Error: "No STM32 target found!" on previously-working custom F103 board.
I've been working on programming a custom STM32F103 board for a couple of months, using SWD and an ST-LINK V2. For no apparent reason, since 3 days ago, I've been getting the error: "No STM32 target found!" It was literally working fine when I want to bed, and not working the following morning.
I should probably mention that my board has an error in that BOOT0 is left floating, so I've been relying on software resetting when uploading the latest software build to make it boot. (This will be tied to GND in the final version.) BOOT1 is used as a digital input with the internal weak pullup, NRST is has a decoupling cap as per the manual, and the SWDIO and SWCLOCK pins are both connected directly to the ST-LINK and not used for anything else.
I've done obvious things like restarting my PC, trying a spare ST-LINK, different wires, software, etc, without success.
Am I right in thinking that I need to do a full erase of the STM's memory? I've been trying to do this, but it seems that no matter what combination of BOOT0, BOOT1 and RESET I use (bearing in mind that this is tricky to do reliably because my board doesn't have jumpers or a reset button!), I'm still getting the same error. Any suggestions?