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/*
* Copyright (c) 2018 Samsung Electronics Co., Ltd.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an AS IS BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <unistd.h>
#include <peripheral_io.h>
#include "log.h"
#define ARTIK_I2C_BUS 1 // ARTIK I2C BUS
#define SRF02_ADDR 0x70 // Address of the SRF02 shifted right one bit
peripheral_i2c_h distance_sensor_h = NULL;
static int _open_distance_sensor(void)
{
int ret;
// open i2c handle for I2C read/write
if ((ret = peripheral_i2c_open(ARTIK_I2C_BUS, SRF02_ADDR, &distance_sensor_h)) != 0 ) {
_E("peripheral_i2c_open() failed!![%d]", ret);
return ret;
}
return ret;
}
int resource_close_distance_sensor(void)
{
int ret = PERIPHERAL_ERROR_NONE;
if (distance_sensor_h != NULL) {
// close i2c handle
if ((ret = peripheral_i2c_close(distance_sensor_h)) != 0 ) {
_E("peripheral_i2c_close() failed!![%d]", ret);
}
distance_sensor_h = NULL;
}
_I("resource_close_distance_sensor...");
return ret;
}
int resource_read_distance_sensor(uint16_t *out_value)
{
int ret = PERIPHERAL_ERROR_NONE;
unsigned char buf[10] = { 0, }; // Buffer for data being read/ written on the i2c bus
uint16_t range;
if (distance_sensor_h == NULL) {
// open i2c handle for I2C read/write
if ((ret = _open_distance_sensor()) != PERIPHERAL_ERROR_NONE ) {
_E("peripheral_i2c_open() failed!![%d]", ret);
return ret;
}
}
buf[0] = 0; // Commands for performing a ranging
buf[1] = 0x51; // Real Ranging Mode - Result in centimeters
// write mode command to sensor
if ((ret = peripheral_i2c_write(distance_sensor_h, buf, 2)) != PERIPHERAL_ERROR_NONE) {
_E("peripheral_i2c_write() failed!![%d]", ret);
return ret;
}
usleep(80000); // This sleep waits for the ping to come back
buf[0] = 0; // This is the register we wish to read from
// Send the register to read from
if ((ret = peripheral_i2c_write(distance_sensor_h, buf, 1)) != PERIPHERAL_ERROR_NONE) {
_E("peripheral_i2c_write() failed!![%d]", ret);
return ret;
}
// // Read back data into buf[]
if ((ret = peripheral_i2c_read(distance_sensor_h, buf, 6)) != PERIPHERAL_ERROR_NONE) {
_E("peripheral_i2c_read() failed!![%d]", ret);
return ret;
} else {
/*
* Location Read Write
* 0 Software Revision Command Register // If this is 255, then the ping has not yet returned
* 1 Unused (reads 0x80) N/A
* 2 Range High Byte N/A
* 3 Range Low Byte N/A
* 4 Autotune N/A
* Minimum - High Byte
* 5 Autotune N/A
* Minimum - Low Byte
*/
range = (buf[2] << 8) + buf[3]; // Calculate range as a word value
}
#ifdef DEBUG
_I("Range : %u Cm", range);
#endif
*out_value = range;
return ret;
}
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