I have two Arduino Unos with XBee shields that I’m trying to get to talk to each other.
In troubleshooting, I find there is no connectivity between the XBee pins 2 and 3 (DOUT and DIN) with the Arduino pins, either TX and RX or D2 and D3, no matter where the DLINE/UART switch is set.
My understanding is that XBee pins 2 and 3 should be connected to Arduino pins TX and RX (in the UART switch position) or to Arduino pins D2 and D3 (in the DLINE switch position). The schematic seems to confirm this.
My Xbee modules work fine (to the extent I can verify) with the XBee USB Explorer.
Looking at the schematic at https://cdn.sparkfun.com/datasheets/Wir … ld_v15.pdf the connection between the XBEE and the switch goes through the level shifters (Q1, Q2) so you would not see continuity. In addition the connections from the switch to D2 and D3 go through jumpers SJ1 and SJ3. Double check that they are bridged with solder on your shield.
One difference that I see between the explorer and the shield is that the explorer drives CTS, RTS, and DTR but the shield leaves them floating. It doesn’t look like the XBee needs those during normal operations, but you could try tying CTS and DTR low.
I was experiencing this with two separate XBee shields and Unos, and using the tutorial example sketch XBee_Serial_Passthrough.ino. My solder joints on D2 and D3 header pins are good (verified between the pin and the corresponding through-hole); all other relevant solder joints also verified.
I say “was experiencing” because I tried again today, and achieved bidirectional communication between Uno and Explorer. Apart from pulling things apart a few times, the only thing I’ve changed is updating XCTU from 6.5.0 to 6.5.1. So I can’t say why it changed. (Can’t rule out operator error, though I hope I was sufficiently careful to minimize that possibility before posting.) In any case, thanks for the help!
