I wan't to power both cores with 1.8V and, only when using the radio, use 3.3V.I have seen there is a VDDRF pin to power the radio but data sheet says it must be connected to the same supply as VDDMiguel
I have the same problem working with a RAK3172 module using two different stlink programmers and with two different custom board designs.It sometimes work with lower speeds, sometimes with 4000Khz but I always have to connect a probe to the SWCLK lin...
