SAMD21-DS18B20

A lightweight driver for MKR-series Arduino's and other SAMD21 circuits

Use case

If you're working on a project with a newer Arduino with the DS18B20 sensor, and you'll only have one sensor connected to your device, this lightweight driver might be for you.

I developed this lightweight library for the DS18B20 temperature sensor tailored specifically for the Arm® Cortex®-M0 32-bit SAMD21 processor. It was just a fun project to learn the OneWire protocol whilst also mitigating the need to import the huge OneWire library with DallasTemperature since I'm only ever going to use one sensor for my project which rendered a lot of code in those libraries unecessary for me and my little device with not-so-much memory to spare for luggage code.

I wanted to make it very easy to use and easy to read, should you need or want to change something in it yourself.

A few platforms that I'm aware of which use this silicon are:

• Arduino MKR1010 WiFi
• Arduino MKR1310 Wan
• Arduino MKR1000 WiFi
• Arduino MKR GSM 1400
• MKR Vidor 4000

Example

#include "DS18B20.h"

// Check the table in "DS18B20.h" if you need help with picking these values. 
// It will depend on where you connect the sensor to your device.
#define TEMP_PORT_GROUP      0
#define TEMP_PINMASK         PORT_PA16

// In this case, the data cable to the DS18B20 sensor is connected to physical port 8 on an MKR1010.
DS18B20 tempSensor = DS18B20(TEMP_PORT_GROUP, TEMP_PINMASK);

void setup()
{
    Serial.begin(38400);
    tempSensor.begin();
}

void loop()
{
    Serial.println(tempSensor.GetTemperature('C'));
    delay(1000);
}

See another example here

Limitations

• This driver only supports one DS18B20 connected to the device at a time.
• No temperature below 0 Celcius is reported - it stops at 0.0c. (If you feel like adding this feature, make a PR! :) )

Disclaimers

This driver has not been industrially tested and is for hobby purposes only. I, the author, do not condone the use of this driver in any health -or business critical use case and thus leave zero guarantees for that the values are correct at all times.