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874 B
874 B
CH552 USB-to-Serial firmware
Toolchain setup
SDCC:
sudo apt install build-essential sdcc
CH554 SDK:
cd ~
git clone https://github.com/Blinkinlabs/ch554_sdcc.git
chprog (for flashing the firmware to a device):
cd ~
git clone https://github.com/ole00/chprog.git
cd chprog
./build.linux.sh
Usage
Build the firmware using a default serial number:
make
Flash the firmware to a device:
make flash_patched
Re-programming the firmware
By design, once the USB to serial firmware is loaded onto the chip, there isn't an intended way to reflash it using only software. However, if 3.3V is applied to the D+ line through a 10K resistor during power-up, then the CH552 will enter bootloader mode, and a new firmware can be programmed onto the chip. Note that the CH552 flash is only guaranteed for a few hundred flash cycles.