SPI communication between slave Arduino and Master Raspberry Pi

Projects Networking, Protocols, and Devices
4

OMG! Your internet search on how to break down a multibyte number into individual bytes has failed!

OK, here is some code on how to break down a thingy into individual thingies.

if (!PassTwo)
        {
          rx_frame.FIR.B.FF = CAN_frame_std;
          rx_frame.MsgID = 1;
          rx_frame.FIR.B.DLC = 8;
          rx_frame.data.u8[0] = *item & 0xFF;
          rx_frame.data.u8[1] = (*item >> 8) & 0xFF;
          rx_frame.data.u8[2] = (*item >> 16) & 0xFF;
          rx_frame.data.u8[3] = (*item >> 24) & 0xFF;
          PassTwo = true;
        } else {
          rx_frame.data.u8[4] = *item & 0xFF;;
          rx_frame.data.u8[5] = (*item >> 8) & 0xFF;
          rx_frame.data.u8[6] = (*item >> 16) & 0xFF;
          rx_frame.data.u8[7] = (*item >> 24) & 0xFF;
          ESP32Can.CANWriteFrame(&rx_frame); // send items over CAN buss
          PassTwo = false;
        }