The [RST] callout in the fifth image down is pointing to the [+3.3V] line coming from the LDO, not the [RST] pin.
It looks like R26 is a pull-up resistor. In that image, the top of R26 is [3v3] and the bottom is [RST]. Note that its neighbor C16 is decoupling [RST] with respect to ground.
Although this wiring may be working for folks, it's bad practice and should be corrected. While I haven't tested it, I'm guessing that the reset pulse sent by the TTL-to-serial converter may be sufficiently brief to pull the LDO output low enough that the uC resets. However this shorts the LDO output to ground through the TTL-to-serial converter every time.
Thanks for your work, TheKikGen team! This project writeup is fantastic 🙏🏼
Hi y'all 👋🏼
I found an error on the Wiki article "The Miditech Midiplus 4x4 hack and STM32Duino".
The [RST] callout in the fifth image down is pointing to the [+3.3V] line coming from the LDO, not the [RST] pin.
It looks like R26 is a pull-up resistor. In that image, the top of R26 is [3v3] and the bottom is [RST]. Note that its neighbor C16 is decoupling [RST] with respect to ground.
Although this wiring may be working for folks, it's bad practice and should be corrected. While I haven't tested it, I'm guessing that the reset pulse sent by the TTL-to-serial converter may be sufficiently brief to pull the LDO output low enough that the uC resets. However this shorts the LDO output to ground through the TTL-to-serial converter every time.
Thanks for your work, TheKikGen team! This project writeup is fantastic 🙏🏼