Reset to bootloader fails on stock firmware 03.2.85

[Elemecca]

The update tool (tl866 self update) is unable to reset to the bootloader from stock firmware version 03.2.85 (the latest as of this writing). The reset command that works on earlier versions does something, but when it completes the stock firmware is still running.

The official client software refuses to update a device that's already running 03.2.85, so it's not possible to get a USB capture of it resetting a device running that version. It's therefore probable that this issue won't be resolved until XGecu releases a new firmware version.

This was mentioned in #23 before it was merged, but it was decided that merging bootloader support was too important to wait for a solution.

Until this is resolved, to flash the open firmware on a device running stock version 03.2.85 or newer it will be necessary to use the hardware workaround described in the README (short pin RC1 of the PIC to Vcc).

[d235j]

I've tested this on three devices and don't seem to be experiencing this problem at all — either with this tool, or radioman's updater.

[d235j]

Based on radioman's research at
https://www.eevblog.com/forum/blog/eevblog-411-minipro-tl866-universal-programmer-review/msg1713203/#msg1713203:
It looks like the official firmware checks the protection status of the chip and will refuse to reset into bootloader if it is not set.
The recommended solution is to enable code protection before flashing back to official firmware.