esp-open-rtos/extras/bmp180/bmp180.c
2017-10-28 22:57:22 +05:00

356 lines
11 KiB
C

#include "bmp180.h"
#include "FreeRTOS.h"
#include "queue.h"
#include "task.h"
#include "espressif/esp_common.h"
#include "espressif/sdk_private.h"
#define BMP180_RX_QUEUE_SIZE 10
#define BMP180_TASK_PRIORITY 9
#define BMP180_VERSION_REG 0xD0
#define BMP180_CONTROL_REG 0xF4
#define BMP180_RESET_REG 0xE0
#define BMP180_OUT_MSB_REG 0xF6
#define BMP180_OUT_LSB_REG 0xF7
#define BMP180_OUT_XLSB_REG 0xF8
#define BMP180_CALIBRATION_REG 0xAA
//
// Values for BMP180_CONTROL_REG
//
#define BMP180_MEASURE_TEMP 0x2E
#define BMP180_MEASURE_PRESS 0x34
//
// CHIP ID stored in BMP180_VERSION_REG
//
#define BMP180_CHIP_ID 0x55
//
// Reset value for BMP180_RESET_REG
//
#define BMP180_RESET_VALUE 0xB6
static int bmp180_readRegister16(i2c_dev_t *dev, uint8_t reg, int16_t *r)
{
uint8_t d[] = { 0, 0 };
int error;
if ((error = i2c_slave_read(dev->bus, dev->addr, &reg, d, 2)))
return error;
*r = ((int16_t)d[0] << 8) | (d[1]);
return 0;
}
static int bmp180_start_Messurement(i2c_dev_t *dev, uint8_t cmd)
{
uint8_t reg = BMP180_CONTROL_REG;
return i2c_slave_write(dev->bus, dev->addr, &reg, &cmd, 1);
}
static bool bmp180_get_uncompensated_temperature(i2c_dev_t *dev, int32_t *ut)
{
// Write Start Code into reg 0xF4.
if (bmp180_start_Messurement(dev, BMP180_MEASURE_TEMP))
return false;
// Wait 5ms, datasheet states 4.5ms
sdk_os_delay_us(5000);
int16_t v;
if (bmp180_readRegister16(dev, BMP180_OUT_MSB_REG, &v))
return false;
*ut = v;
return true;
}
static bool bmp180_get_uncompensated_pressure(i2c_dev_t *dev, uint8_t oss, uint32_t *up)
{
uint16_t us;
// Limit oss and set the measurement wait time. The datasheet
// states 4.5, 7.5, 13.5, 25.5ms for oss 0 to 3.
switch (oss) {
case 0: us = 5000; break;
case 1: us = 8000; break;
case 2: us = 14000; break;
default: oss = 3; us = 26000; break;
}
// Write Start Code into reg 0xF4
if (bmp180_start_Messurement(dev, BMP180_MEASURE_PRESS | (oss << 6)))
return false;
sdk_os_delay_us(us);
uint8_t d[] = { 0, 0, 0 };
uint8_t reg = BMP180_OUT_MSB_REG;
if (i2c_slave_read(dev->bus, dev->addr, &reg, d, 3))
return false;
uint32_t r = ((uint32_t)d[0] << 16) | ((uint32_t)d[1] << 8) | d[2];
r >>= 8 - oss;
*up = r;
return true;
}
// Returns true of success else false.
bool bmp180_fillInternalConstants(i2c_dev_t *dev, bmp180_constants_t *c)
{
if (bmp180_readRegister16(dev, BMP180_CALIBRATION_REG+0, &c->AC1) ||
bmp180_readRegister16(dev, BMP180_CALIBRATION_REG+2, &c->AC2) ||
bmp180_readRegister16(dev, BMP180_CALIBRATION_REG+4, &c->AC3) ||
bmp180_readRegister16(dev, BMP180_CALIBRATION_REG+6, (int16_t *)&c->AC4) ||
bmp180_readRegister16(dev, BMP180_CALIBRATION_REG+8, (int16_t *)&c->AC5) ||
bmp180_readRegister16(dev, BMP180_CALIBRATION_REG+10, (int16_t *)&c->AC6) ||
bmp180_readRegister16(dev, BMP180_CALIBRATION_REG+12, &c->B1) ||
bmp180_readRegister16(dev, BMP180_CALIBRATION_REG+14, &c->B2) ||
bmp180_readRegister16(dev, BMP180_CALIBRATION_REG+16, &c->MB) ||
bmp180_readRegister16(dev, BMP180_CALIBRATION_REG+18, &c->MC) ||
bmp180_readRegister16(dev, BMP180_CALIBRATION_REG+20, &c->MD)) {
return false;
}
#ifdef BMP180_DEBUG
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);
printf("%s: B1:=%d B2:=%d\n", __FUNCTION__, c->B1, c->B2);
printf("%s: MB:=%d MC:=%d MD:=%d\n", __FUNCTION__, c->MB, c->MC, c->MD);
#endif
// Error if any read as 0x0000 or 0xffff.
