/atmel-samd/boards/itsybitsy_m4_express/mpconfigboard.h b/ports/atmel-samd/boards/itsybitsy_m4_express/mpconfigboard.h
index 116d4dac6..e47d5390d 100644
--- a/ports/atmel-samd/boards/itsybitsy_m4_express/mpconfigboard.h
+++ b/ports/atmel-samd/boards/itsybitsy_m4_express/mpconfigboard.h
@@ -41,3 +41,7 @@
 
 #define DEFAULT_UART_BUS_RX (&pin_PA16)
 #define DEFAULT_UART_BUS_TX (&pin_PA17)
+
+// USB is always used internally so skip the pin objects for it.
+#define IGNORE_PIN_PA24     1
+#define IGNORE_PIN_PA25     1
diff --git a/ports/atmel-samd/boards/metro_m0_express/mpconfigboard.h b/ports/atmel-samd/boards/metro_m0_express/mpconfigboard.h
index f798c5d36..135d6ae92 100644
--- a/ports/atmel-samd/boards/metro_m0_express/mpconfigboard.h
+++ b/ports/atmel-samd/boards/metro_m0_express/mpconfigboard.h
@@ -59,3 +59,7 @@
 
 #define DEFAULT_UART_BUS_RX (&pin_PA11)
 #define DEFAULT_UART_BUS_TX (&pin_PA10)
+
+// USB is always used internally so skip the pin objects for it.
+#define IGNORE_PIN_PA24     1
+#define IGNORE_PIN_PA25     1
diff --git a/ports/atmel-samd/boards/metro_m4_express/mpconfigboard.h b/ports/atmel-samd/boards/metro_m4_express/mpconfigboard.h
index 4d206a4c8..050f678dd 100644
--- a/ports/atmel-samd/boards/metro_m4_express/mpconfigboard.h
+++ b/ports/atmel-samd/boards/metro_m4_express/mpconfigboard.h
@@ -44,3 +44,7 @@
 
 #define DEFAULT_UART_BUS_RX (&pin_PA23)
 #define DEFAULT_UART_BUS_TX (&pin_PA22)
+
+// USB is always used internally so skip the pin objects for it.
+#define IGNORE_PIN_PA24     1
+#define IGNORE_PIN_PA25     1
diff --git a/ports/atmel-samd/boards/trinket_m0/mpconfigboard.h b/ports/atmel-samd/boards/trinket_m0/mpconfigboard.h
index d561947e3..9036f8e7b 100644
--- a/ports/atmel-samd/boards/trinket_m0/mpconfigboard.h
+++ b/ports/atmel-samd/boards/trinket_m0/mpconfigboard.h
@@ -30,6 +30,9 @@
 #define IGNORE_PIN_PA21     1
 #define IGNORE_PIN_PA22     1
 #define IGNORE_PIN_PA23     1
+// USB is always used internally so skip the pin objects for it.
+#define IGNORE_PIN_PA24     1
+#define IGNORE_PIN_PA25     1
 #define IGNORE_PIN_PA27     1
 #define IGNORE_PIN_PA28     1
 #define IGNORE_PIN_PA30     1
diff --git a/ports/atmel-samd/boards/trinket_m0_haxpress/mpconfigboard.h b/ports/atmel-samd/boards/trinket_m0_haxpress/mpconfigboard.h
index 3377d1b7e..8e3fdd7a8 100644
--- a/ports/atmel-samd/boards/trinket_m0_haxpress/mpconfigboard.h
+++ b/ports/atmel-samd/boards/trinket_m0_haxpress/mpconfigboard.h
@@ -64,3 +64,7 @@
 
 #define DEFAULT_UART_BUS_RX (&pin_PA07)
 #define DEFAULT_UART_BUS_TX (&pin_PA06)
+
+// USB is always used internally so skip the pin objects for it.
+#define IGNORE_PIN_PA24     1
+#define IGNORE_PIN_PA25     1
diff --git a/ports/atmel-samd/boards/ugame10/mpconfigboard.h b/ports/atmel-samd/boards/ugame10/mpconfigboard.h
index 4e5e88569..ed822952d 100644
--- a/ports/atmel-samd/boards/ugame10/mpconfigboard.h
+++ b/ports/atmel-samd/boards/ugame10/mpconfigboard.h
@@ -52,3 +52,7 @@
     { MP_OBJ_NEW_QSTR(MP_QSTR_audioio), (mp_obj_t)&audioio_module }, \
     { MP_OBJ_NEW_QSTR(MP_QSTR_gamepad),(mp_obj_t)&gamepad_module }, \
     { MP_OBJ_NEW_QSTR(MP_QSTR__stage), (mp_obj_t)&stage_module }
+
+// USB is always used internally so skip the pin objects for it.
+#define IGNORE_PIN_PA24     1
+#define IGNORE_PIN_PA25     1
diff --git a/ports/atmel-samd/common-hal/microcontroller/__init__.c b/ports/atmel-samd/common-hal/microcontroller/__init__.c
index c57b6939c..ad4d81ddd 100644
--- a/ports/atmel-samd/common-hal/microcontroller/__init__.c
+++ b/ports/atmel-samd/common-hal/microcontroller/__init__.c
@@ -40,18 +40,10 @@ void common_hal_mcu_delay_us(uint32_t delay) {
     mp_hal_delay_us(delay);
 }
 
