Arduino project · Displays and counters · Medium
Ohm Meter with LCD
Measure the value of an unknown resistor and read it in kilo-ohms.
What you will learn
- How a voltage divider reveals a resistor value
- How to rearrange the divider formula
- How a multimeter measures resistance
How it works
A known 10k resistor and the unknown resistor share the 5 V. The reading in the middle tells the unknown value.
Try this next
- Auto-choose between a few reference resistors.
- Sort resistors into low, mid and high with LEDs.
- Test an LDR.
The simulator program and explanation on this page are original. The idea follows a classic Arduino project that students have built for years.
Parts: sensors and actuators (tap to show or hide)
Try the inputs (virtual sensors)
Pins (you can change them)
| Part | Arduino pin (change it here) | How to wire it |
|---|
Every wire, one by one
Red rail = 5 V from the Arduino 5V pin. Black rail = GND. The coloured wires carry signals. Match the wire colours on the drawing to this list.
| # | Colour | From (part and leg) | To |
|---|
Steps run from top to bottom, then start again. While the simulation runs, the active step is highlighted in green.
Quantities come from the parts you added. The store links open a search for that item on Robu.in, Amazon.in and ThinkRobotics, so you always see what is in stock today. Check the model, voltage and price before you order.
| # | Item | Qty | Search term | Buy / compare |
|---|
The PDF has the circuit sketch, pin table, every wire, sequence, full code, the parts list with store links, do’s and don’ts for each part, and the safety notes. The project file lets you come back and keep editing.
In the real world
An ohm meter
Move the resistance slider. The needle shows how much the part resists.
Tip: use the gold tab at the bottom of the circuit drawing to pull the real-world view up over the Arduino board. Your parts stay visible above it, so you can press a button and watch the real scene react.
- Resistance = the part under test