feat(gml670-v2): 添加二进制协议定义与 ADS1256 SPI 驱动

- protocol.h: CoP/Encoder/Resistance/Spotter/Heartbeat 帧定义,
  GML670 50kg ADC→kg 标定参数
- ads1256: SPI 命令模式驱动,BUFEN=1 解决高阻抗负载误差,
  3750 SPS 平衡精度与采样率,SELFCAL + 寄存器回读校验

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
This commit is contained in:
2026-04-30 17:39:05 +08:00
parent 5492a98687
commit 97f0d65783
3 changed files with 375 additions and 0 deletions
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#pragma once
#include <stdint.h>
/* sensor.c 切换通道时需要此寄存器地址 */
#define ADS1256_REG_MUX 0x01
/**
* @brief 初始化 ADS1256:配置 GPIO/SPI,复位芯片,写入寄存器,自校准。
* @return 0 成功,负 errno 失败。
*/
int ads1256_init(void);
/**
* @brief 等待 DRDY 拉低(转换结果可读),带超时保护。
* @param timeout_ms 超时时间(毫秒)。
*/
void ads1256_wait_drdy(uint16_t timeout_ms);
/**
* @brief 向 ADS1256 写单个寄存器。
* @param reg 目标寄存器地址。
* @param val 要写入的值。
*/
void ads1256_write_reg(uint8_t reg, uint8_t val);
/**
* @brief 从 ADS1256 读单个寄存器。
* @param reg 目标寄存器地址。
* @return 寄存器值。
*/
uint8_t ads1256_read_reg(uint8_t reg);
/**
* @brief 发送 SYNC + WAKEUP 命令,触发一次同步采样。
*/
void ads1256_sync_wakeup(void);
/**
* @brief 硬件复位 ADS1256(通过 RESET 引脚),等待复位后自校准完成。
*/
void ads1256_hwreset(void);
/**
* @brief 读取当前 24 位转换结果,符号扩展为 int32_t。
* @return ADC 原始值。
*/
int32_t ads1256_read_data(void);
/**
* @brief 发送单字节命令到 ADS1256。
* @param cmd 命令字。
*/
void ads1256_write_cmd(uint8_t cmd);
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#pragma once
#include <stdbool.h>
#include <stdint.h>
/* ─── 帧常量 ─── */
/* 双帧头比单字节魔数更容易在连续字节流里完成包起始判定。 */
#define PROTO_SYNC0 0xAAU
#define PROTO_SYNC1 0x55U
#define PROTO_TYPE_COP 0x01U /* 上行: 压力中心 (CoP) 帧 */
#define PROTO_TYPE_ENCODER 0x02U /* 上行: 电机编码器帧(预留) */
#define PROTO_TYPE_RESISTANCE 0x10U /* 下行: 阻力参数 (K, B, Tau) */
#define PROTO_TYPE_SPOTTER 0x11U /* 下行: Spotter Mode 保护阈值 */
#define PROTO_TYPE_HEARTBEAT 0x20U /* 下行: 心跳包 */
/* CoP flags 位定义 */
#define COP_FLAG_FORCE_VALID 0x01U /* 总力 > 阈值,CoP 坐标有意义 */
/* ─── 板面几何 & 传感器标定 ─── */
/* 传感器到板面中心的半宽、半长 (mm)。 */
#define BOARD_HALF_WIDTH_MM 100.0f
#define BOARD_HALF_LENGTH_MM 100.0f
/*
* ADC → kg 换算推导:
* GML670 50kg: 灵敏度 1.75 mV/V, 激励 5V → 满量程输出 8.75 mV
* ADS1256: PGA=64, VREF=2.5V → 满量程 ±78.125 mV
* 50kg 对应 ADC counts = 8.75 / 78.125 × 8388607 ≈ 939524
* 1 LSB = 50.0 / 939524 ≈ 5.322e-5 kg
* 如实际激励电压或 VREF 不同,按比例修正此系数。
*/
#define SENSOR_EXCITATION_V 5.0f
#define SENSOR_SENSITIVITY_MVV 1.75f
#define SENSOR_RATED_LOAD_KG 50.0f
#define ADS1256_VREF_V 2.5f
#define ADS1256_PGA 64
#define ADC_COUNTS_AT_RATED \
((SENSOR_SENSITIVITY_MVV * SENSOR_EXCITATION_V) / (2.0f * ADS1256_VREF_V * 1000.0f / ADS1256_PGA) * 8388607.0f)
#define ADC_TO_FORCE_SCALE (SENSOR_RATED_LOAD_KG / ADC_COUNTS_AT_RATED)