-// Interrupt flags that will be saved and restored during disable/Enable
-// interrupt functions below.
-
-// ASF4's interrupt disable doesn't handle duplicate calls
-volatile uint32_t interrupt_flags;
 volatile uint32_t nesting_count = 0;
 void common_hal_mcu_disable_interrupts(void) {
-    if (nesting_count == 0) {
-        interrupt_flags = __get_PRIMASK();
-        __disable_irq();
-        __DMB();
-    }
+    __disable_irq();
+    __DMB();
     nesting_count++;
 }
 
@@ -66,7 +58,7 @@ void common_hal_mcu_enable_interrupts(void) {
         return;
     }
     __DMB();
-    __set_PRIMASK(interrupt_flags);
+    __enable_irq();
 }
 
 extern uint32_t _ezero;
diff --git a/ports/atmel-samd/common-hal/pulseio/PulseIn.c b/ports/atmel-samd/common-hal/pulseio/PulseIn.c
index 99a60a829..d16bbf9d2 100644
--- a/ports/atmel-samd/common-hal/pulseio/PulseIn.c
+++ b/ports/atmel-samd/common-hal/pulseio/PulseIn.c
@@ -31,6 +31,7 @@
 #include "atmel_start_pins.h"
 #include "hal/include/hal_gpio.h"
 
+#include "background.h"
 #include "mpconfigport.h"
 #include "py/gc.h"
 #include "py/runtime.h"
@@ -60,10 +61,16 @@ void pulsein_interrupt_handler(uint8_t channel) {
     uint32_t current_us;
     uint64_t current_ms;
     current_tick(&current_ms, &current_us);
+
     // current_tick gives us the remaining us until the next tick but we want the number since the
     // last ms.
     current_us = 1000 - current_us;
     pulseio_pulsein_obj_t* self = get_eic_channel_data(channel);
+    if (!background_tasks_ok() || self->errored_too_fast) {
+        self->errored_too_fast = true;
+        common_hal_pulseio_pulsein_pause(self);
+        return;
+    }
     if (self->first_edge) {
         self->first_edge = false;
         pulsein_set_config(self, false);
@@ -118,6 +125,7 @@ void common_hal_pulseio_pulsein_construct(pulseio_pulsein_obj_t* self,
     self->first_edge = true;
     self->last_us = 0;
     self->last_ms = 0;
+    self->errored_too_fast = false;
 
     set_eic_channel_data(pin->extint_channel, (void*) self);
 
@@ -157,6 +165,9 @@ void common_hal_pulseio_pulsein_resume(pulseio_pulsein_obj_t* self,
     // Make sure we're paused.
     common_hal_pulseio_pulsein_pause(self);
 
+    // Reset erroring
+    self->errored_too_fast = false;
+
     // Send the trigger pulse.
     if (trigger_duration > 0) {
         gpio_set_pin_pull_mode(self->pin, GPIO_PULL_OFF);
@@ -207,6 +218,11 @@ uint16_t common_hal_pulseio_pulsein_get_len(pulseio_pulsein_obj_t* self) {
     return self->len;
 }
 
