Hello Everyone,
I'm designing a small PCB to help a friend, it would basically be a buzzer for his drone that would function as a normal buzzer when it's connected to power, but on a event of loss of power it would beep at defined intervals to help him find his drone.
I have the schematic attached.
One problem that I'm fighting now is that if I populate the PCB the Attiny85 refuses to be programmed. I troubleshooted the issue with the Li-ion battery charger on the board (MCP73831) and could even reproduce the issue one a breadboard.
I don't understand why I'm having this issue, the ISP header has a power supply that should be different from the +5V and the +Bat voltage supply.
Does anyone has an idea of why is this happening? I can just put a solder jump on the board, and leave if disconnected before programming, but I really want to understand what is going on.
Thank you very much for any lead,
Vitor Henrique