Ratiometric Hall Effect Sensors Arduino Interfacing
In the You Tube video above I demonstrated the use of a ratiometric Hall sensor with an Arduino-Atmega168 connected to a liquid crystal display. This page will show how to connect Hall sensors to the Arduino.
See the two previous pages on Hall sensors the video covered:
In Fig. 1 we have a popular analog current measuring module based on a ACS712 sensor from Allegro. Typical for a ratiometric sensor output is 2.5V with no input and also suffers from narrow range and sensitivity.
In Fig. 2 we use a differential amplifier based on a LM358 to both amplify the output and offset the 2.5-volt problem. This gives use a range of 0-3.8 volts. The circuit works the same way with the ACS712 type sensors.
About the Program
An analog to digital converter (ADC) on the Arduino is a 10-bit (1024 steps) unit and over a range of 5 volts is 5.0/1023 = 4.882 mV per step. Here we simply measure the output voltage from the sensor and display that voltage. It's simply a modified version of my TMP37 program and uses the exact same schematic. See Using the TMP37 Temperature Sensor with Arduino
Download Arduino code arduino_vm.txt download, copy and paste to Arduino compiler.
Typical 2 line by 16 character LCD connection to a generic Arduino module.
R1 is used to adjust LCD contrast, pins 15 and 16 are the back light.
- Using Hall Effect Sensors with Alternating Current
- Using Hall Effect Switches and Sensors
- Using Ratiometric Hall Effect Sensors
- Using Hall Effect Sensors with the Arduino-ATMEGA168
- Spec. sheets:
- UGN3013 Hall Switch (PDF file)
- TL173C 12-Volt Ratiometric Hall Sensor (PDF file)
- UGN3503 5-Volt Ratiometric Hall Effect Sensor (PDF file)
- Honeywell SS466 Hall Latch (PDF file)
- Constant Current Circuits with the LM334
- LM317 Constant Current Source Circuits
- ULN2003A Darlington Transistor Array with Circuit Examples
- Tutorial Using TIP120 and TIP125 Power Darlington Transistors
- Driving 2N3055-MJ2955 Power Transistors with Darlington Transistors
- Understanding Bipolar Transistor Switches
- N-Channel Power MOSFET Switching Tutorial
- P-Channel Power MOSFET Switch Tutorial
- H-Bridge Motor Control with Power MOSFETS
- More Power MOSFET H-Bridge Circuit Examples
- Build a High Power Transistor H-Bridge Motor Control