ADS1220 Driver for ESP32

Multi-instance driver for the Texas Instruments ADS1220 24-bit ADC. Compatible with both ESP-IDF and Arduino IDE.

Features

• ✅ Multi-instance support - Control multiple ADS1220 devices on the same SPI bus
• ✅ Continuous data acquisition - Interrupt-driven reading with callbacks
• ✅ Preset configurations - Ready-to-use profiles for common applications
• ✅ Full register control - Direct access to all ADS1220 configuration registers
• ✅ Bit-field unions - Readable and type-safe register configuration
• ✅ Dual platform support - Works with ESP-IDF and Arduino IDE

Hardware Connections

ADS1220 Pin	ESP32 Pin	Description
SCLK	GPIO 18	SPI Clock (configurable)
DIN (MOSI)	GPIO 23	SPI MOSI (configurable)
DOUT (MISO)	GPIO 19	SPI MISO (configurable)
CS	GPIO 5	Chip Select (configurable, unique per device)
DRDY	GPIO 34	Data Ready interrupt (configurable, unique per device)
DVDD	3.3V	Digital supply voltage
AVDD	3.3V	Analog supply voltage
DGND	GND	Digital ground
AGND	GND	Analog ground

Installation

ESP-IDF

Method 1: Managed Component (Recommended)

Add the component as a dependency using the ESP-IDF Component Manager. This method automatically manages updates and dependencies.

1. Create or edit main/idf_component.yml in your project:

   dependencies:
     ads1220:
       git: https://github.com/yourusername/ADS1220.git
       version: ">=1.0.0"
   

2. Build your project:

   idf.py build
   

3. The component will be automatically downloaded to managed_components/ads1220/

4. Include in your code:

   #include "ads1220.h"
   

Alternative: Using a specific branch or commit:

dependencies:
  ads1220:
    git: https://github.com/yourusername/ADS1220.git
    path: "."
    version: main  # or a specific commit hash

Method 2: Manual Installation

1. Copy this repository to your project's components/ directory:

   your_project/
   ├── components/
   │   └── ADS1220/
   ├── main/
   └── CMakeLists.txt
   

2. The component will be automatically detected and linked by ESP-IDF

Arduino IDE

Method 1: Install from ZIP (Recommended)

1. Download the repository as a ZIP file:

   • Go to https://github.com/uclm-mantis/ads1220
   • Click the green Code button
   • Select Download ZIP

2. In Arduino IDE, go to Sketch → Include Library → Add .ZIP Library...

3. Select the downloaded ads1220-main.zip file

4. The library will be installed and appear in Sketch → Include Library → ADS1220

Method 2: Manual Installation

1. Copy this repository to your Arduino libraries directory:

   • Windows: Documents\Arduino\libraries\ADS1220\
   • macOS: ~/Documents/Arduino/libraries/ADS1220/
   • Linux: ~/Arduino/libraries/ADS1220/

2. Restart Arduino IDE

3. The library will appear in Sketch → Include Library → ADS1220

Quick Start

ESP-IDF Example

#include "ads1220.h"

void data_callback(int32_t raw_data) {
    printf("ADC: %ld\n", raw_data);
}

void app_main(void) {
    // Initialize SPI bus
    spi_bus_config_t bus_cfg = {
        .mosi_io_num = 23,
        .miso_io_num = 19,
        .sclk_io_num = 18,
        .quadwp_io_num = -1,
        .quadhd_io_num = -1,
    };
    spi_bus_initialize(SPI2_HOST, &bus_cfg, SPI_DMA_CH_AUTO);

    // Create ADS1220 device
    ADS1220_init_config_t init_cfg = {
        .spi_host = SPI2_HOST,
        .cs_pin = 5,
        .drdy_pin = 34,
        .spi_clock_speed_hz = 1000000,
    };
    ADS1220_t* adc = ads1220_create(&init_cfg);

    // Get preset configuration
    ADS1220_Config_t config;
    ads1220_get_preset_config(ADS1220_PRESET_LOAD_CELL, &config);
    
    // Write configuration
    ads1220_write_config(adc, &config);
    
    // Start continuous acquisition
    ads1220_start_continuous(adc, data_callback);
}

Arduino Example

#include <SPI.h>
#include "ads1220.h"

#define CS_PIN 5
#define DRDY_PIN 34

ADS1220_t* adc;

void dataCallback(int32_t raw_data) {
    Serial.print("ADC: ");
    Serial.println(raw_data);
}

void setup() {
    Serial.begin(115200);
    SPI.begin();
    
    ADS1220_init_config_t init_cfg = {
        .spi_host = SPI2_HOST,
        .cs_pin = CS_PIN,
        .drdy_pin = DRDY_PIN,
        .spi_clock_speed_hz = 1000000,
    };
    adc = ads1220_create(&init_cfg);
    
    ADS1220_Config_t config;
    ads1220_get_preset_config(ADS1220_PRESET_LOAD_CELL, &config);
    ads1220_write_config(adc, &config);
    ads1220_start_continuous(adc, dataCallback);
}

void loop() {
    // Data is handled in callback
    delay(1000);
}

API Reference

Device Management

ads1220_create()

Creates and initializes an ADS1220 device instance.

