danielnora:
Hello,I have successfully burnt the firmware to a CC2541F256 without voltage converters or any resistors, by directly connecting the DC, DD and RESET pins to an Arduino UNO with the sketch.
I didn't have success previously, I assume, because I had a bad CC2541 chip. When I switched it to a new chip, the upload worked. I don't know if it didn't work because I flashed the HostTest application (from the HostTestRelease), which might have resulted in the chip becoming non-functional.
I am still unable to use the AT commands on the CC2541, even though it is assembled as in the schematic in my previous post. I'm using P1_6 as TX and P1_7 as RX, which I suppose are the TX and RX pins in HM-10.
Daniel
Oohhhh, I missed it the first time I read your post. The HM-10 TX pin is pin 1 (top most pin on the left of the board) and the RX pin is the one just below it. Good luck!