return !(c->AC1 == 0x0000 || c->AC2 == 0x0000 || c->AC3 == 0x0000 ||
c->AC4 == 0x0000 || c->AC5 == 0x0000 || c->AC6 == 0x0000 ||
c->B1 == 0x0000 || c->B2 == 0x0000 ||
c->MB == 0x0000 || c->MC == 0x0000 || c->MD == 0x0000 ||
c->AC1 == 0xffff || c->AC2 == 0xffff || c->AC3 == 0xffff ||
c->AC4 == 0xffff || c->AC5 == 0xffff || c->AC6 == 0xffff ||
c->B1 == 0xffff || c->B2 == 0xffff ||
c->MB == 0xffff || c->MC == 0xffff || c->MD == 0xffff);
}
bool bmp180_is_available(i2c_dev_t *dev)
{
uint8_t id;
uint8_t reg = BMP180_VERSION_REG;
if (i2c_slave_read(dev->bus, dev->addr, &reg, &id, 1))
return false;
return id == BMP180_CHIP_ID;
}
bool bmp180_measure(i2c_dev_t *dev, bmp180_constants_t *c, int32_t *temperature,
uint32_t *pressure, uint8_t oss)
{
int32_t T, P;
if (!temperature && !pressure)
return false;
// Temperature is always needed, also required for pressure only.
//
// Calculation taken from BMP180 Datasheet
int32_t UT, X1, X2, B5;
if (!bmp180_get_uncompensated_temperature(dev, &UT))
return false;
X1 = ((UT - (int32_t)c->AC6) * (int32_t)c->AC5) >> 15;
X2 = ((int32_t)c->MC << 11) / (X1 + (int32_t)c->MD);
B5 = X1 + X2;
T = (B5 + 8) >> 4;
if (temperature)
*temperature = T;
#ifdef BMP180_DEBUG
printf("%s: T:= %ld.%d\n", __FUNCTION__, T/10, abs(T%10));
#endif
if (pressure) {
int32_t X3, B3, B6;
uint32_t B4, B7, UP;
if (!bmp180_get_uncompensated_pressure(dev, oss, &UP))
return false;
// Calculation taken from BMP180 Datasheet
B6 = B5 - 4000;
X1 = ((int32_t)c->B2 * ((B6 * B6) >> 12)) >> 11;
X2 = ((int32_t)c->AC2 * B6) >> 11;
X3 = X1 + X2;
B3 = ((((int32_t)c->AC1 * 4 + X3) << oss) + 2) >> 2;
X1 = ((int32_t)c->AC3 * B6) >> 13;
X2 = ((int32_t)c->B1 * ((B6 * B6) >> 12)) >> 16;
X3 = ((X1 + X2) + 2) >> 2;
B4 = ((uint32_t)c->AC4 * (uint32_t)(X3 + 32768)) >> 15;
B7 = ((uint32_t)UP - B3) * (uint32_t)(50000UL >> oss);
if (B7 < 0x80000000UL) {
P = (B7 * 2) / B4;
} else {
P = (B7 / B4) * 2;
}
X1 = (P >> 8) * (P >> 8);
X1 = (X1 * 3038) >> 16;
X2 = (-7357 * P) >> 16;
P = P + ((X1 + X2 + (int32_t)3791) >> 4);
if (pressure)
*pressure = P;
#ifdef BMP180_DEBUG
printf("%s: P:= %ld\n", __FUNCTION__, P);
#endif
}
return true;
}
// BMP180_Event_Command
typedef struct
{
uint8_t cmd;
const QueueHandle_t* resultQueue;
} bmp180_command_t;
// Just works due to the fact that QueueHandle_t is a "void *"
static QueueHandle_t bmp180_rx_queue[I2C_MAX_BUS] = { NULL };
static TaskHandle_t bmp180_task_handle[I2C_MAX_BUS] = { NULL };
//
// Forward declarations
//
static bool bmp180_informUser_Impl(const QueueHandle_t* resultQueue, uint8_t cmd, bmp180_temp_t temperature, bmp180_press_t pressure);
// Set default implementation .. User gets result as bmp180_result_t event
bool (*bmp180_informUser)(const QueueHandle_t* resultQueue, uint8_t cmd, bmp180_temp_t temperature, bmp180_press_t pressure) = bmp180_informUser_Impl;
// I2C Driver Task
static void bmp180_driver_task(void *pvParameters)
{
// Data to be received from user
bmp180_command_t current_command;
bmp180_constants_t bmp180_constants;
i2c_dev_t *dev = (i2c_dev_t*)pvParameters;
#ifdef BMP180_DEBUG
// Wait for commands from the outside
printf("%s: Started Task\n", __FUNCTION__);
#endif
// Initialize all internal constants.
