.. | ||
.github/workflows | ||
examples | ||
test | ||
.arduino-ci.yml | ||
DS18B20_INT.cpp | ||
DS18B20_INT.h | ||
keywords.txt | ||
library.json | ||
library.properties | ||
LICENSE | ||
README.md |
DS18B20_INT
Minimalistic library for the DS18B20 temperature sensor - restricted to one sensor per pin.
Arduino Temperature Control Library (ATCL)
This DS18B20 library is a minimalistic library for a DS18B20 sensor. It will give only temperatures in whole degrees C. Goal is to minimize footprint.
If you need more functions or control over the DS18B20 family I refer to the library of Miles Burton - https://github.com/milesburton/Arduino-Temperature-Control-Library
I'm a great fan of the above library however some time ago I needed to strip it down to save a few dozen bytes. I reworked that minimalistic version into a library and I added a number of Arduino examples to help you get started.
Interface
This DS18B20_INT library supports only the DS18B20, only one sensor per pin, no parasite mode, no Fahrenheit and no alarm functions. The only feature the class supports is the asynchronous reading of the temperature by means of three core functions:
-
DS18B20_INT(onewire) constructor needs a reference to OneWire object.
-
bool begin(uint8_t retries = 3) resets oneWire and set resolution to 9 bit.
returns true if all is OK. there will be a number of retries to connect, default 3. -
void requestTemperatures() trigger temperature comversion
-
bool isConversionComplete() check if conversion is complete
-
int16_t getTempC() returns temperature in whole degrees only. -55..125
-127 = DEVICE_DISCONNECTED -
bool getAddress() returns true if the sensor is configured (available)
Operation
This library supports only one DS18B20 per Arduino/ MCU pin.
// BOTTOM VIEW
//
// PIN MEANING
// /---+
// / o | 1 GND
// | o | 2 DATA
// \ o | 3 VCC
// \---+
Connect a pull-up resistor 4.7 KOhm between pin3 and pin2. When the wires are longer this resistor needs to be smaller.
Check examples.
Pull up resistor
An indicative table for pull up resistors, (E12 series), to get started.
Note: thicker wires require smaller resistors (typically 1 step in E12 series)
Length | - 5.0 Volt | - 3.3 Volt |
---|---|---|
10cm (4") | 10K0 | 6K8 |
20cm (8") | 8K2 | 4K7 |
50cm (20") | 4K7 | 3K3 |
100cm (3'4") | 3K3 | 2K2 |
200cm (6'8") | 2K2 | 1K0 |
500cm (16'8") | 1K0 | * |
longer | * | * |
* = no info, smaller
Credits
Miles Burton who originally developed the Arduino Temperature Control Library. and all people who contributed to that lib.