Revive a bricked CH59x that got bad config data. Only works if the bootloader does this reset after 10ms trick every half a second.

revive_ch59x.py

#!/usr/bin/env python
"""
requires pyusb, which should be pippable
have this run in an udev rule, like
SUBSYSTEM=="usb", ATTR{idVendor}=="4348", ATTR{idProduct}=="55e0", MODE="666", RUN+="/bin/sh -c '/path/to/this/script/revive_ch59x.py' >> /tmp/ch59x"
and update the rules with
$ sudo udevadm control --reload-rules && sudo udevadm trigger
Then see the output with
$ tail -f /tmp/ch59x

This likely requires a lot of tries, very often te bootloader resets before config update finishes.
Also have a look at the commented out code, those are worth a try too

Holding the boot button will get this script run almost every time the chip resets,
it seems to always fail with a "not found" exept on power on if the button is not held.
"""
import usb.core
import usb.util

CH_USB_VENDOR_ID1   = 0x4348    # VID 1
CH_USB_VENDOR_ID2   = 0x1a86    # VID 2
CH_USB_PRODUCT_ID   = 0x55e0    # PID
CH_USB_INTERFACE    = 0         # interface number
CH_USB_EP_OUT       = 0x02      # endpoint for command transfer out
CH_USB_EP_IN        = 0x82      # endpoint for reply transfer in
CH_USB_PACKET_SIZE  = 64        # packet size
CH_USB_TIMEOUT      = 5000      # timeout for USB operations

CH_CMD_CHIP_TYPE    = 0xa1
CH_CMD_REBOOT       = 0xa2
CH_CMD_KEY_SET      = 0xa3
CH_CMD_CODE_ERASE   = 0xa4
CH_CMD_CODE_WRITE   = 0xa5
CH_CMD_CODE_VERIFY  = 0xa6
CH_CMD_CONFIG_READ  = 0xa7
CH_CMD_CONFIG_WRITE = 0xa8
CH_CMD_DATA_ERASE   = 0xa9
CH_CMD_DATA_WRITE   = 0xaa
CH_CMD_DATA_READ    = 0xab

CH_STR_CHIP_DETECT  = b'\xa1\x12\x00\x52\x11MCU ISP & WCH.CN'
CH_STR_CONFIG_READ  = (0xa7, 0x02, 0x00, 0x1f, 0x00)
CH_STR_CODE_ERASE   = (0xa4, 0x04, 0x00, 0x08, 0x00, 0x00, 0x00)
CH_STR_DATA_ERASE   = (0xa9, 0x05, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02)
CH_STR_REBOOT       = (0xa2, 0x01, 0x00, 0x01)

CH_XOR_KEY_LEN      = 8

# Find the device
device = usb.core.find(idVendor=CH_USB_VENDOR_ID1, idProduct=CH_USB_PRODUCT_ID)

if device is None:
    print("ch59x not found")
    exit(0)

# Set the active configuration. With no arguments, the first configuration will be the active one
device.set_configuration()

# Get an endpoint instance
cfg = device.get_active_configuration()
intf = cfg[(0, 0)]

# Claim the interface
usb.util.claim_interface(device, intf)

# chip detect, should be [161, 0, 2, 0, 146, 34]
device.write(CH_USB_EP_OUT, CH_STR_CHIP_DETECT)
print(device.read(CH_USB_EP_IN, CH_USB_PACKET_SIZE, CH_USB_TIMEOUT))

# config read, WeAct default is [167, 0, 26, 0, 31, 0, 255, 255, 255, 255, 255, 255, 255, 255, 77, 15, 255, 79, 0, 2, 3, 0, 21, 55, 79, 16, 83, 92, 183, 163]
device.write(CH_USB_EP_OUT, CH_STR_CONFIG_READ)
print(device.read(CH_USB_EP_IN, CH_USB_PACKET_SIZE, CH_USB_TIMEOUT))

# Write good config, like the WeAct modules came with
#device.write(CH_USB_EP_OUT, b'\xa8\x0e\x00\x07\x00' + bytes([255, 255, 255, 255, 255, 255, 255, 255, 77, 15, 255, 79]))
#print(device.read(CH_USB_EP_IN, CH_USB_PACKET_SIZE, CH_USB_TIMEOUT))

# Code Erase can be tried, but might not be necessary
#device.write(CH_USB_EP_OUT, CH_STR_CODE_ERASE)
#print(device.read(CH_USB_EP_IN, CH_USB_PACKET_SIZE, CH_USB_TIMEOUT))

# Same for Data Erase, might not be necessary
#device.write(CH_USB_EP_OUT, CH_STR_DATA_ERASE)
#print(device.read(CH_USB_EP_IN, CH_USB_PACKET_SIZE, CH_USB_TIMEOUT))

# Reboot definitely seems necessary after config update
device.write(CH_USB_EP_OUT, CH_STR_REBOOT)
print(device.read(CH_USB_EP_IN, CH_USB_PACKET_SIZE, CH_USB_TIMEOUT))

# Release the interface when done
usb.util.release_interface(device, intf)
print('done')