bmp180: make a lower level interface available and support oversampling.
An application using multiple I2C devices will need it's own loop. This reworks the code to make the detection, calibration constant loading, and measurment functions available too without having to use the bmp810 task which is still retained. Adds support for oversampling. Fixes a bug in the calculation of the temperature. Better error handling. Checks for I2C errors and errors in the loading of the calibration constants and propagates these up.
This commit is contained in:
ourairquality
parent
6915caf49c
commit
05bbe48bd4
3 changed files with 190 additions and 155 deletions
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@ -73,7 +73,7 @@ void bmp180_task(void *pvParameters)
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bmp180_trigger_measurement(com_queue);
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break;
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case MY_EVT_BMP180:
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printf("%s: Received BMP180 Event temp:=%d.%d°C press=%d.%02dhPa\n", __FUNCTION__, \
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printf("%s: Received BMP180 Event temp:=%d.%dC press=%d.%02dhPa\n", __FUNCTION__, \
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(int32_t)ev.bmp180_data.temperature, abs((int32_t)(ev.bmp180_data.temperature*10)%10), \
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ev.bmp180_data.pressure/100, ev.bmp180_data.pressure%100 );
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break;
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@ -27,12 +27,7 @@
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// Values for BMP180_CONTROL_REG
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//
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#define BMP180_MEASURE_TEMP 0x2E
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#define BMP180_MEASURE_PRESS_OSS0 0x34
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#define BMP180_MEASURE_PRESS_OSS1 0x74
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#define BMP180_MEASURE_PRESS_OSS2 0xB4
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#define BMP180_MEASURE_PRESS_OSS3 0xF4
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#define BMP180_DEFAULT_CONV_TIME 5000
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#define BMP180_MEASURE_PRESS 0x34
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//
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// CHIP ID stored in BMP180_VERSION_REG
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@ -56,25 +51,9 @@ typedef struct
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static xQueueHandle bmp180_rx_queue = NULL;
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static xTaskHandle bmp180_task_handle = NULL;
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// Calibration constants
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static int16_t AC1;
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static int16_t AC2;
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static int16_t AC3;
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static uint16_t AC4;
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static uint16_t AC5;
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static uint16_t AC6;
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static int16_t B1;
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static int16_t B2;
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static int16_t MB;
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static int16_t MC;
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static int16_t MD;
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//
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// Forward declarations
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//
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static void bmp180_meassure(const bmp180_command_t* command);
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static bool bmp180_informUser_Impl(const xQueueHandle* resultQueue, uint8_t cmd, bmp180_temp_t temperature, bmp180_press_t pressure);
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// Set default implementation .. User gets result as bmp180_result_t event
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@ -85,109 +64,158 @@ static void bmp180_driver_task(void *pvParameters)
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{
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// Data to be received from user
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bmp180_command_t current_command;
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bmp180_constants_t bmp180_constants;
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#ifdef BMP180_DEBUG
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// Wait for commands from the outside
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printf("%s: Started Task\n", __FUNCTION__);
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#endif
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while(1)
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{
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// Initialize all internal constants.
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if (!bmp180_fillInternalConstants(&bmp180_constants)) {
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printf("%s: reading internal constants failed\n", __FUNCTION__);
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vTaskDelete(NULL);
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}
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while(1) {
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// Wait for user to insert commands
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if (xQueueReceive(bmp180_rx_queue, ¤t_command, portMAX_DELAY) == pdTRUE)
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{
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if (xQueueReceive(bmp180_rx_queue, ¤t_command, portMAX_DELAY) == pdTRUE) {
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#ifdef BMP180_DEBUG
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printf("%s: Received user command %d 0x%p\n", __FUNCTION__, current_command.cmd, current_command.resultQueue);
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#endif
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// use user provided queue
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if (current_command.resultQueue != NULL)
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{
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if (current_command.resultQueue != NULL) {
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// Work on it ...
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bmp180_meassure(¤t_command);
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int32_t T = 0;
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uint32_t P = 0;
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if (bmp180_measure(&bmp180_constants, &T, (current_command.cmd & BMP180_PRESSURE) ? &P : NULL, 3)) {
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// Inform the user ...
