Ch340 Driver: Linux
But here’s the paradox: The CH340’s very cheapness has made it the de facto standard for open-source hardware. And because of that, kernel developers have invested serious effort into making the driver bulletproof. The CH340 on Linux today is a success story of open-source pragmatism—a driver written not for a premium product, but for the components that actually ship in millions of devices.
echo "blacklist ch341" | sudo tee /etc/modprobe.d/blacklist-ch341.conf sudo rmmod ch341 Fix : Add your user to the dialout group: linux ch340 driver
But how well does it actually work on Linux? The answer, after years of a rocky history, is surprisingly well—thanks entirely to a robust, mainlined kernel driver that has matured into a model of stability and efficiency. But here’s the paradox: The CH340’s very cheapness
| Metric | CH340 | FTDI FT232RL | |--------|-------|---------------| | Sustained throughput | 11.2 KB/s | 11.5 KB/s | | Max baud rate (stable) | 2 Mbps | 3 Mbps | | CPU usage @115200 | 0.8% | 0.7% | | Latency (worst-case) | 4 ms | 2 ms | echo "blacklist ch341" | sudo tee /etc/modprobe
For professional or medical equipment? Probably not. The lack of guaranteed long-term supply, the chip’s weaker ESD protection, and the absence of manufacturer-provided Linux tools are real concerns.
sudo usermod -a -G dialout $USER # Log out and back in Cause : Power starvation. Many cheap CH340 boards draw power from the USB port’s 5V line and have inadequate decoupling. Fix : Use a powered USB hub or add a 100µF capacitor across VCC and GND on the device. Issue: Baud rate inaccuracies at 250000, 500000, or 1000000 Cause : The CH340’s internal clock (12 MHz or 48 MHz depending on variant) doesn’t divide evenly to these rates. Workaround : Use standard baud rates (9600, 19200, 38400, 57600, 115200, 230400, 460800, 921600). The driver will silently round non-standard rates to the nearest supported value.