UsbSerial | Usb serial controller for Android | Wrapper library

I have a simple modbus device (Ebyte MA02-XACX0440) that I'm trying to learn how to work with. Using a third party GUI called serial port monitor (www.serial-port-monitor.org) I was able to more or less "stumble upon" the proper hexadecimal inputs needed to turn a discrete output on and then off. I don't understand these terms of unit, address, coils, registers, etc. and how it all relates when it comes to the hexadecimal aspect. To break down what I think I know so far (below is the hexadecimal string that will turn the first discrete output 'ON'):

0x20 0x05 0x00 0x00 0xFF 0x00 0x8A 0x8B

I know 0x20 is the device address in hex. The documentation of the Ebyte device stipulates that the default hardware address is '31' and that the first software address is '1'. If I understand that correctly, that means my first physical modbus device on the line has an address of '32', and if I were to put additional modbus devices on the line (either RS485 or TCP(?)) that the next device would be '33' and so on.

I know that the next byte 0x05 is 'write coil'.

I don't know what the next two bytes of '0x00' and '0x00' refer to.

The next two bytes are essentially on/off with '0xFF00' being 'ON' and 0x0000 being 'OFF'.

The final two bytes are simply the CRC checksum.

So up to this point I can get my DO (Discrete Output) to turn on, open up, and light up an LED as a simple proof of concept. Now when I take that approach over to using the pymodbus library (my ultimate goal), things don't seem to line up.

I am able to connect to my device using the pymodbus REPL using

I am a hardware design engineer trying to play with high-level-languages recently. These are my first Python codes. I am very far from OOP and all high-level-language shenanigans. I loved Python very much but I am at the very beginning of learning it. Thanks for your help in advance.

I am trying to read serial data from Arduino. This code is running on Raspberry Pi 3+. It doesn't read in the first loop.

Here is the Arduino code that sends dummy data upon request:

Looks like I broke my NodeMCU Lolin esp8266 module, please confirm)

Firstly everything worked fine, but then...

1. I uploaded a bit strange boot.py to play with UART0

I would like to read RFID Cards with NodeJS. I have a basic RFID-Reader (really don't know the model) that is connected via usb with my computer.

I've tried to read the serial data with NPM Package "serialport" using the following code:

after my first question (NodeJS and Serialport – Read RFID Card) I figured out a way to get the correct data.

But now my result is the following:

Background:

I have an old Seagate BlackArmor NAS 110 that I'm trying to install Debian on by following the instructions here: https://github.com/hn/seagate-blackarmor-nas.

I have a couple of USB to TTL serial adapters (one FTDI chipset and the other Prolific) that I've tried and have run into the same issue with both. I have made the connection to the serial port on the board of the NAS using a multimeter to make sure I've gotten the pinout correct.

Problem:

I'm not able to stop the autoboot process by pressing keys and any point during the boot process. The device also does not seem to respond to any keystrokes although they are echoed back.

What I've Tried So Far:

• Using USB to TTL serial adapters with two different chipsets
• Using the adapters on two different computers (MacBook Pro and a ThinkPad)
• Using different operating systems (MacOS, Windows 10, Ubuntu 20.04)
• Using different terminal programs (Screen, Minicom, Putty)
• Turned off hardware and software flow control
• Tested output of adapters by shorting RX and TX pins and seeing keystrokes echoed back
• Commands seem to be sent to device as when I type I see my commands echoed back (not sure if this is supposed to happen)

I've been at this for a few days and can't figure it out. I've also recorded my screen while experiencing the issue: https://streamable.com/xl43br. Can anyone see where I'm going wrong?

Terminal output while experiencing the problem:

Setup: Macbook Pro 2020 with a Satechi USB dongle, which serves the usb connections to the microcontroller. The USB cable suited for file transferring. I am using an ESP32-wroom-32E, but when that failed I also tried with an ESP32-wroom-32D and an ESP32 (v1). All of them are development boards.

Tried to provision with the following command from https://docs.toit.io/getstarted/provision/:

toit serial provision --baud 460800 -p wifi.ssid=toitwifi -p wifi.password=toitware -m esp32-4mb

This resulted in the following:

I have this digital dial indicator : Helios-Preisser Digimet 1722-502". It comes with a capacity to output its reading over a USB serial cable. The USB cable is a special 4 pin connector on the end that plugs into the calipers and a normal USB on the other end.

Although the device comes with special software, I am trying to write a basic python library to communicate with it. Below is the snippet of the manuel which explains the data communication protocol

I am using the python Serial library and have managed to get some communication going with it. Here's what I have so far

Constantly getting a Syntax Error for;