828F/applications/drv/drv_ads111x.c

/*
 * Copyright (c) 2025, Your Name
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2025-12-27     Developer    First version for ADS1115 on RT-Thread
 */

#include <rtthread.h>
#include <rtdevice.h>
#include <board.h>
#include "Variable.h"

#define DBG_TAG "sensor.ads1115"
#define DBG_LVL DBG_LOG
#include <rtdbg.h>

/* ADS1115 I2C 地址（A0 引脚接地时为 0x48） */
#define ADS1115_I2C_ADDR        0x48
/* 使用的 I2C 总线设备名 */
#define ADS1115_I2C_BUS_NAME    "i2c2"   // 根据你的板子修改，如 "i2c1"

/* ADS1115 寄存器地址 */
#define ADS1115_REG_CONVERT     0x00
#define ADS1115_REG_CONFIG      0x01

static struct rt_i2c_bus_device *i2c_bus = RT_NULL;

/**
 * 向 ADS1115 写入配置寄存器
 */
static rt_err_t ads1115_write_config(rt_uint16_t config)
{
    rt_uint8_t buf[3] = {
        ADS1115_REG_CONFIG,
        (rt_uint8_t)(config >> 8),
        (rt_uint8_t)(config & 0xFF)
    };

    struct rt_i2c_msg msgs[1] = {
        {
            .addr  = ADS1115_I2C_ADDR,
            .flags = RT_I2C_WR,
            .buf   = buf,
            .len   = 3,
        }
    };

    if (rt_i2c_transfer(i2c_bus, msgs, 1) != 1)
    {
        LOG_E("Failed to write config register.");
        return -RT_ERROR;
    }
    return RT_EOK;
}

/**
 * 从 ADS1115 读取转换结果
 */
static rt_err_t ads1115_read_conversion(rt_int16_t *value)
{
    rt_uint8_t buf[2] = {0};

    struct rt_i2c_msg msgs[2] = {
        {
            .addr  = ADS1115_I2C_ADDR,
            .flags = RT_I2C_WR,
            .buf   = (rt_uint8_t[]){ADS1115_REG_CONVERT},
            .len   = 1,
        },
        {
            .addr  = ADS1115_I2C_ADDR,
            .flags = RT_I2C_RD,
            .buf   = buf,
            .len   = 2,
        }
    };

    if (rt_i2c_transfer(i2c_bus, msgs, 2) != 2)
    {
        LOG_E("Failed to read conversion register.");
        return -RT_ERROR;
    }

    *value = (rt_int16_t)((buf[0] << 8) | buf[1]);
    return RT_EOK;
}

/**
 * 读取指定通道的 ADC 值（单端输入）
 * channel: 0 ~ 3 (对应 AIN0~AIN3 对 GND)
 * 返回：RT_EOK 或错误码
 */
static rt_err_t ads1115_read_channel(rt_uint8_t channel, rt_int16_t *raw_value)
{
    if (channel > 3)
    {
        LOG_E("Invalid channel: %d", channel);
        return -RT_EINVAL;
    }

    // 配置：OS=1, MUX=100+ch (单端), PGA=001 (±4.096V), MODE=1 (single), DR=100 (128SPS)
    rt_uint16_t config = 0x8000 |                     // OS = 1
                         ((0x04 | channel) << 12) |   // MUX: AINx vs GND
                         (0x01 << 9) |                // PGA = ±4.096V
                         (0x01 << 8) |                // MODE = single-shot
                         (0x04 << 5);                 // DR = 128 SPS

    if (ads1115_write_config(config) != RT_EOK)
    {
        return -RT_ERROR;
    }

    rt_thread_mdelay(10); // 等待转换完成（128SPS ≈ 8ms）

    return ads1115_read_conversion(raw_value);
}


/**
 * 将原始 ADC 值转换为毫伏（mV）
 * 假设使用 ±2.048V 量程（PGA=1），则 LSB = 2.048V / 32768 ≈ 0.0625 mV/LSB
 * 但因为是单端且参考地，实际范围 0~2.048V → 满量程 2.048V = 32768 LSB
 * 所以：Voltage(mV) = raw * (2048 / 32768) = raw * 0.0625
 */
static rt_int32_t ads1115_raw_to_mv(rt_int16_t raw)
{
    /* 注意：单端模式下，raw 应为正数（0 ~ 32767）*/
    return (rt_int32_t)(((rt_int64_t)raw * 125) / 1000); // 等价于 raw * 0.0625 * 1000
}

/**
 * ADS1115 读取线程（示例：读取 AIN0）
 */
static void ads1115_thread_entry(void *parameter)
{
    rt_int16_t raw = 0 ,mt = 900;

    while (1)
    {
        if(mt>900)
        {
            if (ads1115_read_channel(0, &raw) == RT_EOK)
            {
                pow_bat = ads1115_raw_to_mv(raw);
            }
            else
            {
                LOG_E("Failed to read ADS1115 P_BAT");
            }
        }
        else
        {
            mt = 0;
        }
        rt_thread_mdelay(1000);

        if (ads1115_read_channel(1, &raw) == RT_EOK)
        {
            pow_code = ads1115_raw_to_mv(raw);
        }
        else
        {
            LOG_E("Failed to read ADS1115 P_CODE");
        }
        rt_thread_mdelay(1000);

        if (ads1115_read_channel(2, &raw) == RT_EOK)
        {
            pow_dev1 = ads1115_raw_to_mv(raw);
        }
        else
        {
            LOG_E("Failed to read ADS1115 P_DEV1");
        }
        rt_thread_mdelay(1000);

        if (ads1115_read_channel(3, &raw) == RT_EOK)
        {
            pow_dev2 = ads1115_raw_to_mv(raw);
        }
        else
        {
            LOG_E("Failed to read ADS1115 P_DEV2");
        }
        rt_thread_mdelay(1000); // 每  秒读取一次
    }
}

/**
 * ADS1115 驱动初始化函数
 */
static int rt_hw_ads1115_init(void)
{
    i2c_bus = rt_i2c_bus_device_find(ADS1115_I2C_BUS_NAME);
    if (i2c_bus == RT_NULL)
    {
        LOG_E("Failed to find I2C bus: %s", ADS1115_I2C_BUS_NAME);
        return -RT_ENOSYS;
    }

    LOG_I("Found I2C bus: %s", ADS1115_I2C_BUS_NAME);

    /* 创建读取线程 */
    rt_thread_t tid = rt_thread_create("ads1115",
                                       ads1115_thread_entry,
                                       RT_NULL,
                                       512,
                                       RT_THREAD_PRIORITY_MAX - 2,
                                       10);
    if (tid != RT_NULL)
    {
        rt_thread_startup(tid);
    }
    else
    {
        LOG_E("Failed to create ADS1115 thread.");
        return -RT_ERROR;
    }

    return RT_EOK;
}

/* 自动初始化 */
INIT_APP_EXPORT(rt_hw_ads1115_init);