Using Ma3 encoder with Arduino

Other Hardware Sensors
1

Hi,

I have been trying to use this digital 12-bit PWM encoder with my Arduino. Ultimately, I hope to use it with a ESP32 but that is a little more complicated because it requires a logic level shifter, so I decided to first get it to work on a Arduino Uno. When plugged into pin 6, a digital PWM pin, and when running the digitalRead() function, I get values of 0. When plugged into an analog pin and using the analogread () function, I get a small range of numbers from 180 to about 260. On the ESP32, I get a range of numbers from 470-880. The encoder is supposed to output a 4-5v High and a 0.4v low, but the maximum voltage I've been able to measure on the PWM port is 0.7v. What could the issue be?

2

The encoder: MA3 | US Digital

The datasheet: https://cdn.usdigital.com/assets/datasheets/MA3_datasheet.pdf?k=637421902521693835

3

As described in the data sheet, the shaft position is encoded in the output pulse width.

You will need to use Arduino pulsein() or a similar approach to determine the pulse width, and then appropriately scale the result to arrive at position.

4

If you have a PWM version of MA3 you need to measure not a voltage but ON and OFF pulses duration and then do a calculations as described at chapter PWM Ou****tput Operation of MA3 datasheet**.**

To measure a puls duration you can use :

durationOn = pulseIn(pin, HIGH);
durationOff = pulseIn(pin, LOW);
5

jremington:
As described in the data sheet, the shaft position is encoded in the output pulse width.

You will need to use Arduino pulsein() or a similar approach to determine the pulse width, and then appropriately scale the result to arrive at position.

I tried this, but am getting values of 0. Am I incorrect in saying that I should be able to see values of 1 when using digitalRead() because PWM is a measurement of a digital signal?

6

sajivshah:
I tried this, but am getting values of 0. Am I incorrect in saying that I should be able to see values of 1 when using digitalRead() because PWM is a measurement of a digital signal?

You should see a mixed reading of 0s an 1s. If it's always 0 you need to troubleshoot your connections. Do you have an oscilloscope?