Qduino Mini and Micro OLED via SPI interface

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1

I am trying to connect Micro OLED (SparkFun Micro OLED Breakout - LCD-13003 - SparkFun Electronics) to Qduino Mini(Qduino Mini - Arduino Dev Board - DEV-13614 - SparkFun Electronics) via SPI interface. I cannot figure which pins on Qduino correspond to Micro OLed's D/C and CS?

Can you help me figure this out?

Mapped these OK:

OLED -> QDUINO:

GND -> GND
3V3 -> VCC
D1(SDI) -> MOSI
D0(SCK) -> SCK
RST -> RST

Not sure about these two:

OLED -> QDUINO:

D/C -> ?
CS -> ?

2

You can probably use any two digital pins you like for D/C and CS.

3

thanks!

D15 and D16 are respectively SCK and MOSI as per this chart?

4

Yes, your assignments are correct for SCK and MOSI. But RST of the display should be routed to any GPIO pin, same as D/C and CS, not to the reset line of the processor. You will need to change the #defines in the example programs to match your configuration since they default to an Uno pinout. Look for these lines:

#define PIN_RESET 9 // Connect RST to pin 9 (SPI & I2C)
#define PIN_DC 8 // Connect DC to pin 8 (SPI only)
#define PIN_CS 10 // Connect CS to pin 10 (SPI only)

and change the pin numbers to those you’ve used.

5

avr_fred:
But RST of the display should be routed to any GPIO pin, same as D/C and CS, not to the reset line of the processor.

For my education, why not? As long as the RST line is active low, which I have not checked but they normally are, would that not work?

6

Sure, you can use the hardware reset. But be prepared to:

  1. Ensure the rise of VCC and the reset timing meet the device requirements

And then

  1. Edit the library or
  2. Dedicate/waste a pin for the library to initialize or
  3. Find a dummy output pin number for the code to initialize that doesn’t conflict with the actual hardware and compiles correctly (don’t know if there is any compiler/runtime validation)

If I was out of gpio, #3 would be where I start but I’ve never had to do that.

7

connecting hardware RST to Micro OLED RST did not work. used D5 pin for RST and all is working! many thanks for the tips!