Rambo 1.4 Serial extension/Marlin extra serial ports

Mostly Printed CNC - MPCNC Hardware Development
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I am wondering if the additional serial ports as implemented in Marlin act independently from one another. Meaning is each is it’s own bi-directional communication path? I am currently using a pendant with hard coded buttons via an Arduino that ties into serial port 0 on the serial extension connector. I think it is not getting the correct returns over serial though. I am guessing this may be because serial port 0 is also the USB port that Octoprint is utilizing. Below is from configuration.h . If I set up a second serial port like this and rewire the pendant to serial port 1, I am wondering if it will be isolated from the other connections and the returns will be more readable. Most importantly though, will injected commands still be taken from the second port/host?

/**
 * Select a secondary serial port on the board to use for communication with the host.
 * Currently Ethernet (-2) is only supported on Teensy 4.1 boards.
 * :[-2, -1, 0, 1, 2, 3, 4, 5, 6, 7]
 */
#define SERIAL_PORT_2  1
#define BAUDRATE_2 250000   // :[2400, 9600, 19200, 38400, 57600, 115200, 250000, 500000, 1000000] Enable to override BAUDRATE
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Yes, no interference, and the second serial port’s commands will be taken. I’ve never tried to intermix them though. I’ve never tried sending a command from my pendent while a g-code sender is sending a file over USB. I use one or the other. Obviously you will have to move your pendent wiring to serial port 1.

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Thanks. In my case It is only really for setups, so I don’t foresee any collisions while running a job or anything. I hope. :wink:

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I usually see “uncommanded instruction” or some such message in Openbuilds console when using my serial pendant on a separate serial port, but it doesn’t affect the actual operation of the cnc.