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RIOT/drivers/adcxx1c/adcxx1c.c 3.58 KB
a752c7ab   elopes   add first test an...
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  /*
   * Copyright (C) 2017 OTA keys S.A.
   *
   * This file is subject to the terms and conditions of the GNU Lesser
   * General Public License v2.1. See the file LICENSE in the top level
   * directory for more details.
   */
  
  /**
   * @ingroup     drivers_adcxx1x
   * @{
   *
   * @file
   * @brief       ADCXX1C ADC device driver
   *
   * @author      Vincent Dupont <vincent@otakeys.com>
   * @}
   */
  
  #include "adcxx1c.h"
  #include "adcxx1c_params.h"
  #include "adcxx1c_regs.h"
  
  #include "periph/i2c.h"
  #include "periph/gpio.h"
  
  #define ENABLE_DEBUG (0)
  #include "debug.h"
  
  #define I2C_SPEED I2C_SPEED_FAST
  
  #define I2C (dev->params.i2c)
  #define ADDR (dev->params.addr)
  
  /* Configuration register test value
   * value 0x20: cycle time = Tconvert x 64 */
  #define CONF_TEST_VALUE (0x20)
  
  int adcxx1c_init(adcxx1c_t *dev, const adcxx1c_params_t *params)
  {
      assert(dev && params);
  
      dev->params = *params;
      dev->cb = NULL;
  
      i2c_acquire(I2C);
      if (i2c_init_master(I2C, I2C_SPEED) < 0) {
          i2c_release(I2C);
          DEBUG("[adcxx1c] init - error: unable to initialize I2C bus\n");
          return ADCXX1C_NOI2C;
      }
  
      uint8_t reg = 0;
  
      /* Test communication write and read configuration register */
      i2c_write_reg(I2C, ADDR, ADCXX1C_CONF_ADDR, CONF_TEST_VALUE);
      i2c_read_reg(I2C, ADDR, ADCXX1C_CONF_ADDR, &reg);
  
      if (reg != CONF_TEST_VALUE) {
          i2c_release(I2C);
          DEBUG("[adcxx1c] init - error: unable to communicate with the device (reg=%x)\n", reg);
          return ADCXX1C_NODEV;
      }
  
      reg = dev->params.cycle << 5;
      i2c_write_reg(I2C, ADDR, ADCXX1C_CONF_ADDR, reg);
      i2c_release(I2C);
  
      adcxx1c_set_alert_parameters(dev, dev->params.low_limit,
                                   dev->params.high_limit,
                                   dev->params.hysteresis);
  
      return ADCXX1C_OK;
  }
  
  int adcxx1c_read_raw(const adcxx1c_t *dev, int16_t *raw)
  {
      uint8_t buf[2];
      int status;
  
      i2c_acquire(I2C);
      status = i2c_read_regs(I2C, ADDR, ADCXX1C_CONV_RES_ADDR, buf, 2);
      i2c_release(I2C);
      if (status < 2) {
          return ADCXX1C_NOI2C;
      }
  
      *raw = ((buf[0] & 0x0F) << 8 | buf[1]) >> (12 - dev->params.bits);
  
      return ADCXX1C_OK;
  }
  
  static void _alert_cb(void *arg)
  {
      adcxx1c_t *dev = arg;
  
      if (dev->cb) {
          dev->cb(dev->arg);
      }
  }
  
  int adcxx1c_enable_alert(adcxx1c_t *dev, adcxx1c_cb_t cb, void *arg)
  {
      uint8_t reg;
  
      i2c_acquire(I2C);
      i2c_read_reg(I2C, ADDR, ADCXX1C_CONF_ADDR, &reg);
      reg |= (dev->params.alert_pin != GPIO_UNDEF ? ADCXX1C_CONF_ALERT_PIN_EN : 0)
              | ADCXX1C_CONF_ALERT_FLAG_EN;
      i2c_write_reg(I2C, ADDR, ADCXX1C_CONF_ADDR, reg);
      i2c_release(I2C);
  
      if (dev->params.alert_pin != GPIO_UNDEF) {
          dev->cb = cb;
          dev->arg = arg;
          /* alert active low */
          gpio_init_int(dev->params.alert_pin, GPIO_IN, GPIO_FALLING, _alert_cb, dev);
      }
  
      return ADCXX1C_OK;
  }
  
  int adcxx1c_set_alert_parameters(const adcxx1c_t *dev, int16_t low_limit,
                                   int16_t high_limit, int16_t hysteresis)
  {
      uint8_t buf[2];
  
      i2c_acquire(I2C);
  
      low_limit <<= (12 - dev->params.bits);
      buf[0] = low_limit >> 8;
      buf[1] = low_limit & 0xFF;
      i2c_write_regs(I2C, ADDR, ADCXX1C_LOW_LIMIT_ADDR, buf, 2);
  
      high_limit <<= (12 - dev->params.bits);
      buf[0] = high_limit >> 8;
      buf[1] = high_limit & 0xFF;
      i2c_write_regs(I2C, ADDR, ADCXX1C_HIGH_LIMIT_ADDR, buf, 2);
  
      hysteresis <<= (12 - dev->params.bits);
      buf[0] = hysteresis >> 8;
      buf[1] = hysteresis & 0xFF;
      i2c_write_regs(I2C, ADDR, ADCXX1C_HYSTERESIS_ADDR, buf, 2);
  
      i2c_release(I2C);
  
      return ADCXX1C_OK;
  }