@martinnn said in Protection circuit for Analog Pin: How exactly do you suppose this to function? This is what I put into a online simulator. If I change the impedance on the right then I can adjust the trim pot and it changes the working range. [image: 1551398013598-c8ac1f5a-9119-49ea-a614-6e56c948f1a1-image-resized.png] This is a digital input, not an analog one. Re-read what I wrote about input protection. How much current flows into the input? Draw a schematic including the input protection as in the article you are referring to (hint: Figure 6). Do you mean what you wrote when you said to use an input series resistor. Is the circuit above what you meant? EDIT: I have since found out that the impedance will be minimal. It is just the resistance of a short cable. So less than 1 ohm. Also this device will go into deep sleep in which case there will still be the analog but no power to the FiPy. Won't this then apply a voltage to VDD?

@robert-hh said in Security - IP Protection: @catalin Don't forget to lock the JTAG interface (if possible). There is a fuse to disable JTAG (JTAG_DISABLE). Furthermore, unless you build a firmware with DEBUG enabled, the JTAG IO pins are re-initialised as inputs with pull-down enabled during micropython startup.

@seb Thanks. Shall keep looking out for updates on this. Talking of encryption, the biggest risk is the username/password ( or other credentials stored on the device which allow it to post data to the server ). If this information can be protected, part of the battle is won.