From 74b4098608d2ed05586d70af7542d40963bad72b Mon Sep 17 00:00:00 2001
From: Martin Preuss <martin@aquamaniac.de>
Date: Tue, 27 Jan 2026 20:32:38 +0100
Subject: [PATCH] ili9341: tested backlight dimming (doesn't work with my
 displays, either)

probably the LED pins are hardcoded with my displays. They respond neither
to PWM on the LED pin nor to ili9341 commands.
---
 avr/modules/lcd2/ili9341/main.asm | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/avr/modules/lcd2/ili9341/main.asm b/avr/modules/lcd2/ili9341/main.asm
index 728f202..1290e24 100644
--- a/avr/modules/lcd2/ili9341/main.asm
+++ b/avr/modules/lcd2/ili9341/main.asm
@@ -46,7 +46,7 @@ ILI9341_Init:
   rcall ILI9341_Reset
   rcall ILI9341_LeaveSleepMode
   
-  ldi r16, 0xff
+  ldi r16, 0x20
   rcall ILI9341_SetBacklight
 
   sec
@@ -146,13 +146,14 @@ ILI9341_SetBacklight:
 ILI9341_SetBacklight_on:
   sbi ILI9341_LED_OUTPUT, ILI9341_LED_PIN
 ret ; DEBUG
+
   push r16
     rcall ili9341BeginSpi
     
     ldi r16, ILI9341_CMD_WRITECTLDISPLAY
     rcall ili9341SendCommand
-  ;  ldi r16, 0b00100100
-    ldi r16, 0x24
+    ; BCTRL=1, DD=1, BL=1   (or: 0x24 reported to work)
+    ldi r16, (1<<5) | (1<<3) | (1<<2)
     rcall ili9341SendData
 
     ldi r16, ILI9341_CMD_SETDSPBRIGHTNESS
@@ -160,10 +161,10 @@ ret ; DEBUG
   pop r16
   rcall ili9341SendData
 
-  ldi r16, 0xbe
-  rcall ili9341SendCommand
-  ldi r16, 0x0f
-  rcall ili9341SendData
+;  ldi r16, 0xbe
+;  rcall ili9341SendCommand
+;  ldi r16, 0x0f
+;  rcall ili9341SendData
 
   rcall ili9341EndSpi