+bool common_hal_pulseio_pulsein_get_paused(pulseio_pulsein_obj_t* self) {
+    uint32_t mask = 1 << self->channel;
+    return (EIC->INTENSET.reg & (mask << EIC_INTENSET_EXTINT_Pos)) == 0;
+}
+
 uint16_t common_hal_pulseio_pulsein_get_item(pulseio_pulsein_obj_t* self,
         int16_t index) {
     common_hal_mcu_disable_interrupts();
diff --git a/ports/atmel-samd/common-hal/pulseio/PulseIn.h b/ports/atmel-samd/common-hal/pulseio/PulseIn.h
index 3d79b50c3..f5326d9e5 100644
--- a/ports/atmel-samd/common-hal/pulseio/PulseIn.h
+++ b/ports/atmel-samd/common-hal/pulseio/PulseIn.h
@@ -43,6 +43,7 @@ typedef struct {
     volatile bool first_edge;
     volatile uint64_t last_ms;
     volatile uint16_t last_us;
+    volatile bool errored_too_fast;
 } pulseio_pulsein_obj_t;
 
 void pulsein_reset(void);
diff --git a/ports/atmel-samd/peripherals/samd21/clocks.c b/ports/atmel-samd/peripherals/samd21/clocks.c
index 51b7ad993..422290e8b 100644
--- a/ports/atmel-samd/peripherals/samd21/clocks.c
+++ b/ports/atmel-samd/peripherals/samd21/clocks.c
@@ -130,6 +130,9 @@ static void init_clock_source_dfll48m_xosc(void) {
                             SYSCTRL_DFLLCTRL_ENABLE;
     while (!SYSCTRL->PCLKSR.bit.DFLLRDY) {}
     while (GCLK->STATUS.bit.SYNCBUSY) {}
+
+    // Wait for the fine lock on the DFLL.
+    while (!SYSCTRL->PCLKSR.bit.DFLLLCKC || !SYSCTRL->PCLKSR.bit.DFLLLCKF) {}
 }
 
 static void init_clock_source_dfll48m_usb(void) {
diff --git a/ports/atmel-samd/tick.c b/ports/atmel-samd/tick.c
index 6cd7c7833..9753a1a0c 100644
--- a/ports/atmel-samd/tick.c
+++ b/ports/atmel-samd/tick.c
@@ -60,6 +60,22 @@ void tick_init() {
     uint32_t ticks_per_ms = common_hal_mcu_processor_get_frequency() / 1000;
     SysTick_Config(ticks_per_ms-1);
     NVIC_EnableIRQ(SysTick_IRQn);
+    // Set all peripheral interrupt priorities to the lowest priority by default.
+    for (uint16_t i = 0; i < PERIPH_COUNT_IRQn; i++) {
+        NVIC_SetPriority(i, (1UL << __NVIC_PRIO_BITS) - 1UL);
+    }
+    // Bump up the systick interrupt.
+    NVIC_SetPriority(SysTick_IRQn, 1);
+    #ifdef SAMD21
+    NVIC_SetPriority(USB_IRQn, 1);
+    #endif
+
+    #ifdef SAMD51
+    NVIC_SetPriority(USB_0_IRQn, 1);
+    NVIC_SetPriority(USB_1_IRQn, 1);
+    NVIC_SetPriority(USB_2_IRQn, 1);
+    NVIC_SetPriority(USB_3_IRQn, 1);
+    #endif
 }
 
 void tick_delay(uint32_t us) {
diff --git a/ports/nrf/common-hal/pulseio/PulseIn.c b/ports/nrf/common-hal/pulseio/PulseIn.c
index aa6bb8665..e759ac3a3 100644
--- a/ports/nrf/common-hal/pulseio/PulseIn.c
+++ b/ports/nrf/common-hal/pulseio/PulseIn.c
@@ -71,6 +71,10 @@ uint16_t common_hal_pulseio_pulsein_get_maxlen(pulseio_pulsein_obj_t* self) {
     return 0xadaf;
 }
 
+bool common_hal_pulseio_pulsein_get_paused(pulseio_pulsein_obj_t* self) {
+    return true;
+}
+
 uint16_t common_hal_pulseio_pulsein_get_len(pulseio_pulsein_obj_t* self) {
     return 0xadaf;
 }
diff --git a/shared-bindings/pulseio/PulseIn.c b/shared-bindings/pulseio/PulseIn.c
index 736441c74..862dbd99d 100644
--- a/shared-bindings/pulseio/PulseIn.c
+++ b/shared-bindings/pulseio/PulseIn.c
@@ -219,6 +219,26 @@ const mp_obj_property_t pulseio_pulsein_maxlen_obj = {
               (mp_obj_t)&mp_const_none_obj},
 };
 
