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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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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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