Hello there,

I'm trying to get a rangefinder sensor (link below) working with a Raspberry Pi Pico.

Sensor:
https://wiki.dfrobot.com/Infrared_Laser_Distance_Sensor_50m_80m_SKU_SEN0366?fbclid=IwZXh0bgNhZW0CMTAAAR01PcccLQxQ4WpxkyFXRAe8iviofnQn2KjtlCe5k-s5er6s0ondmOBm1eI_aem_8c3iMxLCBBxabE5iRlSWcA#target_0

At the moment using the below code, the sensor works perfectly when programmed with Arduino IDE.

For my project however, I need to get it working using VS Code and CMake. When I use the VS Code code it does not work, the raw data that the sensor receives is completely different. The code uploads but continuously reaches the printf("Invalid Data!\n"); line.

I've put code for the two IDEs below, as well as my CMakeLists.txt, any help/advice would be greatly appreciated,

Cheers.

Arduino IDE code:

// Command to set measuring range to 80 meters
char setRange[] = {0xFA, 0x04, 0x09, 0x50, 0xA9};
// Command to set frequency to 5 Hz
char setFrequency[] = {0xFA, 0x04, 0x0A, 0x20, 0xF3};
// Command to set resolution to 1 mm
char setResolution[] = {0xFA, 0x04, 0x0C, 0x01, 0xF5};

void setup() {
Serial.begin(115200); // Start USB serial communication
Serial1.begin(9600); // Start UART1 with baud rate 9600
pinMode(LED_BUILTIN, OUTPUT);

// Send commands to configure the sensor
Serial1.write(setRange, sizeof(setRange));
delay(100); // Small delay to ensure the command is processed
Serial1.write(setFrequency, sizeof(setFrequency));
delay(100); // Small delay to ensure the command is processed
Serial1.write(setResolution, sizeof(setResolution));
delay(100); // Small delay to ensure the command is processed
}

void loop() {
char buff[4] = {0x80, 0x06, 0x03, 0x77}; // Example command to request distance measurement
unsigned char data[11] = {0};

Serial1.write(buff, sizeof(buff));

while (1) {
digitalWrite(LED_BUILTIN, LOW);

if (Serial1.available() > 0) { // Check if there's data to read
delay(50);
for (int i = 0; i < 11; i++) {
data = Serial1.read();
}

unsigned char Check = 0;
for (int i = 0; i < 10; i++) {
Check = Check + data;
}
Check = ~Check + 1;

// Print the raw data
Serial.print("Raw Data: ");
for (int i = 0; i < 11; i++) {
Serial.print(data, HEX); // Print each byte in hexadecimal format
Serial.print(" ");
}
Serial.println();

if (data[10] == Check) {
if (data[3] == 'E' && data[4] == 'R' && data[5] == 'R') {
Serial.println("Out of range");
} else {
float distance = 0;
distance = (data[3] - 0x30) * 100 + (data[4] - 0x30) * 10 + (data[5] - 0x30) * 1 +
(data[7] - 0x30) * 0.1 + (data[8] - 0x30) * 0.01 + (data[9] - 0x30) * 0.001;
Serial.print("Distance = ");
Serial.print(distance, 3);
Serial.println(" M");
digitalWrite(LED_BUILTIN, HIGH);
}
} else {
Serial.println("Invalid Data!");
}
}
delay(20);
}
}

VS Code:

#include <stdio.h>
#include "pico/stdlib.h"
#include "hardware/uart.h"

const uint LED_PIN = PICO_DEFAULT_LED_PIN;

void setup() {
stdio_init_all();
uart_init(uart0, 9600);
gpio_set_function(0, GPIO_FUNC_UART); // TX
gpio_set_function(1, GPIO_FUNC_UART); // RX

gpio_init(LED_PIN);
gpio_set_dir(LED_PIN, GPIO_OUT);
}

int main() {
setup();

// Commands to send to the rangefinder
char setRange[] = {0xFA, 0x04, 0x09, 0x50, 0xA9};
char setFrequency[] = {0xFA, 0x04, 0x0A, 0x05, 0xF3};
char setResolution[] = {0xFA, 0x04, 0x0C, 0x01, 0xF5};

// Send commands
uart_write_blocking(uart0, (uint8_t *)setRange, sizeof(setRange));
sleep_ms(100);
uart_write_blocking(uart0, (uint8_t *)setFrequency, sizeof(setFrequency));
sleep_ms(100);
uart_write_blocking(uart0, (uint8_t *)setResolution, sizeof(setResolution));
sleep_ms(100);

while (true) {
char buff[] = {0x80, 0x06, 0x03, 0x77}; // Command to request distance
uint8_t data[11] = {0};

uart_write_blocking(uart0, (uint8_t *)buff, sizeof(buff));

if (uart_is_readable_within_us(uart0, 50000)) {
for (int i = 0; i < 11; i++) {
data = uart_getc(uart0);
}

uint8_t Check = 0;
for (int i = 0; i < 10; i++) {
Check += data;
}
Check = ~Check + 1;

printf("Raw Data: ");
for (int i = 0; i < 11; i++) {
printf("%02X ", data);
}
printf("\n");

if (data[10] == Check) {
if (data[3] == 'E' && data[4] == 'R' && data[5] == 'R') {
printf("Out of range\n");
} else {
float distance = 0;
distance = (data[3] - '0') * 100 + (data[4] - '0') * 10 + (data[5] - '0') +
(data[7] - '0') * 0.1f + (data[8] - '0') * 0.01f + (data[9] - '0') * 0.001f;
printf("Distance = %.3f M\n", distance);
gpio_put(LED_PIN, 1); // Turn on LED
}
} else {
printf("Invalid Data!\n");
}
}
sleep_ms(20);
}
}

CMakeLists.txt:

cmake_minimum_required(VERSION 3.12)

include(pico_sdk_import.cmake)

project(RangefinderProject)

pico_sdk_init()

add_executable(rangefindertest
rangefindertest.c
)

# Link the Pico SDK libraries
target_link_libraries(rangefindertest
pico_stdlib
hardware_uart
)

pico_enable_stdio_usb(rangefindertest 1)
pico_enable_stdio_uart(rangefindertest 1)

# Create map/bin/hex/uf2 files
pico_add_extra_outputs(rangefindertest)