ADS1220_t* ads1220_create(const ADS1220_init_config_t* config);

Parameters:

• config - Initialization configuration (SPI host, CS pin, DRDY pin, clock speed)

Returns: Device handle or NULL on failure

---

ads1220_destroy()

Destroys an ADS1220 device instance and frees resources.

void ads1220_destroy(ads1220_t* dev);

---

Configuration

ads1220_get_preset_config()

Gets a preconfigured profile for common use cases.

esp_err_t ads1220_get_preset_config(ADS1220_Preset_t preset, ADS1220_Config_t *cfg);

Presets:

• ADS1220_PRESET_LOAD_CELL - Load cell: AIN0-1, G=128, DR=600, VREF external (REFP0/REFN0)
• ADS1220_PRESET_FERNANDO - Fernando's config: AIN0-1, G=64, DR=2000, VREF internal

---

ads1220_write_config()

Writes all 4 configuration registers to the ADS1220.

esp_err_t ads1220_write_config(ADS1220_t* dev, const ADS1220_Config_t *cfg);

---

ads1220_read_config()

Reads all 4 configuration registers from the ADS1220.

esp_err_t ads1220_read_config(ADS1220_t* dev, ADS1220_Config_t *out);

---

Data Acquisition

ads1220_read_data()

Reads the last conversion result (24-bit signed).

esp_err_t ads1220_read_data(ADS1220_t* dev, int32_t *data);

---

ads1220_start_continuous()

Starts continuous data acquisition triggered by DRDY interrupt.

esp_err_t ads1220_start_continuous(ADS1220_t* dev, ads1220_data_callback_t callback);

Parameters:

• callback - Function called when new data is ready: void callback(int32_t raw_data)

---

ads1220_stop_continuous()

Stops continuous data acquisition.

void ads1220_stop_continuous(ADS1220_t* dev);

---

Commands

ads1220_reset()

Resets the ADS1220 to default configuration.

esp_err_t ads1220_reset(ADS1220_t* dev);

---

ads1220_start()

Starts or restarts conversions.

esp_err_t ads1220_start(ADS1220_t* dev);

---

ads1220_powerdown()

Powers down the ADS1220 to save power.

esp_err_t ads1220_powerdown(ADS1220_t* dev);

---

Preset Configurations

Load Cell (ADS1220_PRESET_LOAD_CELL)

Optimized for load cell measurements with external reference voltage.

• Input: AIN0-1 (differential)
• Gain: 128
• Data Rate: 2000 SPS (Turbo mode)
• Reference: External (REFP0/REFN0)
• Mode: Continuous conversion

Fernando (ADS1220_PRESET_FERNANDO)

General-purpose configuration with internal reference.

• Input: AIN0-1 (differential)
• Gain: 64
• Data Rate: 2000 SPS (Turbo mode)
• Reference: Internal 2.048V
• Mode: Continuous conversion

Advanced Usage

Custom Configuration

You can create custom configurations by directly setting the bit-fields:

ADS1220_Config_t config = {
    .mux = ADS1220_MUX_AIN0_AIN1,
    .gain = ADS1220_GAIN_128,
    .pga_bypass = 0,
    .dr = ADS1220_DR_TURBO_2000SPS,
    .mode = ADS1220_MODE_TURBO,
    .cm = 1,  // Continuous conversion
    .vref = ADS1220_VREF_REFP0_REFN0,
    .fir = ADS1220_FIR_OFF,
    .idac = ADS1220_IDAC_OFF,
    // ... other fields
};

ads1220_write_config(adc, &config);

Multiple Devices

// Device 1
ADS1220_init_config_t cfg1 = {
    .spi_host = SPI2_HOST,
    .cs_pin = 5,
    .drdy_pin = 34,
    .spi_clock_speed_hz = 1000000,
};
ADS1220_t* adc1 = ads1220_create(&cfg1);

// Device 2 (same SPI bus, different CS and DRDY)
ADS1220_init_config_t cfg2 = {
    .spi_host = SPI2_HOST,
    .cs_pin = 15,
    .drdy_pin = 35,
    .spi_clock_speed_hz = 1000000,
};
ADS1220_t* adc2 = ads1220_create(&cfg2);

Troubleshooting

Problem: No data received

• Check SPI connections (MOSI, MISO, SCLK, CS)
• Verify DRDY pin is connected and configured correctly
• Ensure power supply is stable (3.3V)

Problem: Noisy readings

• Use proper grounding
• Add decoupling capacitors near ADS1220 (0.1µF + 10µF)
• Keep analog and digital grounds separate, connect at single point
• Use shielded cables for analog inputs

Problem: Build errors in Arduino IDE

• Ensure library is in correct folder
• Restart Arduino IDE after installation
• Check that ESP32 board support is installed

License

MIT License - see LICENSE file for details

Contributors

• Francisco Moya Fernández
• Fernando Castillo García
• Antonio González Rodríguez
• David Rodríguez Rosa
• Sergio Juárez Pérez
• Andrea Martín Parra
• Raúl Cuadros Tardío
• Juan Sánchez Medina

References

• ADS1220 Datasheet
• ESP-IDF SPI Master Driver