+//|   .. attribute:: paused
+//|
+//|     True when pulse capture is paused as a result of :py:func:`pause` or an error during capture
+//|     such as a signal that is too fast.
+//|
+STATIC mp_obj_t pulseio_pulsein_obj_get_paused(mp_obj_t self_in) {
+    pulseio_pulsein_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    raise_error_if_deinited(common_hal_pulseio_pulsein_deinited(self));
+
+    return mp_obj_new_bool(common_hal_pulseio_pulsein_get_paused(self));
+}
+MP_DEFINE_CONST_FUN_OBJ_1(pulseio_pulsein_get_paused_obj, pulseio_pulsein_obj_get_paused);
+
+const mp_obj_property_t pulseio_pulsein_paused_obj = {
+    .base.type = &mp_type_property,
+    .proxy = {(mp_obj_t)&pulseio_pulsein_get_paused_obj,
+              (mp_obj_t)&mp_const_none_obj,
+              (mp_obj_t)&mp_const_none_obj},
+};
+
 //|   .. method:: __len__()
 //|
 //|     Returns the current pulse length
@@ -285,7 +305,10 @@ STATIC const mp_rom_map_elem_t pulseio_pulsein_locals_dict_table[] = {
     { MP_ROM_QSTR(MP_QSTR_resume), MP_ROM_PTR(&pulseio_pulsein_resume_obj) },
     { MP_ROM_QSTR(MP_QSTR_clear), MP_ROM_PTR(&pulseio_pulsein_clear_obj) },
     { MP_ROM_QSTR(MP_QSTR_popleft), MP_ROM_PTR(&pulseio_pulsein_popleft_obj) },
+
+    // Properties
     { MP_ROM_QSTR(MP_QSTR_maxlen), MP_ROM_PTR(&pulseio_pulsein_maxlen_obj) },
+    { MP_ROM_QSTR(MP_QSTR_paused), MP_ROM_PTR(&pulseio_pulsein_paused_obj) },
 };
 STATIC MP_DEFINE_CONST_DICT(pulseio_pulsein_locals_dict, pulseio_pulsein_locals_dict_table);
 
diff --git a/shared-bindings/pulseio/PulseIn.h b/shared-bindings/pulseio/PulseIn.h
index 88b6f356e..e28a3c2df 100644
--- a/shared-bindings/pulseio/PulseIn.h
+++ b/shared-bindings/pulseio/PulseIn.h
@@ -41,6 +41,7 @@ extern void common_hal_pulseio_pulsein_resume(pulseio_pulsein_obj_t* self, uint1
 extern void common_hal_pulseio_pulsein_clear(pulseio_pulsein_obj_t* self);
 extern uint16_t common_hal_pulseio_pulsein_popleft(pulseio_pulsein_obj_t* self);
 extern uint16_t common_hal_pulseio_pulsein_get_maxlen(pulseio_pulsein_obj_t* self);
+extern bool common_hal_pulseio_pulsein_get_paused(pulseio_pulsein_obj_t* self);
 extern uint16_t common_hal_pulseio_pulsein_get_len(pulseio_pulsein_obj_t* self);
 extern uint16_t common_hal_pulseio_pulsein_get_item(pulseio_pulsein_obj_t* self, int16_t index);
 
