I have a Digi XBee Cellular 3G Module on the sixfab XBee Shield on a Raspberry Pi 3 and neither the GPIO nor the USB approach seem to get any response. The switch between GPIO and USB on the shield has no effect, and the modem doesn’t respond on the serial port and does not appear as an USB device.
Is the XBee module compatible and if so, how can I use it from an Rasperry Pi 3?
Hi…as per my knowledge it is compatible. Using just Tx/Rx data lines is fine if the Xbee is used in transparent mode and data loss is acceptable and data IO rate is not too high. The Raspi UART FIFO buffer is shallow and overflow should be expected. The Xbee includes a blocking mode of comms. This is when a packet is sent, received and acknowledged before the next packet is sent. If a packet gets lost or corrupted, it is not acknowledged and a retry is initiated. This is designed to ensure that all packets are received without error. Data loss or corruption in RF links is normal so it can’t be ignored if packet loss is unacceptable. Unless the packets are fed to the XBee at a very slow rate, the UART FIFO will quickly fill up and overflow.