Projects
After getting a ridiculously good deal on a microscope, I was keen to try out some smaller PCB designs. Naturally, making earrings seemed to be the perfect challenge. Two challenges for this project were fitting everything on onto a tiny board, but optimizing the ATtiny to draw the least amount of current possible and still be functional, allowing the battery life to be extended.
Some design considerations were to have a single button that depending on the duration it was held down, would change the brightness or the pattern currently being displaying. An analogue pin connected to VBAT to monitor the voltage level of the battery. On the start up of the chip, it could flash a certain colour to inform the user how much battery life is left. Having a PFET in series with the VBAT solved the possibility of a user incorrectly placing the CR1220 coin cell battery back to front. Even though there is a "+" symbol on the holder, better safe than sorry.
When designing prototypes, its easier to just accept the fact that the first version will instantly need better design considerations, let alone seeing if its wired correctly. It worked perfectly for this design, as the end product was going to use the ENIG finish, giving it that 'gold' look. Having a cheap first batch with HASL made it less of a expensive exercise at the cost of time.
*Currently testing energy efficiency, will update this progect soon*