/* 总重低于此值时 CoP 无意义(除零保护),单位 kg */
#define COP_MIN_FORCE_THRESHOLD 0.5f
/* ─── 上行: CoP 帧 (17 bytes, 50 Hz) ───
*
* [AA 55 01 seq flags cop_x(4) cop_y(4) force(4)]
*/
struct cop_frame_t {
uint8_t sync0; /* = PROTO_SYNC0 */
uint8_t sync1; /* = PROTO_SYNC1 */
uint8_t type; /* = PROTO_TYPE_COP */
uint8_t seq; /* 包序号 0-255 滚动,用于丢包检测 */
uint8_t flags; /* bit0: force_valid */
float cop_x; /* 压力中心 X (mm),板面坐标系 */
float cop_y; /* 压力中心 Y (mm),板面坐标系 */
float force; /* 总重量 (kg) */
} __attribute__((packed));
union cop_pkt_t {
struct cop_frame_t frame;
uint8_t bytes[sizeof(struct cop_frame_t)];
};
/* ─── 上行: 电机编码器帧 (13 bytes, 预留) ───
*
* [AA 55 02 seq flags cable_length(4) velocity(4)]
*/
struct encoder_frame_t {
uint8_t sync0; /* = PROTO_SYNC0 */
uint8_t sync1; /* = PROTO_SYNC1 */
uint8_t type; /* = PROTO_TYPE_ENCODER */
uint8_t seq; /* 包序号 */
uint8_t flags; /* 预留,填 0 */
float cable_length; /* 拉索长度 (mm) */
float velocity; /* 拉索速度 (mm/s) */
} __attribute__((packed));
union encoder_pkt_t {
struct encoder_frame_t frame;
uint8_t bytes[sizeof(struct encoder_frame_t)];
};
/* ─── 下行: 阻力参数帧 (15 bytes) ───
*
* [AA 55 10 K(4) B(4) Tau(4)]
*/
struct resistance_frame_t {
uint8_t sync0; /* = PROTO_SYNC0 */
uint8_t sync1; /* = PROTO_SYNC1 */
uint8_t type; /* = PROTO_TYPE_RESISTANCE */
float K; /* 刚度 (N/m) */
float B; /* 阻尼 (Ns/m) */
float Tau; /* 时间常数 (s) */
} __attribute__((packed));
union resistance_pkt_t {
struct resistance_frame_t frame;
uint8_t bytes[sizeof(struct resistance_frame_t)];
};
/* ─── 下行: Spotter Mode 帧 (8 bytes) ───
*
* [AA 55 11 threshold(4) enable]
*/
struct spotter_frame_t {
uint8_t sync0; /* = PROTO_SYNC0 */
uint8_t sync1; /* = PROTO_SYNC1 */
uint8_t type; /* = PROTO_TYPE_SPOTTER */
float threshold; /* 保护力阈值 (N) */
uint8_t enable; /* 0 = 关闭, 1 = 启用 */
} __attribute__((packed));
union spotter_pkt_t {
struct spotter_frame_t frame;
uint8_t bytes[sizeof(struct spotter_frame_t)];
};
/* ─── 下行: 心跳帧 (4 bytes, ~1 Hz) ───
*
* [AA 55 20 counter]
*/
struct heartbeat_frame_t {
uint8_t sync0; /* = PROTO_SYNC0 */
uint8_t sync1; /* = PROTO_SYNC1 */
uint8_t type; /* = PROTO_TYPE_HEARTBEAT */
uint8_t counter; /* 滚动计数,用于活性检测 */
} __attribute__((packed));
union heartbeat_pkt_t {
struct heartbeat_frame_t frame;
uint8_t bytes[sizeof(struct heartbeat_frame_t)];
};
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#include "ads1256.h"
#include <stdint.h>
#include <zephyr/drivers/gpio.h>
#include <zephyr/drivers/spi.h>
#include <zephyr/kernel.h>
#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(ads1256, LOG_LEVEL_INF);
/* --- ADS1256 命令 --- */
#define CMD_WAKEUP 0x00
#define CMD_RDATA 0x01
#define CMD_RREG 0x10
#define CMD_WREG 0x50
#define CMD_SELFCAL 0xF0
