Arduino project · Fire, gas and safety · Medium
Current Meter (Ammeter) with LCD
Shows how much current flows through a battery-powered circuit.
What you will learn
- What current is and how an ACS712 measures it
- Why there is a middle value of 2.5 V
- How to use a sensor with positive and negative values
How it works
The ACS712 gives 2.5 V for no current and 185 mV more for each amp. The sketch converts the reading to amps. Use batteries only for learning.
Try this next
- Add a buzzer for over 2 A.
- Show power: volts times amps.
- Measure a motor starting.
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 ammeter
Move the current slider. The needle swings like a real meter.
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.
- Current sensor = the current