Take your serial port on the BBB and tie TX to RX. Use Screen or some other program to test your ports.
On 6/10/2016 7:42 AM, [email protected] wrote: > I am trying to get an arduino to communicate with the BeagleBone Black > and send some measured sensor data over via the serial port. I am > using the most recent version of node red to do this. I am running the > latest version of Debian. > > I have confirmed using an oscilloscope that the arduino's serial port > is outputting the information when it is supposed to (it's triggered > by an interrupt sent by the BBB). I can see the serial ports that are > supposedly enabled in /dev and they appear as ttyO1, ttyO2, and ttyO4, > and I have confirmed the port mapping and ruled out wiring issues as > well (I'm using a logic level converter to go from the arduino's 5V to > the BBB's 3.3V level). > > The ports also appear to map like so: > > lrwxrwxrwx 1 root root 5 Jun 9 22:37 ttyO1 -> ttyS1 > lrwxrwxrwx 1 root root 5 Jun 9 22:37 ttyO2 -> ttyS2 > lrwxrwxrwx 1 root root 5 Jun 9 22:37 ttyO4 -> ttyS4 > > Node red also sees these ports and indicated that they are 'connected' > which I assume means opened. > > When I attempt to receive data on the BBB from ANY of these ports I am > unable to see anything on the output in node red or from the command > prompt. > > I am using a baud rate of 300 to rule out timing issues. I have also > confirmed that the arduino's serial settings should be matched to what > the BBB is expecting. Lastly, I have even tried sending simple strings > from one serial port to the other on the BBB itself. > > Has anyone here had this sort of issue and if so, how did you come to > a solution? > > * > TL;DR: *When I attempt to receive data on the BBB from ANY of the UART > ports I am unable to see anything on the output in node red or from > the command prompt. Already ruled out the obvious issues, and the BBB > clearly sees the ports. What could be the issue here? > > json source from nodered: > > [{"id":"1a47c203.f9dc9e","type":"serial-port","z":"1d18ac42.887634","serialport":"/dev/ttyO2","serialbaud":"300","databits":"8","parity":"none","stopbits":"1","newline":"\\n","bin":"false","out":"char","addchar":false},{"id":"879d3b35.230e98","type":"debug","z":"1d18ac42.887634","name":"Sensor > Output > View","active":true,"console":"false","complete":"true","x":385.78334045410156,"y":60.44999694824219,"wires":[]},{"id":"5eef16d7.037da8","type":"serial > in","z":"1d18ac42.887634","name":"Sensor > Data","serial":"1a47c203.f9dc9e","x":124.7833251953125,"y":150.683349609375,"wires":[["879d3b35.230e98"]]},{"id":"52614fb3.59fe2","type":"bbb-discrete-out","z":"1d18ac42.887634","pin":"P8_7","inverting":false,"toggle":true,"defaultState":"1","name":"Interrupt > to > Sensors","x":284.38330078125,"y":348.3000183105469,"wires":[["ff5b799a.86d1a"]]},{"id":"bdbd2367.9d45a","type":"inject","z":"1d18ac42.887634","name":"Poll > Sensors","topic":"","payload":"\\n > int","payloadType":"str","repeat":"","crontab":"","once":false,"x":126.38330078125,"y":283.7333679199219,"wires":[["52614fb3.59fe2"]]},{"id":"ff5b799a.86d1a","type":"trigger","z":"1d18ac42.887634","op1":"int","op2":"0","op1type":"val","op2type":"pay","duration":"250","extend":false,"units":"ms","reset":"","name":"Reset","x":468.08331298828125,"y":352.0333251953125,"wires":[["b8a60fb7.8d86f"]]},{"id":"b8a60fb7.8d86f","type":"bbb-discrete-out","z":"1d18ac42.887634","pin":"P8_7","inverting":false,"toggle":true,"defaultState":"1","name":"Reset > to > HIGH","x":611.38330078125,"y":405.96668243408203,"wires":[[]]},{"id":"7e38a1db.de0088","type":"comment","z":"1d18ac42.887634","name":"Send > Interrupt to > Arduino","info":"","x":385.7833251953125,"y":286.9666748046875,"wires":[]},{"id":"b75bbc4d.e19d18","type":"comment","z":"1d18ac42.887634","name":"Serial > Port > Setup","info":"","x":142.0833282470703,"y":79.08333587646484,"wires":[]}] > > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google > Groups "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send > an email to [email protected] > <mailto:[email protected]>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/beagleboard/7a31375d-5637-4032-bfe8-71d5e37d6ba0%40googlegroups.com > <https://groups.google.com/d/msgid/beagleboard/7a31375d-5637-4032-bfe8-71d5e37d6ba0%40googlegroups.com?utm_medium=email&utm_source=footer>. > For more options, visit https://groups.google.com/d/optout. -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/0135a3e1-4211-36e0-204c-8725f773491f%40gmail.com. For more options, visit https://groups.google.com/d/optout.
