Testing QinHeng Electronics HL-340 USB-Serial adapter

lsusb lists the device here as

Bus 003 Device 002: ID 1a86:7523 QinHeng Electronics HL-340 USB-Serial adapter

It is often shipped together with the sds011 sensor. The required kernel module is called ch341 and built with the following .config entry:


If you use make nconfig or make menuconfig you will find this module in

-> Device Drivers
   -> USB support (USB_SUPPORT [=y]) 
      -> USB Serial Converter support

I had to set the communication parameters manually to 9600 baud, 8N1 before I could use the device properly:

$ stty -F /dev/ttyUSB0 9600 raw

Is the adapter loading the right kernel module? I've heard that your device may be CH341 compatible:

sudo modprobe ch341