Going off of this example, https://www.tutorialspoint.com/arduino/arduino_serial_peripheral_interface.htm, I have been getting errors trying to get the Dash to operate in Slave mode with a NodeMCU being the Master.
SPCR |= _BV(SPE); // turn on SPI in slave mode
Does anyone have a work around for this line? I am just needing to transfer data back and forth from a NodeMCU V. 1.0 and a Dash. I2C had issues as well. NodeMCU would talk to a MEGA, Dash would talk to a MEGA, NodeMCU and Dash seem to not like each other very much. I wanted SPI for the full duplex communications.