Hello,
I am attempting to connect this display to a Teensy 4.0 over SPI.
The development kit I was using to test this display includes a Seeeduino, an Arduino Uno clone that can switch between 5 and 3.3V logic level. Each pin can provide up to 40mA of current.
From this thread, I see that the Teensy 3.0 has a recommended max pin current of 9mA and absolute max pin current of 25mA. When I tried connecting the display breakout directly to the Teensy, the display does not power on. I think the reason is due to high current draw.
I took measurements of the voltage and current through the pins in both configurations, shown below:
Seeeduino:
Teensy:
I tried using the seeeduino for 3.3V power, with shared ground between it and the Teensy. However, it still did not work. I'm thinking each pin individually must be driven at a higher current to enable communication with the display.
To achieve this, I tried connecting the SCK, MOSI, MISO, and !CS pins of the display breakout to the collector of BC547B transistors. 3.3V is applied to the collector, the control pins (13, 11, 12, 9) on the Teensy are connected to the base of each transistor through 1kOhm resistors, and the emitter is connected to ground. The remaining pins are connected from the Seeeduino, 3.3V, shared common ground, !INT (which is a constant HIGH), and !PD(which is a constant HIGH).
This method does not work either. If anyone else has had success driving this type of display, or can provide advice on how I would be able to boost the output current, I would be very appreciative.
I am attempting to connect this display to a Teensy 4.0 over SPI.
The development kit I was using to test this display includes a Seeeduino, an Arduino Uno clone that can switch between 5 and 3.3V logic level. Each pin can provide up to 40mA of current.
From this thread, I see that the Teensy 3.0 has a recommended max pin current of 9mA and absolute max pin current of 25mA. When I tried connecting the display breakout directly to the Teensy, the display does not power on. I think the reason is due to high current draw.
I took measurements of the voltage and current through the pins in both configurations, shown below:
Seeeduino:
Teensy:
I tried using the seeeduino for 3.3V power, with shared ground between it and the Teensy. However, it still did not work. I'm thinking each pin individually must be driven at a higher current to enable communication with the display.
To achieve this, I tried connecting the SCK, MOSI, MISO, and !CS pins of the display breakout to the collector of BC547B transistors. 3.3V is applied to the collector, the control pins (13, 11, 12, 9) on the Teensy are connected to the base of each transistor through 1kOhm resistors, and the emitter is connected to ground. The remaining pins are connected from the Seeeduino, 3.3V, shared common ground, !INT (which is a constant HIGH), and !PD(which is a constant HIGH).
This method does not work either. If anyone else has had success driving this type of display, or can provide advice on how I would be able to boost the output current, I would be very appreciative.