Get data from Lidar Lite V3 over I2C (Zephyr os)

[John Ivan Fox]

Hi,

I am trying to get the data from the Lidar Lite V3 sensor via the I2C bus. However, I only receive a 0 back.
So my question is the implementation generally correct?

Lidar V3 datasheet: https://static.garmin.com/pumac/LIDAR_Lite_v3_Operation_Manual_and_Technical_Specifications.pdf

Overlay file:

&arduino_i2c { /* i2c */
    compatible = "nordic,nrf-twim";
    status = "okay";
    clock-frequency = <I2C_BITRATE_FAST>;
};

prj.conf file:

CONFIG_LOG=y
CONFIG_I2C=y
CONFIG_I2C_NRFX=y
CONFIG_STDOUT_CONSOLE=y
CONFIG_PRINTK=y

main.c file :

/*
 * Copyright (c) 2012-2014 Wind River Systems, Inc.
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <zephyr/kernel.h>
#include <zephyr/drivers/i2c.h>
#include <zephyr/logging/log.h>

LOG_MODULE_REGISTER(main);

#define I2C_NODE		DT_ALIAS(arduino_i2c)
#define LIDAR_I2C_ADDR	0x62
#define I2C_DEV_NAME	DT_NODELABEL(arduino_i2c)
#define DELAY_TIME K_MSEC(500)



void main(void)
{
	uint32_t i2c_cfg = I2C_SPEED_SET(I2C_SPEED_FAST) | I2C_MODE_CONTROLLER;
	const struct device *const i2c_dev = DEVICE_DT_GET(I2C_DEV_NAME);
	uint8_t data[2] = {0};
	int i2c_device_ready, ret = 0;

	if (i2c_dev == NULL || !device_is_ready(i2c_dev)) {
		LOG_INF("I2C: Device is not ready.\n");
		return;
	}else
	{
		LOG_INF("I2C: Device is ready.\n");
	}

	if (i2c_configure(i2c_dev, i2c_cfg)) {
		LOG_INF("I2C config failed\n");
		return;
	}
	while (1) 
	{
		ret = i2c_reg_write_byte(i2c_dev, LIDAR_I2C_ADDR, 0x00, 0x04);
		if (ret) {
				printk("Error writing to reg 0x00! error code (%d)\n", ret);
				return;
			}
		
		while (!i2c_device_ready)
		{	
			uint8_t ready = 55;
				ret = i2c_reg_read_byte(i2c_dev, LIDAR_I2C_ADDR, 0x01, &ready);
			if (ret) {
				printk("Error reading reg 0x01! error code (%d)\n", ret);
				return;
			}
			if (ready == 0){
				i2c_device_ready = 1;
			}
			printk("data ready: %d \n", ready);
			k_sleep(DELAY_TIME);

		}
		i2c_device_ready = 0;	

		ret =  i2c_burst_read(i2c_dev, LIDAR_I2C_ADDR, 0x8f, &data, sizeof(data));
		if (ret) {
			printk("Error writing to FRAM! error code (%d)\n", ret);
			return;
		}
		printk("data: %d \n", (data[0] << 8 + data[1]));
	}

}

[Menon]

Hello,

First of all I am not familiar with this sensor. But the registers you mentioned in the program looks okay for  me from the data sheet. In the overlay file you need to mention the sensor as child node to the i2c controller (depending on which i2c you have used). You need to add something like below in the overlay file.

&i2c0 {        // depending on your i2c controller
    
    lidar: lidar@62{
        compatible = "i2c-device";
        reg = < 0x62 >;
        label = "LIDAR";
    };
};

// This is just a reference

Take a look at this tutorial from Nordic which explains the interfacing of a digital temperature sensor via I2c. In this they mention how you can edit and update the overlay and prj config.

Kind Regards,

Abhijith