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if (!bmp180_informUser(current_command.resultQueue,
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current_command.cmd,
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((bmp180_temp_t)T)/10.0,
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(bmp180_press_t)P)) {
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// Failed to send info to user
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printf("%s: Unable to inform user bmp180_informUser returned \"false\"\n", __FUNCTION__);
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}
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}
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}
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}
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}
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}
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static uint8_t bmp180_readRegister8(uint8_t reg)
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{
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uint8_t r = 0;
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if (!i2c_slave_read(BMP180_DEVICE_ADDRESS, reg, &r, 1))
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{
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r = 0;
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}
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return r;
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}
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static int16_t bmp180_readRegister16(uint8_t reg)
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static bool bmp180_readRegister16(uint8_t reg, int16_t *r)
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{
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uint8_t d[] = { 0, 0 };
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int16_t r = 0;
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if (i2c_slave_read(BMP180_DEVICE_ADDRESS, reg, d, 2))
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{
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r = ((int16_t)d[0]<<8) | (d[1]);
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}
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return r;
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if (!i2c_slave_read(BMP180_DEVICE_ADDRESS, reg, d, 2))
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return false;
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*r = ((int16_t)d[0] << 8) | (d[1]);
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return true;
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}
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static void bmp180_start_Messurement(uint8_t cmd)
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static bool bmp180_start_Messurement(uint8_t cmd)
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{
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uint8_t d[] = { BMP180_CONTROL_REG, cmd };
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i2c_slave_write(BMP180_DEVICE_ADDRESS, d, 2);
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return i2c_slave_write(BMP180_DEVICE_ADDRESS, d, 2);
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}
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static int16_t bmp180_getUncompensatedMessurement(uint8_t cmd)
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static bool bmp180_get_uncompensated_temperature(int32_t *ut)
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{
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// Write Start Code into reg 0xF4 (Currently without oversampling ...)
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bmp180_start_Messurement((cmd==BMP180_TEMPERATURE)?BMP180_MEASURE_TEMP:BMP180_MEASURE_PRESS_OSS0);
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// Write Start Code into reg 0xF4.
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if (!bmp180_start_Messurement(BMP180_MEASURE_TEMP))
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return false;
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// Wait 5ms Datasheet states 4.5ms
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sdk_os_delay_us(BMP180_DEFAULT_CONV_TIME);
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// Wait 5ms, datasheet states 4.5ms
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sdk_os_delay_us(5000);
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return (int16_t)bmp180_readRegister16(BMP180_OUT_MSB_REG);
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int16_t v;
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if (!bmp180_readRegister16(BMP180_OUT_MSB_REG, &v))
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return false;
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*ut = v;
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return true;
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}
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static void bmp180_fillInternalConstants(void)
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static bool bmp180_get_uncompensated_pressure(uint8_t oss, uint32_t *up)
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{
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AC1 = bmp180_readRegister16(BMP180_CALIBRATION_REG+0);
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AC2 = bmp180_readRegister16(BMP180_CALIBRATION_REG+2);
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AC3 = bmp180_readRegister16(BMP180_CALIBRATION_REG+4);
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AC4 = bmp180_readRegister16(BMP180_CALIBRATION_REG+6);
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AC5 = bmp180_readRegister16(BMP180_CALIBRATION_REG+8);
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AC6 = bmp180_readRegister16(BMP180_CALIBRATION_REG+10);
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uint16_t us;
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B1 = bmp180_readRegister16(BMP180_CALIBRATION_REG+12);
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B2 = bmp180_readRegister16(BMP180_CALIBRATION_REG+14);
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// Limit oss and set the measurement wait time. The datasheet
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// states 4.5, 7.5, 13.5, 25.5ms for oss 0 to 3.
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switch (oss) {
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case 0: us = 5000; break;
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case 1: us = 8000; break;
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case 2: us = 14000; break;
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default: oss = 3; us = 26000; break;
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}
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MB = bmp180_readRegister16(BMP180_CALIBRATION_REG+16);
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MC = bmp180_readRegister16(BMP180_CALIBRATION_REG+18);
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MD = bmp180_readRegister16(BMP180_CALIBRATION_REG+20);
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// Write Start Code into reg 0xF4
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if (!bmp180_start_Messurement(BMP180_MEASURE_PRESS | (oss << 6)))
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return false;
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sdk_os_delay_us(us);
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uint8_t d[] = { 0, 0, 0 };
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if (!i2c_slave_read(BMP180_DEVICE_ADDRESS, BMP180_OUT_MSB_REG, d, 3))
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return false;
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uint32_t r = ((uint32_t)d[0] << 16) | ((uint32_t)d[1] << 8) | d[2];
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r >>= 8 - oss;
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*up = r;
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return true;
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}
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// Returns true of success else false.
