Component choices notes

A project log for Floppy Tester

A simple battery cell tester built on a flexible PCB substrate, that connects to cells using magnets

danie-conradieDanie Conradie 05/28/2019 at 20:280 Comments

Some notes on component choices

MIcrocontroller: I chose the Attiny85 since it is cheap, small and can be programmed with the Arduino IDE.

OLED: I would have chosen a smaller OLED display than the 0.96" on a breakout, but it is just larger than the CR2032 battery holder used on the back, making a neat package.

Load switching mosfet: The Vishay SI2318CDS mosfet is used because it has a low RDS(on) (drain-source on resistance), to prevent excessive voltage reading error when the load is switched on. The gate voltage is also low enough to be switched by the coin cell battery (2.5V) and is in the very common SOT-23 footprint, allowing me to subsitute another MOSFET if required for any reason.