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i2c: remove smbus helper library & clean up command use in API

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This commit changes the mraa_i2c_read() API call behaviour, a register should
now always be set when using this call. The smbus helper library is no longer
required since the code is now all contained from i2c.c which avoids multiple
function calls

Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>
This commit is contained in:
Brendan Le Foll
2014-11-18 16:09:08 +00:00
parent e9de25d797
commit 19d7dad364
8 changed files with 146 additions and 546 deletions
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15
examples/i2c_HMC5883L.c
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@@ -99,11 +99,24 @@ main(int argc, char **argv)
mraa_i2c_write(i2c, rx_tx_buf, 2);
for(;;) {
#if 0
int i = 0;
//alternative, equivalent method which helps to understand exactly what
//the below does
mraa_i2c_address(i2c, HMC5883L_I2C_ADDR);
for (i = 0; i < DATA_REG_SIZE; i++) {
mraa_i2c_read_byte_data(i2c, HMC5883L_DATA_REG+i);
}
#endif
// first 'select' the register we want to read from
mraa_i2c_address(i2c, HMC5883L_I2C_ADDR);
mraa_i2c_write_byte(i2c, HMC5883L_DATA_REG);
// then we read from that register incrementing with every read the
// chosen register
mraa_i2c_address(i2c, HMC5883L_I2C_ADDR);
mraa_i2c_read(i2c, rx_tx_buf, DATA_REG_SIZE);
// this call behaves very similarly to the Wire receive() call
mraa_i2c_read(i2c, rx_tx_buf, HMC5883L_DATA_REG, DATA_REG_SIZE);
x = (rx_tx_buf[HMC5883L_X_MSB_REG] << 8 ) | rx_tx_buf[HMC5883L_X_LSB_REG] ;
z = (rx_tx_buf[HMC5883L_Z_MSB_REG] << 8 ) | rx_tx_buf[HMC5883L_Z_LSB_REG] ;