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232 Communication

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Posted · 232 Communication

I would like to attach a comms cable (232) to my UMO+ so that I can monitor it's status and maybe trigger commands.

This (I believe) is essentially the same as the USB connection, but I am wondering if some of the spare pins on the motherboard can be used as a Tx and Rx...

Has anyone done this or have any idea if it's possible?

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    Posted · 232 Communication

    I had a little success with this today.

    I used the J22 connectors to connect a 232 cable to my processor (Crestron)

    I had to edit Configuration.h slightly

    #define SERIAL_PORT 2 \\was #define SERIAL_PORT 0


    #define BAUDRATE 115200 \\was #define BAUDRATE 250000

    I only had to change the baud rate as my processor doesn't support 250000

    When I power up the board I get a reasuring barrage of start up data...



    echo: Last Updated: Oct 20 2015 17:12:59 | Author: (David Braam)

    Compiled: Oct 20 2015

    echo: Free Memory: 3840 PlannerBufferBytes: 1232

    echo:Hardcoded Default Settings Loaded

    echo:Steps per unit:

    echo: M92 X78.74 Y78.74 Z200.00 E836.00

    echo:Maximum feedrates (mm/s):

    echo: M203 X500.00 Y500.00 Z30.00 E25.00

    echo:Maximum Acceleration (mm/s2):

    echo: M201 X9000 Y9000 Z100 E10000

    echo:Acceleration: S=acceleration, T=retract acceleration

    echo: M204 S4000.00 T3000.00

    echo:Advanced variables: S=Min feedrate (mm/s), T=Min travel feedrate (mm/s), B=minimum segment time (ms), X=maximum XY jerk (mm/s), Z=maximum Z jerk (mm/s), E=maximum E jerk (mm/s)

    echo: M205 S0.00 T0.00 B20000 X20.00 Z0.40 E5.00

    echo:Home offset (mm):

    echo: M206 X0.00 Y0.00 Z0.00

    echo:PID settings:

    echo: M301 P22.20 I1.08 D114.00

    Using tool 0.

    echo:SD card ok

    This tells me that I am definitely connected, the tx and rx are the right way round and the baud rates match on both devices.

    Once this happens I then get

    echo:Unknown command: ""

    every few seconds. It seems like it is monitoring for commands and if it gets nothing then it gets upset. I'm not too bothered about that yet, what I really need to work out is why it doesn't respond when I do send commands.

    I'm also not sure yet what commands I can send to get information I need or to control the printer. (have tried some G and M codes but none of them seem to work)

    I think I may have to enable serial 2 to accept and handle control commands somehow...

    But serial communication is a good start.

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