diff --git a/tools/chart_code_size.py b/tools/chart_code_size.py
new file mode 100644
index 000000000..0b55787fa
--- /dev/null
+++ b/tools/chart_code_size.py
@@ -0,0 +1,454 @@
+# This script renders a graph of the CircuitPython rom image.
+# It takes the single elf file and uses objdump to get its contents.
+
+import pygraphviz as pgv
+import click
+import sh
+
+# Replace dashes with underscores
+objdump = sh.arm_none_eabi_objdump
+
+def parse_hex(h):
+    return int("0x" + h, 0)
+
+BAD_JUMPS = ["UNPREDICTABLE", "_etext"]
+
+SPECIAL_NODE_COLORS = {
+    "main": "pink",
+    "exception_table": "green"
+}
+
+@click.command()
+@click.argument("elf_filename")
+def do_all_the_things(elf_filename):
+    symbol = None
+    last_address = 0
+    all_symbols = {}
+    symbols_by_debug_address = {}
+    symbols_by_memory_address = {}
+    symbols_by_linkage_name = {}
+    # Gather type info so we know how to treat the disassembly
+    debug_dump = objdump("--dwarf=info", elf_filename)
+    debug_dump_lines = debug_dump.stdout.decode("utf-8").split("\n")
+    symbol_stack = []
+    symbol = None
+    ignore = False
+    min_call_site_param = 0x20000000
+    for line in debug_dump_lines:
+        if not line:
+            continue
+        parts = line.split()
+        if line[1] == "<":
+            if parts[-1] == "0":
+                symbol = symbol_stack.pop()
+                continue
+            debug_type = parts[-1].strip("()")
+            ignore = False
+            # skip info about function parameters
+            if debug_type == "DW_TAG_formal_parameter":
+                ignore = True
+            depth = int(parts[0].split(">")[0].strip("<"))
+            if len(symbol_stack) == (depth - 1) and depth > 0:
+                symbol_stack.append(symbol)
+            elif symbol and "name" in symbol:
+                if symbol["debug_type"] == "DW_TAG_variable":
+                    if "start_address" not in symbol:
+                        pass
+                    else:
+                        symbols_by_memory_address[symbol["start_address"]] = symbol
+                elif symbol["debug_type"] in ["DW_TAG_member", "DW_TAG_label", "DW_TAG_typedef", "DW_TAG_enumerator", "DW_TAG_enumeration_type", "DW_TAG_base_type", "DW_TAG_structure_type", "DW_TAG_compile_unit", "DW_TAG_union_type"]:
+                    # skip symbols that don't end up in memory. the type info is available through the debug address map
+                    pass
+                else:
+                    if symbol["name"] in all_symbols:
+                        # print(depth, symbol["name"])
+                        # print(symbol)
+                        # print(all_symbols[symbol["name"]])
+                        # print()
+                        pass
+                    all_symbols[symbol["name"]] = symbol
+            elif symbol and symbol["debug_type"] == "DW_TAG_GNU_call_site_parameter" and "call_site_value" in symbol:
+                parent = -1
+                while symbol_stack[parent]["debug_type"] != "DW_TAG_subprogram":
+                    parent -= 1
+                parent = symbol_stack[parent]
+
+                # Only point to ROM
+                addr = symbol["call_site_value"]
+                if 0x2000 <= addr < 0x20000000:
+                    if "outgoing_pointers" not in parent:
+                        parent["outgoing_pointers"] = set()
+                    parent["outgoing_pointers"].add(addr)
+                    if addr not in symbols_by_memory_address:
+                        symbols_by_memory_address[addr] = symbol
+                        min_call_site_param = min(addr, min_call_site_param)
+                        symbol["name"] = "name{:x}".format(addr)
+            address = parse_hex(parts[0].split("<")[-1].strip(">:"))
+            symbol = {"debug_address": address, "debug_type": debug_type, "other": []}
+            if debug_type == "DW_TAG_structure_type":
+                symbol["struct"] = {}
+            elif debug_type == "DW_TAG_array_type":
+                symbol["subtype"] = None
+                symbol["bound_count"] = 0
+                symbol["maxlen"] = 0
+            elif debug_type == "DW_TAG_subrange_type":
+                symbol_stack[-1]["subtype"] = symbol
+            symbols_by_debug_address[address] = symbol
+        elif ignore:
+            continue
+        elif line[:4] == "    ":
+            tag = parts[1].strip(":")
+            if tag == "DW_AT_name":
+                symbol["name"] = parts[-1]
+            elif tag == "DW_AT_type":
+                symbol["type"] = int(parts[-1].strip("<>"), 0)
+                if symbol["debug_type"] == "DW_TAG_subrange_type":
+                    if not symbol_stack[-1]["subtype"]:
+                        symbol_stack[-1]["subtype"] = symbol
+                    elif symbol_stack[-1]["subtype"]["type"] == symbol["type"]:
+                        second_subtype = True
+                    else:
