/* * Driver for barometic pressure sensor MS5611-01BA03 * * Copyright (C) 2016 Bernhard Guillon * * Loosely based on hmc5831 with: * Copyright (C) 2016 Ruslan V. Uss * BSD Licensed as described in the file LICENSE */ #include "ms561101ba03.h" #include #include #include "FreeRTOS.h" #include "task.h" #define CONVERT_D1 0x40 #define CONVERT_D2 0x50 #define ADC_READ 0x00 #define RESET 0x1E /* * FIXME: * The chip has different response times for the different oversampling rates * (0.5 ms/1.1ms/2.1ms/4.1ms/8.22ms) * For now use a save value. */ #define CONVERSION_TIME 20 / portTICK_PERIOD_MS // milliseconds static inline bool reset(uint8_t addr) { uint8_t buf[1] = { RESET }; return i2c_slave_write(addr, buf, 1); } static inline bool read_prom(ms561101ba03_t *dev) { uint8_t tmp[2] = { 0, 0 }; if (!i2c_slave_read(dev->addr, 0xA2, tmp, 2)) return false; dev->config_data.sens = tmp[0] << 8 | tmp[1]; if (!i2c_slave_read(dev->addr, 0xA4, tmp, 2)) return false; dev->config_data.off = tmp[0] << 8 | tmp[1]; if (!i2c_slave_read(dev->addr, 0xA6, tmp, 2)) return false; dev->config_data.tcs = tmp[0] << 8 | tmp[1]; if (!i2c_slave_read(dev->addr, 0xA8, tmp, 2)) return false; dev->config_data.tco = tmp[0] << 8 | tmp[1]; if (!i2c_slave_read(dev->addr, 0xAA, tmp, 2)) return false; dev->config_data.t_ref = tmp[0] << 8 | tmp[1]; if (!i2c_slave_read(dev->addr, 0xAC, tmp, 2)) return false; dev->config_data.tempsens = tmp[0] << 8 | tmp[1]; return true; } static inline bool start_pressure_conversion(ms561101ba03_t *dev) //D1 { uint8_t buf = CONVERT_D1 + dev->osr; return i2c_slave_write(dev->addr, &buf, 1); } static inline bool start_temperature_conversion(ms561101ba03_t *dev) //D2 { uint8_t buf = CONVERT_D2 + dev->osr; return i2c_slave_write(dev->addr, &buf, 1); } static inline bool read_adc(uint8_t addr, uint32_t *result) { *result = 0; uint8_t tmp[3]; if (!i2c_slave_read(addr, 0x00, tmp, 3)) return false; *result = (tmp[0] << 16) | (tmp[1] << 8) | tmp[2]; // If we are to fast the ADC will return 0 instead of the actual result if (*result == 0) return false; return true; } static inline void calc_dt(ms561101ba03_t *dev, uint32_t digital_temperature) { // Difference between actual and reference digital_temperature // dT = D2 - T_ref = D2 - C5 *2^8 dev->dT = digital_temperature - ((int32_t)dev->config_data.t_ref << 8); } static inline int32_t calc_temp(ms561101ba03_t *dev) { // Actual temerature (-40...85C with 0.01 resulution) // TEMP = 20C +dT * TEMPSENSE =2000 + dT * C6 / 2^23 return (int32_t)(2000 + (int64_t)dev->dT * dev->config_data.tempsens / 8388608); } static inline int64_t calc_off(ms561101ba03_t *dev) { // Offset at actual temperature // OFF=OFF_t1 + TCO * dT = OFF_t1(C2) * 2^16 + (C4*dT)/2^7 return (int64_t)((int64_t)dev->config_data.off * (int64_t)65536) + (((int64_t)dev->config_data.tco * (int64_t)dev->dT) / (int64_t)128); } static inline int64_t calc_sens(ms561101ba03_t *dev) { // Senisitivity at actual temperature // SENS=SENS_t1 + TCS *dT = SENS_t1(C1) *2^15 + (TCS(C3) *dT)/2^8 return (int64_t)(((int64_t)dev->config_data.sens) * (int64_t)32768) + (((int64_t)dev->config_data.tcs * (int64_t)dev->dT) / (int64_t)256); } static inline int32_t calc_p(uint32_t digital_pressure, int64_t sens, int64_t off) { // Temperature compensated pressure (10...1200mbar with 0.01mbar resolution // P = digital pressure value * SENS - OFF = (D1 * SENS/2^21 -OFF)/2^15 return (int32_t)(((int64_t)digital_pressure * (int64_t)((int64_t)sens / (int64_t)0x200000) - (int64_t)off) / (int64_t)32768); } static inline bool get_raw_temperature(ms561101ba03_t *dev, uint32_t *result) { if (!start_temperature_conversion(dev)) return false; vTaskDelay(CONVERSION_TIME); if (!read_adc(dev->addr, result)) return false; return true; } static inline bool get_raw_pressure(ms561101ba03_t *dev, uint32_t *result) { if (!start_pressure_conversion(dev)) return false; vTaskDelay(CONVERSION_TIME); if (!read_adc(dev->addr, result)) return false; return true; } /////////////////////////Public////////////////////////////////////// bool ms561101ba03_get_sensor_data(ms561101ba03_t *dev) { // Second order temperature compensation see datasheet p8 uint32_t raw_pressure = 0; if (!get_raw_pressure(dev, &raw_pressure)) return false; uint32_t raw_temperature = 0; if (!get_raw_temperature(dev, &raw_temperature)) return false; calc_dt(dev, raw_temperature); int64_t temp = calc_temp(dev); int64_t off = calc_off(dev); int64_t sens = calc_sens(dev); //Set defaults for temp >= 2000 int64_t t_2 = 0; int64_t off_2 = 0; int64_t sens_2 = 0; int64_t help = 0; if (temp < 2000) { //Low temperature t_2 = ((dev->dT * dev->dT) >> 31); // T2 = dT^2/2^31 help = (temp - 2000); help = 5 * help * help; off_2 = help >> 1; // OFF_2 = 5 * (TEMP - 2000)^2/2^1 sens_2 = help >> 2; // SENS_2 = 5 * (TEMP - 2000)^2/2^2 if (temp < -1500) { // Very low temperature help = (temp + 1500); help = help * help; off_2 = off_2 + 7 * help; // OFF_2 = OFF_2 + 7 * (TEMP + 1500)^2 sens_2 = sens_2 + ((11 * help) >> 1); // SENS_2 = SENS_2 + 7 * (TEMP + 1500)^2/2^1 } } temp = temp - t_2; off = off - off_2; sens = sens - sens_2; dev->result.pressure = calc_p(raw_pressure, sens, off); dev->result.temperature = (int32_t)temp; return true; } bool ms561101ba03_init(ms561101ba03_t *dev) { // First of all we need to reset the chip if (!reset(dev->addr)) return false; // Wait a bit for the device to reset vTaskDelay(CONVERSION_TIME); // Get the config if (!read_prom(dev)) return false; // Every thing went fine return true; }