AD3530R no-OS Driver

See drivers/dac/ad3530r (doxygen) for the Doxygen documentation.

Supported Devices

AD3530R

AD3531R

AD3532R

Overview

The AD3530R/AD3531R/AD3532R are precision digital-to-analog converters (DACs) with multiple channels and 16-bit resolution. The AD3530R features 8 channels, AD3531R features 4 channels, and AD3532R features 16 channels. These devices support voltage output modes, making them versatile for driving various industrial loads. The devices support SPI communication with CRC error checking, hardware and software LDAC triggering, and multiple operating modes per channel. They include internal/external voltage reference options and flexible output ranges.

Device Configuration

Device Setup and Configuration

The ad3530r_init function initializes and configures the AD3530R/AD3531R/ AD3532R, involving memory allocation, SPI initialization, GPIO setup for RESET and LDAC pins, and comprehensive device configuration. The initialization process includes product ID verification, scratch pad testing, and configuration of operating modes, output ranges, reference selection, and CRC settings.

Resource Management

The ad3530r_remove function deallocates resources associated with the device, removing GPIO descriptors, SPI descriptor, and freeing allocated memory to ensure proper resource release and prevent memory leaks.

SPI Communication

The ad3530r_reg_read and ad3530r_reg_write functions handle SPI interactions for the device. These functions support both short and long instruction modes, CRC error checking, and streaming mode configurations.

Channel Configuration

Individual channels can be configured for different operating modes using ad3530r_set_operating_mode. Output ranges are set per channel group using ad3530r_set_output_range, allowing fine-tuned control of each DAC output.

DAC Value Setting

DAC values can be set using ad3530r_set_dac_value for individual channels or ad3530r_set_multidac_value for simultaneous updates across multiple channels. The driver supports different write modes for immediate updates or synchronized updates using LDAC triggers.

Hardware Features

The driver supports hardware LDAC triggering via GPIO pin using ad3530r_hw_ldac_trigger and software LDAC triggering using ad3530r_sw_ldac_trigger. Reference voltage can be configured as internal or external using ad3530r_set_reference. The MUX output selection allows monitoring of various signals using ad3530r_set_mux_out_select.

Driver Initialization Example

#include <stdint.h>
#include "no_os_delay.h"
#include "no_os_spi.h"
#include "no_os_gpio.h"
#include "ad3530r.h"

// Initialization parameters for the AD3530R device
struct ad3530r_init_param init_param = {
    .chip_id = AD3530R_ID, // Device Selection
    .spi_cfg = {
        .stream_mode_length = 0,
        .addr_asc = 0,
        .single_instr = 1,
        .short_instr = 0,
        .stream_length_keep_value = 0
    },
    .spi_param = &spi_init_param, // SPI configuration
    .reset_gpio_param_optional = &reset_gpio_param, // Optional reset GPIO
    .ldac_gpio_param_optional = &ldac_gpio_param,   // Optional LDAC GPIO
    .vref_enable = AD3530R_INTERNAL_VREF_PIN_2P5V,  // Internal 2.5V reference
    .chn_op_mode = {
        AD3530R_CH_OPERATING_MODE_0, // Channel 0
        AD3530R_CH_OPERATING_MODE_0, // Channel 1
        AD3530R_CH_OPERATING_MODE_0, // Channel 2
        AD3530R_CH_OPERATING_MODE_0, // Channel 3
        AD3530R_CH_OPERATING_MODE_0, // Channel 4
        AD3530R_CH_OPERATING_MODE_0, // Channel 5
        AD3530R_CH_OPERATING_MODE_0, // Channel 6
        AD3530R_CH_OPERATING_MODE_0  // Channel 7
    },
    .range = AD3530R_CH_OUTPUT_RANGE_0_VREF, // 0V to VREF range
    .hw_ldac_mask = 0x00, // No hardware LDAC enabled
    .sw_ldac_mask = 0xFF, // All channels software LDAC enabled
    .crc_en = 0,          // Disable CRC error checking
    .mux_out_sel = VOUT0  // Monitor channel 0 voltage output
};

// Device structure for the AD3530R
struct ad3530r_desc *ad3530r_device;

// Set up the AD3530R device
int32_t setup_ad3530r() {
    int32_t ret;
    uint16_t dac_value;

    // Initialize the device
    ret = ad3530r_init(&ad3530r_device, &init_param);
    if (ret) {
        printf("AD3530R initialization failed with error %d\n", ret);
        return ret;
    }

    // Configure channel 0 operating mode to normal mode
    ret = ad3530r_set_operating_mode(ad3530r_device, 0,
                                     AD3530R_CH_OPERATING_MODE_0);
    if (ret) {
        printf("Channel 0 configuration failed with error %d\n", ret);
        return ret;
    }

    // Set DAC value for channel 0 (mid-scale: 32768 for 16-bit)
    dac_value = 32768;
    ret = ad3530r_set_dac_value(ad3530r_device, dac_value, 0,
                                AD3530R_WRITE_DAC_REGS);
    if (ret) {
        printf("Setting DAC value failed with error %d\n", ret);
        return ret;
    }

    printf("AD3530R setup completed successfully\n");
    return 0;
}

// Example of multi-channel synchronized update
int32_t multi_channel_update() {
    int32_t ret;
    uint16_t dac_value = 40000; // Near full scale
    uint16_t channel_mask = 0x0F; // Channels 0-3

    // Set multiple channels simultaneously with LDAC trigger
    ret = ad3530r_set_multidac_value(ad3530r_device, dac_value,
                                     channel_mask,
                                     AD3530R_WRITE_INPUT_REGS_AND_TRIGGER_LDAC);
    if (ret) {
        printf("Multi-channel update failed with error %d\n", ret);
        return ret;
    }

    printf("Multi-channel update completed successfully\n");
    return 0;
}

// Main function for AD3530R demonstration
int main() {
    int32_t status;

    // Setup the device
    status = setup_ad3530r();
    if (status) {
        return status;
    }

    // Perform multi-channel update
    status = multi_channel_update();
    if (status) {
        return status;
    }

    // Clean up resources
    status = ad3530r_remove(ad3530r_device);
    if (status) {
        printf("Device cleanup failed with error %d\n", status);
        return status;
    }

    printf("AD3530R demonstration completed successfully\n");
    return 0;
}