+                        raise RuntimeError()
+            elif tag == "DW_AT_upper_bound":
+                # Skip arrays with length defined by other variables
+                if parts[-1][0] != "<":
+                    upper_bound = int(parts[-1])
+                    if symbol_stack[-1]["bound_count"] > 0:
+                        symbol_stack[-1]["maxlen"] *= upper_bound + 1
+                    else:
+                        symbol_stack[-1]["maxlen"] = upper_bound + 1
+                    symbol_stack[-1]["bound_count"] += 1
+            elif tag == "DW_AT_byte_size":
+                symbol["size"] = int(parts[-1])
+            elif tag == "DW_AT_inline":
+                symbol["inlined"] = True
+            elif tag == "DW_AT_low_pc":
+                addr = int(parts[-1], 0)
+                symbols_by_memory_address[addr] = symbol
+            elif tag == "DW_AT_location":
+                if parts[-2] == "(DW_OP_addr:":
+                    addr = parse_hex(parts[-1].strip(")"))
+                    if addr > 0:
+                        symbol["start_address"] = addr
+            elif tag == "DW_AT_linkage_name":
+                symbol["linkage_name"] = parts[-1]
+                symbols_by_linkage_name[symbol["linkage_name"]] = symbol
+            elif tag == "DW_AT_data_member_location":
+                symbol_stack[-1]["struct"][int(parts[-1])] = symbol
+            elif tag == "DW_AT_GNU_call_site_value":
+                if parts[-2] == "(DW_OP_addr:":
+                    symbol["call_site_value"] = parse_hex(parts[-1].strip(")"))
+            else:
+                symbol["other"].append(line)
+                #print(parts)
+                pass
+        else:
+            #print(line)
+            pass
+
+    MEMORY_NONE = 0
+    MEMORY_POINTER = 1
+    MEMORY_PY_OBJECT = 2
+
+    def get_size(t):
+        if "size" in t:
+            return t["size"]
+        return get_size(symbols_by_debug_address[t["type"]])
+
+    def get_pointer_map(t, depth=0):
+        if t["debug_type"] == "DW_TAG_pointer_type":
+            return {0: MEMORY_POINTER}
+        elif t["debug_type"] in ["DW_TAG_const_type", "DW_TAG_typedef", "DW_TAG_member", "DW_TAG_subrange_type", "DW_TAG_volatile_type"]:
+            if "name" in t and t["name"] == "mp_rom_obj_t":
+                return {0: MEMORY_PY_OBJECT}
+            return get_pointer_map(symbols_by_debug_address[t["type"]], depth+1)
+        elif t["debug_type"] in ["DW_TAG_base_type", "DW_TAG_enumeration_type"]:
+            return {}
+        elif t["debug_type"] == "DW_TAG_union_type":
+            # skip for now
+            return {}
+        elif "struct" in t:
+            combined_map = {}
+            for offset in t["struct"]:
+                member = t["struct"][offset]
+                submap = get_pointer_map(member)
+                for suboffset in submap:
+                    combined_map[offset + suboffset] = submap[suboffset]
+            return combined_map
+        elif "subtype" in t:
+            subtype = symbols_by_debug_address[t["type"]]
+            pmap = get_pointer_map(subtype, depth+1)
+            size = get_size(subtype)
+            expanded_map = {}
+            for i in range(t["maxlen"]):
+                for offset in pmap:
+                    expanded_map[size * i + offset] = pmap[offset]
+            return expanded_map
+        else:
+            print("no recurse", t)
+            pass
+        return {}
+
+    # Do a second pass to dereference the types
+    for symbol_address in symbols_by_memory_address:
+        symbol = symbols_by_memory_address[symbol_address]
+        if "type" in symbol:
+            if symbol["debug_type"] == "DW_TAG_variable":
+                symbol["pointer_map"] = get_pointer_map(symbols_by_debug_address[symbol["type"]])
+            type_string = []
+            t = symbol["type"]
+            offset = []
+            while t != None:
+                t_symbol = symbols_by_debug_address[t]
+                t = t_symbol.get("type", None)
+                if "name" in t_symbol:
+                    type_string.append(t_symbol["name"])
+                elif t_symbol["debug_type"] == "DW_TAG_array_type":
+                    type_string.append("[]")
+                elif t_symbol["debug_type"] == "DW_TAG_pointer_type":
+                    type_string.append("*")
+                elif t_symbol["debug_type"] == "DW_TAG_const_type":
+                    type_string.append("const")
+                elif t_symbol["debug_type"] == "DW_TAG_volatile_type":
+                    type_string.append("volatile")
+                else:
+                    #print("  ", t_symbol)
+                    pass
+            type_string.reverse()
+            symbol["type_string"] = " ".join(type_string)
+        #print(symbol_name, symbol["debug_type"], symbol.get("type_string", ""))
+
+    # print()
+    # print()
+    # print(all_symbols["mp_builtin_module_table"])
