Summary of Thermometer using DS1621 and Nokia 3310 LCD interfaced with ATmega8
This article describes a thermometer project using an ATmega8 microcontroller, DS1621 temperature sensor, and a Nokia 3310 LCD. The system operates at 3.3V via an LM317 regulator, updating readings every second. It utilizes I2C communication for the sensor and custom library functions for interfacing, with font generation handled by LFG software.
Parts used in Thermometer using DS1621 and Nokia 3310 LCD:
- Nokia 3310 LCD
- DS1621 temperature sensor IC
- ATmega8 microcontroller
- LM317 voltage regulator
- LED
- LFG application (LCD Font Generator)
I am presenting one application with the Nokia 3310 LCD: Designing a thermometer using DS1621 temperature sensor IC. DS1621 is 8-pin sensor from Maxim, with temp range of -55 to +125 degree C, which can be interfaced with microcontroller over two-wire serial i2c bus. It has operating voltage range from 2.7 to 5.5v. I’m operating it here at 3.3v, same as the one driving the LCD and ATmega8. DS1621 doesn’t require any external components to measure temperature. It has got continuous or one-shot temperature reading capability to save power.
Check out the schematic:
Here is the Proteus ISIS simulation result:
I’m using here LM317 for getting 3.3v supply, any 3.3v rgulator can be used to replace it. The LED is only for checking the health of the circuit incase nothing comes up on display. The circuit is programmed to update temperature appx. every second.I’ve taken help of LFG application for generating different sizes of fonts for the LCD, thanks o the author M.Ebrahimy. The application can be downloaded from here:
LCD Font Generator
I’ve created library functions for DS1621 interface with AVR using ICCAVR compiler. This functions can be used with i2c base routines discussed in my earlier posts. You can download the project source code here.
For more details, click : Thermometer using DS1621 and Nokia 3310 LCD interfaced with ATmega8
- What is the operating voltage range of the DS1621 sensor?
The DS1621 has an operating voltage range from 2.7 to 5.5 volts. - How is the circuit powered to achieve 3.3V?
An LM317 is used to get 3.3V supply, though any 3.3V regulator can replace it. - Can the DS1621 measure temperature without external components?
Yes, the DS1621 does not require any external components to measure temperature. - What interface protocol connects the sensor to the microcontroller?
The DS1621 interfaces with the microcontroller over a two-wire serial i2c bus. - How often does the circuit update the temperature reading?
The circuit is programmed to update the temperature approximately every second. - What tool was used to generate fonts for the LCD?
The LFG application was used for generating different sizes of fonts for the LCD. - Which compiler was used to create the library functions?
Library functions for the DS1621 interface were created using the ICCAVR compiler. - What is the purpose of the LED in this circuit?
The LED is only for checking the health of the circuit in case nothing comes up on display.
