From screen to bench
When you move from 3D to real parts, here is what to buy and when, how not to hurt yourself or burn anything, and what to check when something doesn’t work.
What to buy at each stage
No prices or stores: they change by country. Only buy what your current stage needs.
Stages 1 and 2
Nothing
- You practice in Tinkercad and Wokwi, free in the browser.
- That way you reach stage 3 knowing which board you want.
Stage 3
Your starter kit
- Arduino Uno (or an ESP32) with a USB data cable
- Breadboard and male-to-male jumper wires
- LEDs, assorted resistors (220 Ω, 1 kΩ, 10 kΩ), buttons and a potentiometer
- An HC-SR04 sensor, an SG90 servo and a TT motor
- A TB6612FNG driver and a 4 × AA battery holder
- A basic multimeter: it measures voltage and continuity
Stage 5 and project
Your first robot
- A 2-wheel chassis kit (it includes motors, wheels and caster)
- A power bank for the Arduino
- For drones: wait until you master the final project; LiPo batteries need more care
Safety
- Disconnect before changing wires
- Remove power every time you move something. A misplaced wire with the board on can cause a short.
- Check polarity
- Red is + and black is −. A battery or LED the wrong way round can damage parts.
- LiPo batteries demand respect
- Don’t puncture or bend them, charge them with their charger and never leave them alone. If one swells, stop using it.
- The soldering iron burns
- The tip is hundreds of degrees. Always keep it in its stand, solder with ventilation and wash your hands when done.
- Never touch mains power
- Everything on the roadmap uses batteries, USB or low-voltage supplies. The 120 V or 230 V from a wall socket is not for practice.
- Mind your fingers with motors and props
- Test motors with the wheels off the ground and never power a drone with propellers without holding it down.
My circuit doesn’t work
Check in this order. It is almost always one of these.
- 1
Is it powered?
Measure with the multimeter that voltage arrives. Check the switch and the batteries.
- 2
Are the grounds joined?
The GND of the Arduino, the driver and the batteries must be connected together.
- 3
Is the LED backwards?
The long leg (+) goes toward the pin or positive. Backwards, it doesn’t light.
- 4
Is the wire in the right column?
On a breadboard each column of 5 is joined, and the middle channel separates them.
- 5
Does the pin in the code match the wire?
If the code says pin 9 and the wire goes to 10, nothing happens.
- 6
Does the servo or motor reset the board?
They draw more current than the Arduino gives. Power them separately and join the grounds.
- 7
Does the serial monitor show garbage?
The monitor speed must match the one in Serial.begin().
- 8
The IDE can’t find the board?
Pick the right board and port, and try another cable: some USB cables only charge and don’t carry data.