+    # return
+
+    # Gather size and call info
+    text_dump = objdump("-Dz", "-j", ".text", elf_filename)
+    text_dump_lines = text_dump.stdout.decode("utf-8").split("\n")
+    section = None
+    symbol = None
+    symbol_type = None
+    for line in text_dump_lines[4:]:
+        if line.startswith("Disassembly of section"):
+            section = line.split()[-1].strip(":")
+        elif not line:
+            if symbol and "end_address" not in symbol:
+                symbol["end_address"] = last_address
+                symbol["size"] = last_address - symbol["start_address"]
+                symbol = None
+            continue
+        elif line[0].isnumeric():
+            symbol_address, symbol_name = line.split()
+            symbol_address = parse_hex(symbol_address)
+            symbol_name = symbol_name.strip("<>:")
+            if symbol_name in symbols_by_linkage_name:
+                linked_name = symbol_name
+                symbol = symbols_by_linkage_name[symbol_name]
+                if "name" in symbol:
+                    non_linkage = symbol["name"]
+                    if not non_linkage.startswith("__builtin"):
+                        symbol_name = non_linkage
+                all_symbols[symbol_name] = symbol
+                if "name" not in symbol:
+                    symbol["name"] = symbol_name
+            elif symbol_address in symbols_by_memory_address:
+                all_symbols[symbol_name] = symbols_by_memory_address[symbol_address]
+                if "name" not in all_symbols[symbol_name]:
+                    all_symbols[symbol_name]["name"] = symbol_name
+            elif symbol_name not in all_symbols:
+                if symbol_name == "nlr_push_tail_var":
+                    fake_type = all_symbols["mp_obj_get_type"]["type"]
+                    symbol = {"debug_type": "DW_TAG_variable", "name": symbol_name, "type": fake_type}
+                else:
+                    print(line)
+                    print(symbol_name, symbol_address)
+                    symbol = {"debug_type": "DW_TAG_subprogram", "name": symbol_name}
+                all_symbols[symbol_name] = symbol
+                #raise RuntimeError()
+
+            symbol = all_symbols[symbol_name]
+            symbol["start_address"] = symbol_address
+            symbols_by_memory_address[symbol_address] = symbol
+            symbol["section"] = section
+
+            if symbol["debug_type"] == "DW_TAG_subprogram":
+                symbol["outgoing_jumps"] = set()
+                symbol["incoming_jumps"] = set()
+                symbol_type = None
+            elif symbol["debug_type"] == "DW_TAG_variable":
+                symbol["outgoing_pointers"] = set()
+                symbol_type = symbols_by_debug_address[symbol["type"]]
+            all_symbols[symbol_name] = symbol
+
+        elif line[0] == " ":
+            parts = line.strip().split()
+            last_address = parse_hex(parts[0].strip(":"))
+
+            offset = last_address - symbol["start_address"]
+            if "pointer_map" in symbol:
+                if offset not in symbol["pointer_map"]:
+                    #print(offset, symbol)
+                    pass
+                else:
+                    ref = parse_hex(parts[1])
+                    pointer_style = symbol["pointer_map"][offset]
+                    if pointer_style == MEMORY_POINTER:
+                        symbol["outgoing_pointers"].add(ref & 0xfffffffe)
+                    elif pointer_style == MEMORY_PY_OBJECT and ref & 0x3 == 0:
+                        symbol["outgoing_pointers"].add(ref)
+            if len(parts[1]) == 8 and parts[1][0] == "0":
+                addr = parse_hex(parts[1])
+                if 0x2000 <= addr < 0x20000000:
+                    if "outgoing_pointers" not in symbol:
+                        symbol["outgoing_pointers"] = set()
+                    symbol["outgoing_pointers"].add(addr)
+            elif "<" in line and symbol["debug_type"] == "DW_TAG_subprogram":
+                if line[-1] == ">":
+                    jump_to = parts[-1].strip("<>").split("+")[0]
+                    if "name" not in symbol:
+                        print(jump_to)
+                        print(symbol)
+                    if jump_to != symbol["name"] and jump_to not in BAD_JUMPS:
+                        symbol["outgoing_jumps"].add(jump_to)
+                        #print(symbol_name, jump_to)
+                        if jump_to == "_etext":
+                            print(line)
+                elif "UNDEFINED" in line:
+                    continue
+                elif parts[2] == "ldr":
+                    continue
+                else:
+                    print(line)
+        else:
+            #print(line)
+            pass
+
+    # print()
+    print(hex(min_call_site_param))
+    print(all_symbols["exception_table"])
+    # return
+
+    print("converting outgoing pointers to names")
