# Microcontroller Sensor Reading Lab Checklist

Use with Wire a Sensor to a Microcontroller: /projects/wire-a-sensor-to-microcontroller/

## Before starting

- [ ] Power off before changing wiring.
- [ ] Check voltage requirements before connecting parts.
- [ ] Do not assume wire color proves function.
- [ ] Use this as a learning checklist, not as a guarantee for a specific board or sensor.
- [ ] Keep the first circuit low-voltage and simple.

## During the lab

- [ ] Write the sensor purpose in one sentence.
- [ ] Copy the board voltage and sensor voltage requirements into the note.
- [ ] Identify power, ground, and signal pins from the source material.
- [ ] Sketch the intended connection before moving wires.
- [ ] Power off and connect only the minimum circuit.
- [ ] Power on and record the expected reading under one test condition.
- [ ] Record the observed reading under the same test condition.
- [ ] If the reading is wrong, check ground and voltage before code changes.
- [ ] Change only one thing: wire, setting, sample condition, or code path.
- [ ] Write the next safe adjustment and stop before adding a second sensor.

## Finished-state checks

- [ ] Sensor purpose is clear.
- [ ] Board voltage is written.
- [ ] Sensor voltage is written.
- [ ] Ground path is identified.
- [ ] Power and signal pins are named.
- [ ] Expected reading and observed reading use the same test condition.
- [ ] The next adjustment changes one thing.
- [ ] The project note says when to stop and verify with a source.

## Common mistakes to avoid

- [ ] Assuming jumper color proves the pin purpose.
- [ ] Connecting power before reading voltage requirements.
- [ ] Changing code and wiring at the same time.
- [ ] Adding more sensors before the first value is explainable.
- [ ] Treating a noisy reading as a software bug before checking ground and measurement conditions.

## Safety and boundary checks

- [ ] Power off before changing wiring.
- [ ] Check voltage requirements before connecting parts.
- [ ] Do not assume wire color proves function.
- [ ] Use this checklist for learning, not as permission to work outside your skill or equipment limits.

## Next step

- [ ] Read a datasheet first pass: /learn/read-a-datasheet-first-pass/