Interfacing PIC18F46K22 with DS18B20 sensor and SSD1306 OLED

This post shows how to implement a simple temperature measurement station using PIC18F46K22 microcontroller and DS18B20 digital temperature sensor.
The PIC18F46K22 MCU reads temperature (in °C) from the DS18B20 sensor and print its value on SSD1306 OLED display (128×64 pixel).
MikroC PRO for PIC compiler is used in this project.

In this project the SSD1306 OLED is configured to work in I2C mode, make sure that your display is configured to work in I2C mode, some displays need jumper placing or some soldering.

To see how to interface PIC18F46K22 MCU with SSD1306 OLED display (I2C mode), take a look at the following project:
Interfacing PIC18F46K22 with SSD1306 OLED display | mikroC Projects

Hardware Required:

  • PIC18F46K22 microcontroller   —->  datasheet
  • SSD1306 OLED display
  • DS18B20 temperature sensor    —->   datasheet
  • 4.7k ohm resistor
  • 5V source
  • Breadboard
  • Jumper wires

PIC18F46K22 with SSD1306 OLED and DS18B20 sensor circuit:
The image below shows project circuit diagram.

PIC18F46K22 DS18B20 SSD1306 OLED circuit

All the grounded terminals are connected together.

The DS18B20 temperature sensor has 3 pins (from left to right): GND, data and VCC where:
GND is connected to circuit ground (0V)
Data pin is connected to pin RD5 (#28) of the PIC18F46K22
VCC is connected to +5V.

The PIC18F46K22 microcontroller has 2 hardware I2C modules (MSSP1 and MSSP2 modules).
In this project I2C1 module is used with SDA1 on pin RC4 (#23) and SCL1 on pin RC3 (#18). The SDA1 pin of the MCU is connected to the SDA pin of the display and the SCL1 pin of the MCU is connected to the SCL pin of the display.
The reset pin of the display is connected to pin RD4 (#27) of the microcontroller.

The SSD1306 OLED display DC pin is connected to VDD which means I2C slave address of the device is 0x7A.

In this project the PIC18F46K22 microcontroller runs with its internal oscillator @ 16 MHz, MCLR pin is configured as an input pin.

PIC18F46K22 with SSD1306 OLED and DS18B20 sensor C code:
The following C code is for mikroC PRO for PIC compiler, it was tested with version 7.2.0.

To be able to compile the C code below with no error, a driver for the SSD1306 OLED display is required, its full name (with extension) is SSD1306OLED.C, download link is the one below:
SSD1306 OLED mikroC library

for more information about this driver, visit the following post:
SSD1306 OLED display library for mikroC compiler | mikroC Projects

after the download, add the driver file to mikroC project folder.

The reset pin of the SSD1306 OLED display is defined in the C code as shown below:

Function used in the C code:
unsigned int ds18b20_read(): reads temperature from the DS18B20 sensor, returns the value of the temperature as unsigned 16-bit number.

Rest of code is described through comments.

Full mikroC code:

The following picture shows a protoboard circuit of the project:

PIC18F46K22 with SSD1306 OLED and DS18B20 temperature sensor

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.