#define CMD_SYNC 0xFC
#define CMD_SDATAC 0x0F
/* --- ADS1256 寄存器地址 --- */
#define REG_STATUS 0x00
#define REG_MUX 0x01
#define REG_ADCON 0x02
#define REG_DRATE 0x03
#define SPI_OP (SPI_OP_MODE_MASTER | SPI_MODE_CPHA | SPI_WORD_SET(8) | SPI_LINES_SINGLE)
/* --- 硬件资源 --- */
static const struct device *spi_dev;
static struct spi_config spi_cfg;
static const struct gpio_dt_spec cs_spec = GPIO_DT_SPEC_GET(DT_ALIAS(ads_cs), gpios);
static const struct gpio_dt_spec drdy_spec = GPIO_DT_SPEC_GET(DT_ALIAS(ads_drdy), gpios);
static const struct gpio_dt_spec reset_spec = GPIO_DT_SPEC_GET(DT_ALIAS(ads_reset), gpios);
void ads1256_wait_drdy(uint16_t timeout_ms) {
/* drdy_spec 配了 GPIO_ACTIVE_LOW,逻辑 1 表示 DRDY 有效(物理拉低) */
/* 用 k_usleep 代替 k_busy_wait,让出 CPU 给其他线程 */
int64_t deadline = k_uptime_get() + timeout_ms;
while (gpio_pin_get_dt(&drdy_spec) == 0) {
k_usleep(10);
if (k_uptime_get() >= deadline) {
LOG_WRN("DRDY timeout (%u ms)", timeout_ms);
break;
}
}
}
void ads1256_write_reg(uint8_t reg, uint8_t val) {
ads1256_wait_drdy(50);
gpio_pin_set_dt(&cs_spec, 1);
uint8_t tx_buf[3] = { CMD_WREG | reg, 0x00, val };
struct spi_buf tx = { .buf = tx_buf, .len = 3 };
struct spi_buf_set tx_set = { .buffers = &tx, .count = 1 };
spi_write(spi_dev, &spi_cfg, &tx_set);
gpio_pin_set_dt(&cs_spec, 0);
/* t11: WREG 后至少 4 × tCLKIN ≈ 0.5µs */
k_busy_wait(2);
}
uint8_t ads1256_read_reg(uint8_t reg) {
ads1256_wait_drdy(50);
gpio_pin_set_dt(&cs_spec, 1);
uint8_t tx_buf[2] = { CMD_RREG | reg, 0x00 };
struct spi_buf tx = { .buf = tx_buf, .len = 2 };
struct spi_buf_set tx_set = { .buffers = &tx, .count = 1 };
spi_write(spi_dev, &spi_cfg, &tx_set);
/* t6: RREG 后至少 50 × tCLKIN ≈ 6.5µs */
k_busy_wait(10);
uint8_t rx_val = 0;
struct spi_buf rx = { .buf = &rx_val, .len = 1 };
struct spi_buf_set rx_set = { .buffers = &rx, .count = 1 };
spi_read(spi_dev, &spi_cfg, &rx_set);
gpio_pin_set_dt(&cs_spec, 0);
return rx_val;
}
void ads1256_write_cmd(uint8_t cmd) {
ads1256_wait_drdy(50);
gpio_pin_set_dt(&cs_spec, 1);
struct spi_buf tx = { .buf = &cmd, .len = 1 };
struct spi_buf_set tx_set = { .buffers = &tx, .count = 1 };
spi_write(spi_dev, &spi_cfg, &tx_set);
gpio_pin_set_dt(&cs_spec, 0);
}
void ads1256_sync_wakeup(void) {
uint8_t cmd_sync = CMD_SYNC;
uint8_t cmd_wakeup = CMD_WAKEUP;
struct spi_buf tx_s = { .buf = &cmd_sync, .len = 1 };
struct spi_buf tx_w = { .buf = &cmd_wakeup, .len = 1 };
struct spi_buf_set set_s = { .buffers = &tx_s, .count = 1 };
struct spi_buf_set set_w = { .buffers = &tx_w, .count = 1 };
gpio_pin_set_dt(&cs_spec, 1);
spi_write(spi_dev, &spi_cfg, &set_s);
/* t11: SYNC 后至少 24 × tCLKIN ≈ 3.1µs */
k_busy_wait(4);
spi_write(spi_dev, &spi_cfg, &set_w);
