Hardware-Handshake (RTS) do not work

[Bernd-Wissler-KBR]

SerialPort Version

12.0.0

Node Version

v20.7.0

Electron Version

No response

Platform

Linux pkcm4test 6.1.21-v8+ #1642 SMP PREEMPT Mon Apr 3 17:24:16 BST 2023 aarch64 GNU/Linux
=> Raspberry CM4

Architecture

ARM V8

Hardware or chipset of serialport

Raspberry CM4

What steps will reproduce the bug?

const { SerialPort  } = require('serialport')

const port = new SerialPort({ 
	path: '/dev/ttyAMA1', 
	baudRate: 38400, 
	autoOpen: true,
	parity: 'even',
	dataBits: 8,
	stopBits: 1,
	rtscts:true
})

port.open(function (err) {
	if (err) {
		return console.log('Error opening port: ', err.message)
	}
	console.log('Port opened! Starting timer')

	setInterval(()=>{
		console.log('Send HELLO')
		port.write("HELLO",function(err){
			if (err) {
				return console.log('Error on write: ', err.message)
			}			
			port.drain(function(){
				console.log('- port data written')
			})
		});
		
	},1000)
})

What happens?

The data is sent, but the RTS signal is not switched!
We tested it with an Oszilloscope!

The RTS signal could be switched back and forth with the manual command: port.set({rts:true/false}).
But we can't implement this with nodeJS because the timing would then become unacceptably bad

What should have happened?

I've already seen in the documentation that you probably haven't tested this board (V8) but it should probably work, but maybe you could still give me a tip on how to get it done.

Thank you and best regards to your Team

Additional information

With the following python script the RTS hardware handshake worked as desired!

import serial
import serial.rs485
import time

print("Test UART-Interface")
time.sleep(1)
print("Select Port: \n 0: /dev/ttyAMA0 \n 1: /dev/ttyAMA1 \n 2: /dev/ttyAMA2 \n 3: /dev/ttyAMA3 \n 4: /dev/ttyAMA4 \n 5: /dev/ttyAMA5")
iPortUserInput = int(input("Number: "))

if iPortUserInput == 0:
    Port = "/dev/ttyAMA0"
elif iPortUserInput == 1:
    Port = "/dev/ttyAMA1"
elif iPortUserInput == 2:
    Port = "/dev/ttyAMA2"
elif iPortUserInput == 3:
    Port = "/dev/ttyAMA3"
elif iPortUserInput == 4:
    Port = "/dev/ttyAMA4"
elif iPortUserInput == 5:
    Port = "/dev/ttyAMA5"
else:
    quit()

# Open UART
uart = serial.Serial(
    port=Port,
    baudrate=38400,
    bytesize=serial.EIGHTBITS,
    parity=serial.PARITY_EVEN,
    stopbits=serial.STOPBITS_ONE,
    rtscts=True,
    write_timeout=5,
    timeout=1
)
uart.rs485_mode = serial.rs485.RS485Settings(
    rts_level_for_tx=True,
    rts_level_for_rx=False,
    loopback=False,
    delay_before_tx=0.0,
    delay_before_rx=0.0
)
#
# Pint UART Status
print(uart)
time.sleep(3)
#
# Init Counter
iCounter = 0
#
# Test-data
a_byTxData = bytearray([1, 2, 5, 11, 22, 33, 44, 55, 99, 121, 122, 123, 128, 129, 190, 191, 192, 200, 205, 210, 215, 222, 234, 250, 254])
#
# 100 times send loop
while iCounter < 100:
    iCounter = iCounter + 1
    print(iCounter)
    uart.write(a_byTxData)
    # print status
    print(uart.write)
    time.sleep(1)
#
# Close
uart.close()

No response