RS232 Connection

RS232 standard interface (also known as EIA RS-232) is one of the commonly used serial communication interface standards, widely applied in data transmission between various devices. Its stability and reliability make it a preferred communication method for many devices. The protocol uses signal levels different from standard 5V to transmit wire data, which can minimize signal interference to the greatest extent. In 3D printer systems, RS232 has higher data transfer rates, better stability, simpler configuration, and better compatibility with host computers compared to CAN.

Tool Board Uses RS232 to Connect to Mainboard

• Please note that the power line of the tool board is not connected to the RS232 signal line but to the 12V-24V power line.

• No recompilation of the D8 mainboard firmware is required.

Search RS232 ID

Precautions before searching for devices

• Before searching for RS232 ID, please ensure the following conditions have been completed
• Please make sure the tool board has been burned with RS232 firmware
• Please make sure the tool board is connected to UTOR or G2T (if the mainboard has built-in RS232, please ignore this paragraph)
• Please make sure the tool board and the host are grounded!! This step is very important

Search RS232 ID

1. Open the browser, enter the IP address of the host computer in the address bar, for example, my host computer IP is 192.168.101.179, just enter it and press Enter

2. Open the WEB interface of the host computer, find in the configuration option on the left sidebar:

fluidd is: {…} , click to enter, you can find printer.cfg

mainsail is: machine, click to enter, you can find printer.cfg

3. Click printer.cfg and then click DEVICES in the top right corner

4. Click SERIAL, then refresh

fluidd refresh

mainsail refresh

5. Copy the ID, click the arrow to copy

fluidd needs to have ttyUSB, and make sure Path_by_hardware exists, this is the RS232_ID

mainsail needs to have ttyUSB, and make sure Path_by_hardware exists, this is the RS232_ID

Fill in RS232 ID

1. Close DEVICES and fill in the ID

Notes

• Please modify the configuration file:

[mcu] 
serial: /tmp/klipper_host_mcu

to

[mcu host] 
serial: /tmp/klipper_host_mcu

• Add:

[mcu]
serial: <replace this with the ID you just queried>
baud: 250000
restart_method:command

Find [MCU] in fluidd

Find [MCU] in mainsail

2. Fill in the ID in the configuration

tip

• After filling in the ID, click SAVE & RESTART in the top right corner

3. If Klipper prompts ADC out of range, this is normal. Connect the heated bed and thermistor to the mainboard, configure the nozzle and heated bed thermistor pins, and save and restart.

dangerous

Note: All IDs mentioned in the document are examples. The actual ID of each mainboard is different. Please fill in the actual ID you obtained.

dangerous

Please note that the ID below cannot be used !!!

serial: /dev/serial/by-id/usb-1a86_USB_Serial-if00-port0