gpio_pin_set_dt(&cs_spec, 0);
}
void ads1256_hwreset(void) {
/* reset_spec 配了 GPIO_ACTIVE_LOW:逻辑 1 = 物理 LOW = 断言复位 */
gpio_pin_set_dt(&reset_spec, 1);
/* t16: 最小复位脉宽 4 × tCLKIN ≈ 0.5µs,取 1ms 余量 */
k_msleep(10);
gpio_pin_set_dt(&reset_spec, 0);
/* 复位释放后芯片执行自校准,等待完成 */
k_msleep(10);
ads1256_wait_drdy(500);
}
int32_t ads1256_read_data(void) {
uint8_t cmd = CMD_RDATA;
uint8_t rx_buf[3] = { 0 };
gpio_pin_set_dt(&cs_spec, 1);
struct spi_buf tx = { .buf = &cmd, .len = 1 };
struct spi_buf_set tx_set = { .buffers = &tx, .count = 1 };
spi_write(spi_dev, &spi_cfg, &tx_set);
/* t6: RDATA 后至少 50 × tCLKIN ≈ 6.5µs */
k_busy_wait(10);
struct spi_buf rx = { .buf = rx_buf, .len = 3 };
struct spi_buf_set rx_set = { .buffers = &rx, .count = 1 };
spi_read(spi_dev, &spi_cfg, &rx_set);
gpio_pin_set_dt(&cs_spec, 0);
int32_t val = ((int32_t)rx_buf[0] << 16) | ((int32_t)rx_buf[1] << 8) | rx_buf[2];
if (val & 0x800000) val |= 0xFF000000;
return val;
}
int ads1256_init(void) {
/* GPIO */
gpio_pin_configure_dt(&cs_spec, GPIO_OUTPUT_INACTIVE);
gpio_pin_configure_dt(&reset_spec, GPIO_OUTPUT_INACTIVE);
gpio_pin_configure_dt(&drdy_spec, GPIO_INPUT);
/* SPI */
spi_dev = DEVICE_DT_GET(DT_NODELABEL(spi1));
spi_cfg.operation = SPI_OP;
spi_cfg.frequency = 500000;
spi_cfg.slave = 0;
if (!device_is_ready(spi_dev)) {
LOG_ERR("SPI device not ready");
return -ENODEV;
}
ads1256_hwreset();
/* 关闭连续输出模式,进入命令模式 */
ads1256_write_cmd(CMD_SDATAC);
k_busy_wait(100);
/*
* STATUS = 0x06: ORDER=MSB, ACAL=1(自动校准), BUFEN=1(开启输入缓冲)
* GML670 50kg 传感器输出阻抗 1kΩ,Buffer OFF + PGA=64 时输入阻抗仅 ~8kΩ
* (datasheet Table 10),导致 ~11% 负载误差。开 Buffer 后输入阻抗 >10MΩ。
*/
ads1256_write_reg(REG_STATUS, 0x06);
ads1256_write_reg(REG_MUX, 0x01);
/* ADCON: CLK_OUT=OFF, SDCS=OFF, PGA=64 */
ads1256_write_reg(REG_ADCON, 0x07);
/*
* DRATE: 3750 SPS (0xC0)
* 50Hz 循环 = 20ms 预算。4 通道各采 10 次均值:
* 单通道 = t18(0.44ms) + 9 × 1/3750(0.27ms) = 2.87ms
* 4 通道 = 11.5ms,余量 8.5ms
* 相比 30kSPS: ENOB 从 16.5 → 17.4 bit (Buffer On, PGA=64)
*/
ads1256_write_reg(REG_DRATE, 0xC0);
/* 显式自校准:Buffer/PGA 变更后必须重新校准 (datasheet p25) */
ads1256_write_cmd(CMD_SELFCAL);
/* SELFCAL 完成后 DRDY 拉低 (datasheet: "Do not send additional commands
after issuing this command until DRDY goes low") */
ads1256_wait_drdy(500);
/* 回读关键寄存器验证 SPI 通信正确性 */
uint8_t status = ads1256_read_reg(REG_STATUS);
uint8_t adcon = ads1256_read_reg(REG_ADCON);
uint8_t drate = ads1256_read_reg(REG_DRATE);
LOG_INF("ADS1256 regs: STATUS=0x%02X ADCON=0x%02X DRATE=0x%02X", status, adcon, drate);
if (drate != 0xC0) {
LOG_ERR("ADS1256 register verify failed (DRATE=0x%02X, expected 0xC0)", drate);
return -EIO;
}
LOG_INF("ADS1256 initialized (BUFEN=1, PGA=64, 3750SPS)");
return 0;
}