Serial GPIO

[Whitelock-MT]

Hey,

I'm swapping from using GRBL on a Arduino to GRBLHal on a teensy, on Arduino the USB serial port and the GPIO serial are hardwired together, in the teensy this is not the case, I am having trouble changing the serial connection to these pins, help/advice would be appreciated.

End goal is to use a pi as a sender.

Thanks Kindly

[phil-barrett]

Do I understand you correctly, you want to use the UART connection to connect as sender to grblHAL?

If so, in my_machine.h, around line 52, change: #define USB_SERIAL_CDC 2 // 1 for Arduino class library and 2 for PJRC C library. Comment out to use UART communication. to //#define USB_SERIAL_CDC 2 // 1 for Arduino class library and 2 for PJRC C library. Comment out to use UART communication. and rebuild grblHAL.

A better solution is to use ethernet but that takes a bit more work on the pi side.

[Whitelock-MT]

So tried that and while the USB communication stops, the Pi gets no response from the serial connection

(Also tried simple debugging on the Pi's end, it has a python script reading the serial port and if the teensy has the below code on it, then the pi receives the 'Hello' message every second)

void setup() {
  Serial1.begin(115200);
}

void loop() {
  Serial1.println("Hello");
  delay(1000);
}

[phil-barrett]

Stop bits and parity? 8N1, I believe. I've gotten it to work in the past with the Teensy 4.1 though not recently. Terje will probably have some ideas.

[terjeio]

UART communication is working for me with the latest version (and I have used it since the start for debugging so it should work with older versions too).

By default pin 0 (RX) and 1 (TX) is used. How did you wire the Pi?

Stop bits and parity? 8N1, I believe.

Correct.

[phil-barrett]

Do you have USB to serial converter? It might be worth trying that. Most of them have tx/rx lights so you could see if there is activity, if nothing else.

[Whitelock-MT]

Thats the PI's python script, (on the chance ive done something wrong there, tried many different codes to send on the chance it was wrong to send '$$'

#!/usr/bin/env python
# -*- coding: utf-8 -*-
import serial
import time

ser = serial.Serial(
        port='/dev/ttyS0',
        baudrate = 115200,
        parity=serial.PARITY_NONE,
        stopbits=serial.STOPBITS_ONE,
        bytesize=serial.EIGHTBITS,
        timeout=1

time.sleep(1)
ser.write('$$')

while 1:
        x=ser.readline()
        print x

I don't have a USB to serial, though I have another teensy (and an Arduino I could try with) as well as a oscilloscope if I should just monitor the Rx/Tx pins

[terjeio]

Could it be the "naked Teensy" issue? Check the Wiki and this blog post.

If in alarm 10 mode (estop asserted) the controller only responds to real-time report requests - send a ? to get one.

[Whitelock-MT]

It does appear to be a naked teensy problem

pi@Cnc:~ $ cd Desktop/ pi@Cnc:~/Desktop $ nano serial_uart_test.py pi@Cnc:~/Desktop $ python serial_uart.py <Door:1|MPos:0.000,0.000,0.000|Bf:35,1023|FS:0,0|Pn:D>

Thanks so much the both of you.

[phil-barrett]

Great! Glad you got it sorted out.

By the way, if you are writing your own sender, you will want to read up in the Grbl wiki about writing a sender and in the grblHAL Wiki as well.