When doing projects we sometimes find tools too expensive. We look for affordable alternatives or make those ourselves.
- Power (usage) meter: to find out what a device really consumes (and how long one can expect a battery to last) https://www.instructables.com/id/Make-Your-Own-Power-MeterLogger/ and https://learn.sparkfun.com/tutorials/ltc4150-coulomb-counter-hookup-guide/running-the-example-code
- nScope: a portable electronics lab http://www.nscope.org
- soldering fingers https://www.stlfinder.com/model/soldering-fingers-s9l7BnvM/5009404