I've been trying to write a I2C device driver for the BMP 180 barometer and temperature sensor found on the E310 (as seen in sheet 9 of the schematic.) I have been basing my code off of the example driver given by bosch.
The driver requires function pointers to block read and write, as well as a sleep, which are basically the only original code:
int8_t user_i2c_read(uint8_t dev_id, uint8_t reg_addr,uint8_t *data, uint16_t len)
int8_t user_i2c_write(uint8_t dev_id, uint8_t reg_addr,uint8_t *data, uint16_t len)
void user_delay_ms(uint32_t period)
The problem I am having is that this driver (as well as simpler SMBUS command only programs I have written) have always failed to read or write the i2c address 0x77, where the sensor should be located on the bus.
readBytes for device ID 0x77: -1 - No such device or address
Even though my code seems to work for locations that other devices are located at (though I haven't done more than ping them)
Motion Sensor:
readBytes for device ID 0x69: 0 - Success
Temperature Sensor:
readBytes for device ID 0x19: 0 - Success
I was wondering either what is wrong with my code that the device would be completely unresponsive, or what hardware configuration am I missing that would explain the lack of communication with the barometer at 0x77.
I notice that the BMP-180 barometer is placed on the auxiliary i2c of the Gyro MPU-9150, but the wiring and datasheet make me think it is in pass through mode and not master mode. Just a thought I had though.
Here is all of the code I have that interacts with the bmpDriver.
Compiled with the following
gcc test.c -o test -std=c11 -D _DEFAULT_SOURCE
#include "bmp280.c"
#include <linux/i2c-dev-user.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
int8_t user_i2c_read(uint8_t dev_id, uint8_t reg_addr,uint8_t *data, uint16_t len){
int file;
file = open("/dev/i2c-0", O_RDWR);
if(file < 0)
{
printf("Failed to open /dev/i2c-0\n");
close(file);
return -1;
}
if(ioctl(file, I2C_SLAVE, dev_id) < 0)
{
printf("ioctl failed for /dev/i2c-0 at %x - %s\n", dev_id, strerror(errno));
close(file);
return -2;
}
int readBytes;
readBytes = i2c_smbus_read_block_data(file, reg_addr, data);
printf("readBytes for device ID 0x%x: %d - %s\n", dev_id, readBytes, strerror(errno));
close(file);
return readBytes;
}
int8_t user_i2c_write(uint8_t dev_id, uint8_t reg_addr,uint8_t *data, uint16_t len){
int file;
file = open("/dev/i2c-0", O_RDWR);
if(file < 0)
{
printf("Failed to open /dev/i2c-0\n");
close(file);
return -1;
}
if(ioctl(file, I2C_SLAVE, dev_id) < 0)
{
printf("ioctl failed for /dev/i2c-0 at %x - %s\n", dev_id, strerror(errno));
close(file);
return -2;
}
int writeBytes;
uint8_t shortLen = len;
writeBytes = i2c_smbus_write_block_data(file, reg_addr, shortLen, data);
printf("writeBytes for device ID 0x%x: %d - %s\n", dev_id, writeBytes, strerror(errno));
close(file);
return writeBytes;
}
void user_delay_ms(uint32_t period){
unsigned int sleep = period;
usleep(sleep * 1000);
}
int main(){
int8_t rslt;
struct bmp280_dev user_bmp;
user_bmp.dev_id = BMP280_I2C_ADDR_SEC;
user_bmp.intf = BMP280_I2C_INTF;
user_bmp.read = user_i2c_read;
user_bmp.write = user_i2c_write;
user_bmp.delay_ms = user_delay_ms;
rslt = bmp280_init(&user_bmp);
if (rslt == BMP280_OK) {
printf("Device found with chip id 0x%x\n", user_bmp.chip_id);
}
else {
printf("Device not found, exiting...\n");
return -1;
}
struct bmp280_config conf;
rslt = bmp280_get_config(&conf, &user_bmp);
conf.filter = BMP280_FILTER_COEFF_2;
conf.os_pres = BMP280_OS_16X;
conf.os_temp = BMP280_OS_4X;
conf.odr = BMP280_ODR_1000_MS;
rslt = bmp280_set_config(&conf, &user_bmp);
rslt = bmp280_set_power_mode(BMP280_NORMAL_MODE, &user_bmp);
struct bmp280_uncomp_data ucomp_data;
uint8_t meas_dur = bmp280_compute_meas_time(&user_bmp);
printf("Measurement duration: %dms\r\n", meas_dur);
uint8_t i;
for (i = 0; (i < 10) && (rslt == BMP280_OK); i++) {
printf("Running measurement: %d\n", i+1);
user_bmp.delay_ms(meas_dur);
rslt = bmp280_get_uncomp_data(&ucomp_data, &user_bmp);
int32_t temp32 = bmp280_comp_temp_32bit(ucomp_data.uncomp_temp, &user_bmp);
uint32_t pres32 = bmp280_comp_pres_32bit(ucomp_data.uncomp_press, &user_bmp);
uint32_t pres64 = bmp280_comp_pres_64bit(ucomp_data.uncomp_press, &user_bmp);
double temp = bmp280_comp_temp_double(ucomp_data.uncomp_temp, &user_bmp);
double pres = bmp280_comp_pres_double(ucomp_data.uncomp_press, &user_bmp);
printf("UT: %d, UP: %d, T32: %d, P32: %d, P64: %d, P64N: %d, T: %f, P: %f\r\n", \
ucomp_data.uncomp_temp, ucomp_data.uncomp_press, temp32, \
pres32, pres64, pres64 / 256, temp, pres);
user_bmp.delay_ms(1000);
}
if(rslt != BMP280_OK){
printf("Result not okay at measurement: %d\n", i);
}
}