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bool bmp180_fillInternalConstants(bmp180_constants_t *c)
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{
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if (!bmp180_readRegister16(BMP180_CALIBRATION_REG+0, &c->AC1) ||
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!bmp180_readRegister16(BMP180_CALIBRATION_REG+2, &c->AC2) ||
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!bmp180_readRegister16(BMP180_CALIBRATION_REG+4, &c->AC3) ||
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!bmp180_readRegister16(BMP180_CALIBRATION_REG+6, (int16_t *)&c->AC4) ||
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!bmp180_readRegister16(BMP180_CALIBRATION_REG+8, (int16_t *)&c->AC5) ||
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!bmp180_readRegister16(BMP180_CALIBRATION_REG+10, (int16_t *)&c->AC6) ||
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!bmp180_readRegister16(BMP180_CALIBRATION_REG+12, &c->B1) ||
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!bmp180_readRegister16(BMP180_CALIBRATION_REG+14, &c->B2) ||
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!bmp180_readRegister16(BMP180_CALIBRATION_REG+16, &c->MB) ||
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!bmp180_readRegister16(BMP180_CALIBRATION_REG+18, &c->MC) ||
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!bmp180_readRegister16(BMP180_CALIBRATION_REG+20, &c->MD)) {
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return false;
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}
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#ifdef BMP180_DEBUG
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printf("%s: AC1:=%d AC2:=%d AC3:=%d AC4:=%u AC5:=%u AC6:=%u \n", __FUNCTION__, AC1, AC2, AC3, AC4, AC5, AC6);
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printf("%s: B1:=%d B2:=%d\n", __FUNCTION__, B1, B2);
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printf("%s: MB:=%d MC:=%d MD:=%d\n", __FUNCTION__, MB, MC, MD);
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printf("%s: AC1:=%d AC2:=%d AC3:=%d AC4:=%u AC5:=%u AC6:=%u \n", __FUNCTION__, c->AC1, c->AC2, c->AC3, c->AC4, c->AC5, c->AC6);
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printf("%s: B1:=%d B2:=%d\n", __FUNCTION__, c->B1, c->B2);
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printf("%s: MB:=%d MC:=%d MD:=%d\n", __FUNCTION__, c->MB, c->MC, c->MD);
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#endif
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// Error if any read as 0x0000 or 0xffff.
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return !(c->AC1 == 0x0000 || c->AC2 == 0x0000 || c->AC3 == 0x0000 ||
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c->AC4 == 0x0000 || c->AC5 == 0x0000 || c->AC6 == 0x0000 ||
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c->B1 == 0x0000 || c->B2 == 0x0000 ||
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c->MB == 0x0000 || c->MC == 0x0000 || c->MD == 0x0000 ||
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c->AC1 == 0xffff || c->AC2 == 0xffff || c->AC3 == 0xffff ||
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c->AC4 == 0xffff || c->AC5 == 0xffff || c->AC6 == 0xffff ||
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c->B1 == 0xffff || c->B2 == 0xffff ||
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c->MB == 0xffff || c->MC == 0xffff || c->MD == 0xffff);
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}
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static bool bmp180_create_communication_queues()
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{
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// Just create them once
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if (bmp180_rx_queue==NULL)
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{
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if (bmp180_rx_queue == NULL)
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bmp180_rx_queue = xQueueCreate(BMP180_RX_QUEUE_SIZE, sizeof(bmp180_result_t));
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}
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return (bmp180_rx_queue!=NULL);
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return bmp180_rx_queue != NULL;
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}
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static bool bmp180_is_avaialble()
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bool bmp180_is_available()
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{
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return (bmp180_readRegister8(BMP180_VERSION_REG)==BMP180_CHIP_ID);
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uint8_t id;
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return i2c_slave_read(BMP180_DEVICE_ADDRESS, BMP180_VERSION_REG, &id, 1) &&
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id == BMP180_CHIP_ID;
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}
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static bool bmp180_createTask()
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@ -195,87 +223,74 @@ static bool bmp180_createTask()
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// We already have a task
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portBASE_TYPE x = pdPASS;
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if (bmp180_task_handle==NULL)
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{
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if (bmp180_task_handle == NULL) {
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x = xTaskCreate(bmp180_driver_task, (signed char *)"bmp180_driver_task", 256, NULL, BMP180_TASK_PRIORITY, &bmp180_task_handle);
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}
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return (x==pdPASS);
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return x == pdPASS;
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}
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static void bmp180_meassure(const bmp180_command_t* command)
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bool bmp180_measure(bmp180_constants_t *c, int32_t *temperature,
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uint32_t *pressure, uint8_t oss)
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{
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int32_t T, P;
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// Init result to 0
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T = P = 0;
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if (!temperature && !pressure)
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return false;
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if (command->resultQueue != NULL)
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{
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int32_t UT, X1, X2, B5;
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// Temperature is always needed, allso required for pressure only.
