Early versions, prior ver. 1.7, of the cheap and popular CH341A Mini Programmer have a nasty bug where voltage levels on data lines remain at 5V despite the programmer being set to 3.3V with the jumper.
@ddemos1963 came out with an interesting hack to fix the issue in an efficient and artsy way.
Here's what you do.
Sever the connection between between 5V power line and the CH341A chip. With a sharp utility knife, cut the trace on the back of the programmer board.
Connect 3.3v output leg of the voltage regulator to pin 9 of CH341A IC bridging it to a corresponding trace at a nearby capacitor.
Restore power to the chip re-routing 3.3V voltage from 3v3 pin to pin 28 of CH341A IC through 5V pin connector on the header.
libusb: error [get_usbfs_fd] libusb couldn't open USB device /dev/bus/usb/001/003, errno=13
libusb: error [get_usbfs_fd] libusb requires write access to USB device nodesIf you get an error message like this running a programming software, you need to adjust permissions on the USB port for that device.
Create a udev rule file
sudo vi /etc/udev/rules.d/99-ch341a-prog.rulesadd the following content in the file:
# udev rule that sets permissions for CH341A programmer in Linux.
# Put this file in /etc/udev/rules.d and reload udev rules or reboot to install
SUBSYSTEM=="usb", ATTRS{idVendor}=="1a86", ATTRS{idProduct}=="5512", MODE="0666"save the file, reload udev
sudo udevadm control --reload-rules
sudo udevadm triggerthen unplug the programmer and plug it back in a USB port.
- SNANDer or this fork
- microsnander from OpenIPC
- ch341prog
- flashrom
- DIY BCQ CH341A forum (Chinese, use Chrome automatic translation)
- CH341A Programmer (Russian, use Chrome automatic translation)