Protocentral ADS1293 Arduino Library

Arduino library for the Protocentral ADS1293 3-channel, 24-bit ECG breakout board.

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The ADS1293 is a low-power, 3-channel, 24-bit analog front-end for biopotential measurements, ideal for ECG applications. It features independently programmable channels, flexible input multiplexing, Right Leg Drive (RLD), Wilson Central Terminal (WCT) for precordial leads, and lead-off detection.

Features

• 3 high-resolution 24-bit sigma-delta ADC channels
• Configurable sampling rates (32 to 853 SPS)
• Support for 3-lead and 5-lead ECG configurations
• Built-in Right Leg Drive (RLD) amplifier
• Wilson Central Terminal for precordial lead measurements
• SPI interface

Installation

Arduino Library Manager (Recommended)

1. Open Arduino IDE
2. Go to Sketch → Include Library → Manage Libraries
3. Search for "Protocentral ADS1293"
4. Click Install

Manual Installation

1. Download or clone this repository
2. Copy to your Arduino libraries folder (~/Documents/Arduino/libraries/)

Hardware Setup

Pin Connections

Signal	Arduino UNO	ESP32 (VSPI)
MISO	12	19
MOSI	11	23
SCLK	13	18
CS	4	4
DRDY	2	2
VCC	5V	5V
GND	GND	GND

ECG Electrode Input Mapping

The ADS1293 has 6 input pins (IN1-IN6) that connect to ECG electrodes:

Input	Electrode	Description
IN1	RA	Right Arm
IN2	LA	Left Arm
IN3	LL	Left Leg
IN4	RL	Right Leg (RLD driven)
IN5	V1	Precordial lead (5-lead only)
IN6	WCT	Wilson Central Terminal reference

Lead Configuration

3-Lead ECG (Einthoven's Triangle):

• Channel 1: Lead I = LA - RA (IN2 - IN1)
• Channel 2: Lead II = LL - RA (IN3 - IN1)
• Lead III is calculated: Lead III = Lead II - Lead I

5-Lead ECG (adds precordial lead):

• Channel 1: Lead I = LA - RA
• Channel 2: Lead II = LL - RA
• Channel 3: V1 = IN5 - WCT (Wilson Central Terminal)

Quick Start

3-Lead ECG Example

#include "protocentral_ads1293.h"
#include <SPI.h>

#define DRDY_PIN 2
#define CS_PIN 4

ADS1293 ecg(DRDY_PIN, CS_PIN);

void setup() {
    Serial.begin(115200);
    ecg.begin();

    // Configure for 3-lead ECG
    ecg.configureChannel1(FlexCh1Mode::Default);  // Lead I: LA-RA
    ecg.configureChannel2(FlexCh2Mode::Default);  // Lead II: LL-RA
    ecg.enableCommonModeDetection(CMDetMode::Enabled);
    ecg.configureRLD(RLDMode::Default);
    ecg.configureOscillator(OscMode::Default);
    ecg.configureAFEShutdown(AFEShutdownMode::AllEnabled);
    ecg.setSamplingRate(ADS1293::SamplingRate::SPS_128);
    ecg.configureDRDYSource(DRDYSource::Default);
    ecg.configureChannelConfig(ChannelConfig::Default3Lead);
    ecg.applyGlobalConfig(GlobalConfig::Start);
}

void loop() {
    if (ecg.isDataReady()) {
        auto samples = ecg.getECGData();
        if (samples.ok) {
            Serial.print(samples.ch1);
            Serial.print(',');
            Serial.print(samples.ch2);
            Serial.print(',');
            Serial.println(samples.ch3);
        }
    }
}

ESP32 Setup

For ESP32, use the begin() overload with SPI pin parameters:

#define SCK_PIN 18
#define MISO_PIN 19
#define MOSI_PIN 23

ecg.begin(SCK_PIN, MISO_PIN, MOSI_PIN);

API Reference

Constructor

ADS1293(uint8_t drdyPin, uint8_t csPin, SPIClass *spi = &SPI)

Initialization

Method	Description
begin()	Initialize with default SPI
begin(sck, miso, mosi)	Initialize with custom SPI pins (ESP32)

Data Reading

Method	Description
isDataReady()	Returns true if new samples are available
getECGData()	Returns Samples struct with ch1, ch2, ch3, and ok flag
getECGData(ch1, ch2, ch3)	Reads samples into reference parameters

Configuration

Method	Description
configureChannel1(mode)	Configure channel 1 input mux
configureChannel2(mode)	Configure channel 2 input mux
configureChannel3(mode)	Configure channel 3 input mux
enableCommonModeDetection(mode)	Enable common-mode detection
configureRLD(mode)	Configure Right Leg Drive
configureWilsonCentralTerminal()	Enable WCT for 5-lead ECG
setSamplingRate(rate)	Set output data rate
configureAFEShutdown(mode)	Control AFE power
applyGlobalConfig(mode)	Start/stop conversions

Sampling Rates

ADS1293::SamplingRate::SPS_32   // 32 samples/sec
ADS1293::SamplingRate::SPS_64   // 64 samples/sec
ADS1293::SamplingRate::SPS_128  // 128 samples/sec
ADS1293::SamplingRate::SPS_256  // 256 samples/sec
ADS1293::SamplingRate::SPS_512  // ~533 samples/sec
ADS1293::SamplingRate::SPS_853  // ~1066 samples/sec

Examples

Example	Description
01-3-lead-ECG-stream	Stream 3-lead ECG to Arduino Serial Plotter
02-5-lead-ECG-stream	Stream 5-lead ECG with precordial lead
03-5-lead-ECG-openview	5-lead ECG with Protocentral OpenView protocol

Visualizing Output

Use the Arduino Serial Plotter or Protocentral OpenView to visualize ECG waveforms.

Documentation

For detailed hardware information and application notes, see the ADS1293 breakout board documentation.

License

Hardware: Creative Commons Share-alike 4.0 International

Software: MIT License

See LICENSE.md for details.