Arduino library for the Texas Instruments ADS7128 8-channel, 12-bit analog-to-digital converter with integrated GPIO and programmable window comparator.

• 8 Analog Input Channels: 12-bit resolution (0-4095) ADC
• Dual Operating Modes: Manual or autonomous conversion
• Configurable GPIO: Each pin can be analog input, digital input, or digital output
• Window Comparator: Programmable high/low thresholds with hysteresis
• Alert System: Trigger GPIO pins based on analog threshold events
• I2C Interface: Flexible addressing (0x10-0x17)x

• Chip: Texas Instruments ADS7128
• Resolution: 12-bit (4096 levels)
• Channels: 8 analog inputs (can be configured as GPIO)
• Interface: I2C (up to 400 kHz)
• Supply Voltage: 2.7V to 5.5V
• Reference Voltage: Internal or external (up to AVDD)

#include <Wire.h>
#include "ADS7128.h"

// Enable debug output (Must Serial.begin() before adc.begin())
#define ADS7128_DEBUG 1

ADS7128 adc(0x10);

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

  adc.begin();

  // Configure pin 7 as a digital input
  adc.setPinMode(7, PIN_MODE_DIGITAL_INPUT);
}

void loop() {
  bool state = adc.digitalRead(7);

  Serial.print("Pin 7: ");
  Serial.println(state ? "HIGH" : "LOW");

  delay(500);
}

#include <Wire.h>
#include "ADS7128.h"

// Enable debug output (Must Serial.begin() before adc.begin())
#define ADS7128_DEBUG 1

// Create ADS7128 instance (default I2C address: 0x10)
ADS7128 adc();

void setup() {
  Serial.begin(115200);
  Wire.begin();
  
  // Initialize the ADC
  if (!adc.begin()) {
    Serial.println("ADS7128 not found!");
    while(1);
  }
  
  // Configure pin 0 as analog input
  adc.setPinMode(0, PIN_MODE_ANALOG_INPUT);
  adc.adc.enableManualMode();
}

void loop() {
  // Read analog value on pin 0(0-4095)
  uint16_t value = adc.analogRead(0);
  
  // Read voltage on pin 0 (assuming 3.3V reference)
  float voltage = adc.analogReadVoltage(0, 3.3);
  
  Serial.print("Value: ");
  Serial.print(value);
  Serial.print(" | Voltage: ");
  Serial.print(voltage);
  Serial.println(" V");
  
  delay(1000);
}

• 1: This library currently uses a less efficient register update method. The ADS7128 includes the ability to set or clear individual bits of a register through specific register commands. This allows for less I2C commands to be issued, as the typical read-set-write register operations do not need to be performed.

• 2: The continuous register block read and write are also not implemented, meaning each result must be read individually.

• 3: Additional features of the ADS7128 are missing: RMS, CRC, sample rate selection, I2C mode, OSR and some aspects of the zero crossing module.

• 4: Scale analogRead delay with the configured OSR ratio, or poll conversion done register.

• 1: The analogRead function while in Manual mode uses a fixed delay (delayMicroseconds(10)), this means if conversion is not complete before reading, the data will be stale.

Constructor. Creates an ADS7128 instance.

• i2cAddr: I2C address (default: 0x10, range: 0x10-0x17)

Initialize the device. Returns true if successful.

• wirePort: I2C bus to use (default: Wire)

Configure a pin's operating mode.

• pin: Pin number (0-7)
• mode: PIN_MODE_ANALOG_INPUT, PIN_MODE_DIGITAL_INPUT, or PIN_MODE_DIGITAL_OUTPUT

Get the current pin mode.

Set output drive mode (for output pins only).

• mode: DRIVE_MODE_OPEN_DRAIN or DRIVE_MODE_PUSH_PULL

Read analog value from a channel (0-4095).

• channel: Channel number (0-7)

Read analog value as voltage.

• channel: Channel number (0-7)
• vref: Reference voltage in volts

Enable manual conversion mode. Conversions triggered on-demand.

• channels: Bit mask of channels to enable (e.g., 0x03 for channels 0 and 1)

Enable autonomous conversion mode. Continuous background conversions.

• channels: Bit mask of channels to enable

Write a digital value to an output pin.

• pin: Pin number (0-7)
• value: true (HIGH) or false (LOW)

Read a digital value from an input pin. Returns true (HIGH) or false (LOW).

Enable or disable window comparator functionality.

Configure window comparator thresholds for a channel.

• channel: Channel number (0-7)
• windowMax: Upper threshold voltage
• windowMin: Lower threshold voltage
• eventCount: Number of consecutive events before triggering (0-15)
• Vref: Reference voltage

Set hysteresis voltage to prevent threshold oscillation.

Define alert region (inside or outside window).

• regions: 0x00 for outside window, 0xFF for inside window

Configure alert pin behavior.

• drive: Drive mode (0 = open-drain, 1 = push-pull)
• logic: Logic configuration (0-3)

Select which channels can trigger alerts.

• channels: Bit mask of channels

Enable GPIO pins to be triggered by alerts.

• pins: Bit mask of pins

Map alert sources to a specific GPIO pin.

• pin: GPIO pin number (0-7)
• alerts: Bit mask of alert sources

Set the output value when a pin is triggered.

• pin: Pin number (0-7)
• state: Value to set on trigger

Get device status. Returns a SystemStatus struct with:

• bool sequenceActive: Conversion sequence active
• bool highSpeedI2C: High-speed I2C mode
• bool osrDone: Oversampling complete
• bool crcError: CRC error detected
• bool powerOnReset: Power-on reset occurred
• uint8_t rawValue: Raw status register value

Check if device is ready for operation.

Clear the power-on reset flag.

Perform a software reset.

Write to a register directly.

Read from a register directly.

See examples/ManualReadings/ManualReadings.ino

See examples/ManualReadings/ManualReadings.ino

See examples/ManualReadings/ManualReadings.ino

The ADS7128 I2C address is determined by the ADDR pin:

• Wire: Arduino I2C library (included with Arduino core)

This project is licensed under the MIT License - see the LICENSE file for details.

• ADS7128 Datasheet
• TI ADS7128 Product Page
• GitHub Repository