Spi display,audio adapter and teensy 4.1.

C

creaky

Member
Hi, I have tried what I think the docs are telling me are the correct pins for the combination in the heading, but I am not getting any display. Backlight is on and the adafruit library runs and returns serial monitor readouts that make it look like the Comms are working OK. Should the reset be permanently connected to 3.3v or should there be a switch? Do I need to change anything in the library. I am using pins 9-13 and have not connected any touch pins yet.
Thanks
 
The display is this:
I have wired it as in the table below, for the 4.x using alternate pins, 9 for CS, 10 for D/C and have 2 220 Ohm resistors in parallel for the LED.
ILI9341 PinTeensy 3.x
and 4.x
Standard		Teensy 3.x
Audio Board		Notes
VCC
VIN​
VIN​
Power: 3.6 to 5.5 volts
GND
GND​
GND​
CS
10​
21​
Alternate Pins: 9, 15, 20, 21
RESET
+3.3V​
+3.3V​
D/C
9​
20​
Alternate Pins: 10, 15, 20, 21
SDI (MOSI)
11 (DOUT)​
7​
SCK
13 (SCK)​
14​
LED
VIN​
VIN​
Use 100 ohm resistor
SDO (MISO)
12 (DIN)​
12​
T_CLK
13 (SCK)​
14​
T_CS
8​
8​
Alternate: any digital pin
T_DIN
11 (DOUT)​
7​
T_DO
12 (DIN)​
12​
T_IRQ
2​
2​
Optional: can use any digital pin
 
Reset can just be tied to 3.3V with no switch.
You also don't really need resistors on the LED pin, it can be attached straight to 5V though they shouldn't hurt other than making it dimmer.
D/C on pin 10 is fine as long as you don't have the Audio Adapter with an SD card installed.
Most of these types of displays have a built-in 3.3V regulator and like VCC to be 5V rather than something lower.

Try using the ILI9341_t3.h library which is designed for the Teensy rather than the Adafruit one and be sure to define the CS and DC pins you are using along the lines of
Code: 
ILI9341_t3 tft = ILI9341_t3(TFT_CS, TFT_DC);
 
Thanks. Got it working. Had to join 2 breadboards together as the audio adapter covered all the pins needed. I will put it all on stripboard when everything is working as needed.
 
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