Connecting 2 Photon via SPI

[bko]

Hi @Anglix

I wrote and tested some code over here to test i2c between two Photons:

[solved] Particle Photon not receiving i2c transmission

Hi @kaydend OK, the following code works for me! First the transmitter sending one incrementing byte to address 8 and blinking the D7 LED to show that it is sending: uint8_t val = 0; void setup() { Wire.begin(); pinMode(D7,OUTPUT); } void loop() { delay(1000); digitalWrite(D7,HIGH); Wire.beginTransmission(8); Wire.write(&val,1); Wire.endTransmission(); val++; delay(20); digitalWrite(D7,LOW); } Now the receive side using onReceive: uint8_t data[8]; i…

The thing that everyone seems to forget is that you need a common ground between the devices. So for SPI, you would need MOSI, MISO, SCK and GND between the devices. You technically don't need a chip select unless you have other SPI devices on the same lines, but it doesn't hurt to add the SS wire.