+
+    # Convert outgoing pointers to names from addresses
+    for symbol_name in all_symbols:
+        symbol = all_symbols[symbol_name]
+        if "outgoing_pointers" not in symbol:
+            continue
+        converted = set()
+        for outgoing in symbol["outgoing_pointers"]:
+            if outgoing in symbols_by_memory_address:
+                outgoing = symbols_by_memory_address[outgoing]
+                #print(outgoing)
+                if outgoing["debug_type"] in ["DW_TAG_GNU_call_site", "DW_TAG_lexical_block"]:
+                    continue
+                if outgoing["name"] == "audioio_wavefile_type":
+                    print(outgoing)
+                converted.add(outgoing["name"])
+        symbol["outgoing_pointers"] = converted
+
+    print("linking back")
+    # Link back
+    for symbol_name in all_symbols:
+        symbol = all_symbols[symbol_name]
+        if "outgoing_jumps" in symbol:
+            for outgoing in symbol["outgoing_jumps"]:
+                if outgoing not in all_symbols:
+                    #print(outgoing, symbol_name)
+                    continue
+                #print(all_symbols[outgoing], symbol_name)
+
+                referenced_symbol = all_symbols[outgoing]
+                if "incoming_jumps" not in referenced_symbol:
+                    #print(symbol_name, "->", outgoing)
+                    referenced_symbol["incoming_jumps"] = set()
+                referenced_symbol["incoming_jumps"].add(symbol_name)
+        if "outgoing_pointers" in symbol:
+            for outgoing in symbol["outgoing_pointers"]:
+                if outgoing not in all_symbols:
+                    #print(outgoing, symbol_name)
+                    continue
+                #print(all_symbols[outgoing], symbol_name)
+
+                referenced_symbol = all_symbols[outgoing]
+                if "incoming_pointers" not in referenced_symbol:
+                    #print(symbol_name, "->", outgoing)
+                    referenced_symbol["incoming_pointers"] = set()
+                referenced_symbol["incoming_pointers"].add(symbol_name)
+
+    print(all_symbols["exception_table"])
+
+    # Chart it all
+    print("charting {} symbols".format(len(all_symbols)))
+    callgraph = pgv.AGraph(directed=True)
+    for i, symbol_name in enumerate(all_symbols):
+        symbol = all_symbols[symbol_name]
+        # print(i, symbol_name)
+        # if "outgoing_jumps" in symbol:
+        #     print("   ", len(symbol["outgoing_jumps"]), "jumps")
+        # if "outgoing_pointers" in symbol:
+        #     print("   ", len(symbol["outgoing_pointers"]), "ptrs")
+        # if i > 3000:
+        #     break
+        if ("incoming_jumps" not in symbol or len(symbol["incoming_jumps"]) == 0) and ("incoming_pointers" not in symbol or len(symbol["incoming_pointers"]) == 0):
+            #print(symbol_name)
+            continue
+        if "start_address" not in symbol:
+            continue
+        callgraph.add_node(symbol_name)
+        if "outgoing_jumps" in symbol:
+            for outgoing in symbol["outgoing_jumps"]:
+                callgraph.add_edge(symbol_name, outgoing)
+        if "outgoing_pointers" in symbol:
+            for outgoing in symbol["outgoing_pointers"]:
+                callgraph.add_edge(symbol_name, outgoing, color="red")
+        #print(symbol_name, symbol)
+
+    # Style all of the nodes
+    print("styling")
+    for node in callgraph.iternodes():
+        if node.name not in all_symbols:
+            continue
+        symbol = all_symbols[node.name]
+        node.attr["shape"] = "box"
+        text_width_ish = len(node.name) * 0.1
+        if "size" not in symbol:
+            print(symbol)
+        size = symbol["size"] / 8
+        square_size = size ** 0.5
+        if text_width_ish > square_size:
+            w = text_width_ish
+            h = size / text_width_ish
+        else:
+            w = square_size
+            h = square_size
+        node.attr["width"] = w
+        node.attr["height"] = h
+        node.attr["label"] = node.name + "\r\n" + str(symbol["size"]) + " bytes"
+        node.attr["style"] = "filled"
+
+        incoming = 0
+        if "incoming_jumps" in symbol:
+            incoming += len(symbol["incoming_jumps"])
+        if "incoming_pointers" in symbol:
+            incoming += len(symbol["incoming_pointers"])
+
+        if node.name in SPECIAL_NODE_COLORS:
+            node.attr["color"] = SPECIAL_NODE_COLORS[node.name]
+        elif incoming == 1:
+            node.attr["color"] = "lightblue"
+        elif incoming > 25:
+            print("delete", node.name, "because it has {} incoming".format(incoming))
+            callgraph.delete_node(node.name)
+        elif incoming > 15:
+            node.attr["color"] = "red"
+
+    print("drawing")
+    callgraph.layout(prog="dot")
+    fn = "callgraph.svg"
+    print(fn)
+    callgraph.draw(fn)
+
+if __name__ == "__main__":
+    do_all_the_things()