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//
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// Calculation taken from BMP180 Datasheet
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int32_t UT, X1, X2, B5;
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if (!bmp180_get_uncompensated_temperature(&UT))
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return false;
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X1 = ((UT - (int32_t)c->AC6) * (int32_t)c->AC5) >> 15;
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X2 = ((int32_t)c->MC << 11) / (X1 + (int32_t)c->MD);
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B5 = X1 + X2;
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T = (B5 + 8) >> 4;
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if (temperature)
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*temperature = T;
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#ifdef BMP180_DEBUG
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printf("%s: T:= %ld.%d\n", __FUNCTION__, T/10, abs(T%10));
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#endif
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if (pressure) {
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int32_t X3, B3, B6;
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uint32_t B4, B7, UP;
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if (!bmp180_get_uncompensated_pressure(oss, &UP))
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return false;
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//
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// Temperature is always needed ... Also required for pressure only
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//
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// Calculation taken from BMP180 Datasheet
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UT = (int32_t)bmp180_getUncompensatedMessurement(BMP180_TEMPERATURE);
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B6 = B5 - 4000;
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X1 = ((int32_t)c->B2 * ((B6 * B6) >> 12)) >> 11;
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X2 = ((int32_t)c->AC2 * B6) >> 11;
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X3 = X1 + X2;
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X1 = (UT - (int32_t)AC6) * ((int32_t)AC5) >> 15;
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X2 = ((int32_t)MC << 11) / (X1 + (int32_t)MD);
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B5 = X1 + X2;
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B3 = ((((int32_t)c->AC1 * 4 + X3) << oss) + 2) >> 2;
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X1 = ((int32_t)c->AC3 * B6) >> 13;
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X2 = ((int32_t)c->B1 * ((B6 * B6) >> 12)) >> 16;
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X3 = ((X1 + X2) + 2) >> 2;
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B4 = ((uint32_t)c->AC4 * (uint32_t)(X3 + 32768)) >> 15;
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B7 = ((uint32_t)UP - B3) * (uint32_t)(50000UL >> oss);
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T = (B5 + 8) >> 4;
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#ifdef BMP180_DEBUG
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printf("%s: T:= %ld.%d\n", __FUNCTION__, T/10, abs(T%10));
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#endif
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// Do we also need pressure?
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if (command->cmd & BMP180_PRESSURE)
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{
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int32_t X3, B3, B6;
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uint32_t B4, B7, UP;
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UP = ((uint32_t)bmp180_getUncompensatedMessurement(BMP180_PRESSURE) & 0xFFFF);
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// Calculation taken from BMP180 Datasheet
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B6 = B5 - 4000;
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X1 = ((int32_t)B2 * ((B6 * B6) >> 12)) >> 11;
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X2 = ((int32_t)AC2 * B6) >> 11;
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X3 = X1 + X2;
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B3 = (((int32_t)AC1 * 4 + X3) + 2) >> 2;
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X1 = ((int32_t)AC3 * B6) >> 13;
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X2 = ((int32_t)B1 * ((B6 * B6) >> 12)) >> 16;
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X3 = ((X1 + X2) + 2) >> 2;
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B4 = ((uint32_t)AC4 * (uint32_t)(X3 + 32768)) >> 15;
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B7 = (UP - B3) * (uint32_t)(50000UL);
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if (B7 < 0x80000000)
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{
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P = (B7 * 2) / B4;
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}
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else
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{
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P = (B7 / B4) * 2;
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}
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X1 = (P >> 8) * (P >> 8);
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X1 = (X1 * 3038) >> 16;
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X2 = (-7357 * P) >> 16;
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P = P + ((X1 + X2 + (int32_t)3791) >> 4);
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#ifdef BMP180_DEBUG
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printf("%s: P:= %ld\n", __FUNCTION__, P);
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#endif
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if (B7 < 0x80000000UL) {
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P = (B7 * 2) / B4;
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} else {
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P = (B7 / B4) * 2;
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}
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// Inform the user ...