if (!bmp180_fillInternalConstants(dev, &bmp180_constants)) {
printf("%s: reading internal constants failed\n", __FUNCTION__);
vTaskDelete(NULL);
}
while(1) {
// Wait for user to insert commands
if (xQueueReceive(bmp180_rx_queue[dev->bus], &current_command, portMAX_DELAY) == pdTRUE) {
#ifdef BMP180_DEBUG
printf("%s: Received user command %d 0x%p\n", __FUNCTION__, current_command.cmd, current_command.resultQueue);
#endif
// use user provided queue
if (current_command.resultQueue != NULL) {
// Work on it ...
int32_t T = 0;
uint32_t P = 0;
if (bmp180_measure(dev, &bmp180_constants, &T, (current_command.cmd & BMP180_PRESSURE) ? &P : NULL, 3)) {
// Inform the user ...
if (!bmp180_informUser(current_command.resultQueue,
current_command.cmd,
((bmp180_temp_t)T)/10.0,
(bmp180_press_t)P)) {
// Failed to send info to user
printf("%s: Unable to inform user bmp180_informUser returned \"false\"\n", __FUNCTION__);
}
}
}
}
}
}
static bool bmp180_create_communication_queues(i2c_dev_t *dev)
{
// Just create them once by bus
if (bmp180_rx_queue[dev->bus] == NULL)
bmp180_rx_queue[dev->bus] = xQueueCreate(BMP180_RX_QUEUE_SIZE, sizeof(bmp180_result_t));
return bmp180_rx_queue[dev->bus] != NULL;
}
static bool bmp180_createTask(i2c_dev_t *dev)
{
// We already have a task
portBASE_TYPE x = pdPASS;
if (bmp180_task_handle[dev->bus] == NULL) {
x = xTaskCreate(bmp180_driver_task, "bmp180_driver_task", 256, (void*)dev, BMP180_TASK_PRIORITY, &bmp180_task_handle[dev->bus]); //TODO: name task with i2c bus
}
return x == pdPASS;
}
// Default user inform implementation
static bool bmp180_informUser_Impl(const QueueHandle_t* resultQueue, uint8_t cmd, bmp180_temp_t temperature, bmp180_press_t pressure)
{
bmp180_result_t result;
result.cmd = cmd;
result.temperature = temperature;
result.pressure = pressure;
return (xQueueSend(*resultQueue, &result, 0) == pdTRUE);
}
// Just init all needed queues
bool bmp180_init(i2c_dev_t *dev)
{
// 1. Create required queues
bool result = false;
if (bmp180_create_communication_queues(dev)) {
// 2. Check for bmp180 ...
if (bmp180_is_available(dev)) {
// 3. Start driver task
if (bmp180_createTask(dev)) {
// We are finished
result = true;
}
}
}
return result;
}
void bmp180_trigger_measurement(i2c_dev_t *dev, const QueueHandle_t* resultQueue)
{
bmp180_command_t c;
c.cmd = BMP180_PRESSURE + BMP180_TEMPERATURE;
c.resultQueue = resultQueue;
xQueueSend(bmp180_rx_queue[dev->bus], &c, 0);
}
void bmp180_trigger_pressure_measurement(i2c_dev_t *dev, const QueueHandle_t* resultQueue)
{
bmp180_command_t c;
c.cmd = BMP180_PRESSURE;
c.resultQueue = resultQueue;
xQueueSend(bmp180_rx_queue[dev->bus], &c, 0);
}
void bmp180_trigger_temperature_measurement(i2c_dev_t *dev, const QueueHandle_t* resultQueue)
{
bmp180_command_t c;
c.cmd = BMP180_TEMPERATURE;
c.resultQueue = resultQueue;
xQueueSend(bmp180_rx_queue[dev->bus], &c, 0);
}