adding a backlight polarity flag to Display

2 files changed, 5 insertions, 1 deletions

diff --git a/shared-module/displayio/Display.c b/shared-module/displayio/Display.c
index 299c8ad35..820fbcce6 100644
--- a/shared-module/displayio/Display.c
+++ b/shared-module/displayio/Display.c
@@ -50,7 +50,7 @@ void common_hal_displayio_display_construct(displayio_display_obj_t* self,
         uint8_t set_row_command, uint8_t write_ram_command, uint8_t set_vertical_scroll,
         uint8_t* init_sequence, uint16_t init_sequence_len, const mcu_pin_obj_t* backlight_pin,
         uint16_t brightness_command, mp_float_t brightness, bool auto_brightness,
-        bool single_byte_bounds, bool data_as_commands, bool auto_refresh, uint16_t native_frames_per_second) {
+        bool single_byte_bounds, bool data_as_commands, bool auto_refresh, uint16_t native_frames_per_second, bool backlight_on_high) {
     // Turn off auto-refresh as we init.
     self->auto_refresh = false;
     uint16_t ram_width = 0x100;
@@ -159,6 +159,9 @@ mp_float_t common_hal_displayio_display_get_brightness(displayio_display_obj_t*
 
 bool common_hal_displayio_display_set_brightness(displayio_display_obj_t* self, mp_float_t brightness) {
     self->updating_backlight = true;
+    if (!self->backlight_on_high){
+        brightness = 1.0-brightness;
+    }
     bool ok = false;
     if (self->backlight_pwm.base.type == &pulseio_pwmout_type) {
         common_hal_pulseio_pwmout_set_duty_cycle(&self->backlight_pwm, (uint16_t) (0xffff * brightness));
diff --git a/shared-module/displayio/Display.h b/shared-module/displayio/Display.h
index e5fe0a708..8adaf597f 100644
--- a/shared-module/displayio/Display.h
+++ b/shared-module/displayio/Display.h
@@ -55,6 +55,7 @@ typedef struct {
     bool data_as_commands;
     bool auto_brightness;
     bool updating_backlight;
+    bool backlight_on_high;
 } displayio_display_obj_t;
 
 void displayio_display_background(displayio_display_obj_t* self);