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if (!bmp180_informUser(command->resultQueue, command->cmd, ((bmp180_temp_t)T)/10.0, (bmp180_press_t)P))
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{
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// Failed to send info to user
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printf("%s: Unable to inform user bmp180_informUser returned \"false\"\n", __FUNCTION__);
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}
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X1 = (P >> 8) * (P >> 8);
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X1 = (X1 * 3038) >> 16;
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X2 = (-7357 * P) >> 16;
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P = P + ((X1 + X2 + (int32_t)3791) >> 4);
|
||||
if (pressure)
|
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*pressure = P;
|
||||
#ifdef BMP180_DEBUG
|
||||
printf("%s: P:= %ld\n", __FUNCTION__, P);
|
||||
#endif
|
||||
}
|
||||
return true;
|
||||
}
|
||||
|
||||
// Default user inform implementation
|
||||
|
|
@ -296,20 +311,13 @@ bool bmp180_init(uint8_t scl, uint8_t sda)
|
|||
// 1. Create required queues
|
||||
bool result = false;
|
||||
|
||||
if (bmp180_create_communication_queues())
|
||||
{
|
||||
if (bmp180_create_communication_queues()) {
|
||||
// 2. Init i2c driver
|
||||
i2c_init(scl, sda);
|
||||
|
||||
// 3. Check for bmp180 ...
|
||||
if (bmp180_is_avaialble())
|
||||
{
|
||||
// 4. Init all internal constants ...
|
||||
bmp180_fillInternalConstants();
|
||||
|
||||
// 5. Start driver task
|
||||
if (bmp180_createTask())
|
||||
{
|
||||
if (bmp180_is_available()) {
|
||||
// 4. Start driver task
|
||||
if (bmp180_createTask()) {
|
||||
// We are finished
|
||||
result = true;
|
||||
}
|
||||
|
|
|
|||
|
|
@ -52,4 +52,31 @@ void bmp180_trigger_pressure_measurement(const xQueueHandle* resultQueue);
|
|||
// Give the user the chance to create it's own handler
|
||||
extern bool (*bmp180_informUser)(const xQueueHandle* resultQueue, uint8_t cmd, bmp180_temp_t temperature, bmp180_press_t pressure);
|
||||
|
||||
// Calibration constants
|
||||
typedef struct
|
||||
{
|
||||
int16_t AC1;
|
||||
int16_t AC2;
|
||||
int16_t AC3;
|
||||
uint16_t AC4;
|
||||
uint16_t AC5;
|
||||
uint16_t AC6;
|
||||
|
||||
int16_t B1;
|
||||
int16_t B2;
|
||||
|
||||
int16_t MB;
|
||||
int16_t MC;
|
||||
int16_t MD;
|
||||
} bmp180_constants_t;
|
||||
|
||||
// Returns true if the bmp180 is detected.
|
||||
bool bmp180_is_available();
|
||||
// Reads all the internal constants, returning true on success.
|
||||
bool bmp180_fillInternalConstants(bmp180_constants_t *c);
|
||||
// Reads an optional temperature and pressure. The over sampling
|
||||
// setting, oss, may be 0 to 3. Returns true on success.
|
||||
bool bmp180_measure(bmp180_constants_t *c, int32_t *temperature,
|
||||
uint32_t *pressure, uint8_t oss);
|
||||
|
||||
#endif /* DRIVER_BMP180_H_ */
|
||||
|
|
|
|||
Loading…
Reference in a new issue