MCP3021-RK (community library)


Name Value
Name MCP3021-RK
Version 0.0.1
Installs 2046
License MIT
Download .tar.gz

Particle driver for MCP3021 10-bit I2C ADC

Example Build Testing

Device OS Version:

This table is generated from an automated build. Success only indicates that the code compiled successfully.

Library Read Me

This content is provided by the library maintainer and has not been validated or approved.


Particle library for MCP3021 I2C 10-bit ADC

I'm not sure why you'd need this, as the Particle Photon and Electron already have a lot of ADC inputs. I originally did this because I thought I might need an ADC at the end of a long-range I2C bus, but you never know when you might need it so here it is.

The Microchip MCP3021 is a tiny (SOT-23-5), inexpensive (US$1.12 in single quantities) 10-bit ADC with an I2C interface. It operates on from 2.7V to 5.5V, which can also be handy.

I got mine from Digikey but they're widely available.

One issue is that it's only available in the SMT SOT-23-5 package, so it's intended to be included directly on your board. For prototyping, you could use a SOT-23-5 breakout, or build your own.

I built a tiny circuit board for this purpose that contains the chip and two I2C pull-up resistors. The Eagle CAD schematic and layout are included in the eagle directory.

Circuit (image removed)

Board (image removed)

This ADC is fast - it samples during the I2C transaction, so you can call it as often as you want.

Sample program

Here's a simple sample program to read the ADC:

#include "Particle.h"

#include "MCP3021-RK.h"

const unsigned long SAMPLE_PERIOD_MS = 1000;

MCP3021 adc(Wire);
bool haveChip = false;
unsigned long lastSample = 0;

void setup() {

void loop() {
if (millis() - lastSample >= SAMPLE_PERIOD_MS) {
lastSample = millis();

if (!haveChip) {
haveChip = adc.check();
Serial.printlnf("haveChip=%d", haveChip);
if (haveChip) {
Serial.printlnf("value=%u", adc.getSample());
} else {
Serial.println("no MCP3021 detected");

Browse Library Files