TFT EGG TIMER + THERMOMETER
LCD TFT is digital display at its best, it displays versatile clear picture. The picture is built by entering the address and the color of a pixel or rectangle, so it's simple to use too.
Timer based on PIC16F876A 1.8" LCD TFT Module. Included C code, and circuit diagram. Time span is 1 second to 99 minutes. Setting the time is by Min and the Sec pushbuttons. To reset the time press Sec and Min simultaneously. Pressing start/stop starts the countdown. When the time reaches zero the buzzer sounds
in low volume and then the volume increases.
DS18B20 TERMOMETER
DS18B20 digital sensor has temperature reading of -55 to 99.99 centigrade. The sensor doesn't require calibration. The software updates the reading every 10 seconds.
LCD modules vary depending on the drive IC. The
TFT module in the project has the driver ST7735 . I bought this module directly from China because the price was more sensible.
 
Circuit Description
See also Technical Tips
DS18B20 is a digital temperature sensor.
The buzzer is driven by a frequency of 2KHz, a piezo buzzer for that frequency will give optimal output.
The crystal is 16 MHz, refer to the data sheet for the recommended capacitors. Most crystals use 22pF.
Link between pins 11 and 12 connects CCP2 driving TMR1 and CCP1 to give timebase of 1 sec.
Pushbuttons can be any type. Pressing the Sec and Min together resets the time.
The TFT module has the driver ic ST7735, The inputs of the ic tolerate 5V,
one source is: https://www.ebay.co.uk/itm/1-8-inch-1-8-TFT-LCD-Display-module-ST7735S-128x160-51-AVR-STM32-ARM-8-16-bit/191786659555?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649
TFT EGG TIMER WITH TOUCH SCREEN
Timer based on PIC16F690 and 2.4" TOUCH TFT Module. Included C code, and circuit diagram. Time span is 1 to 99 minutes. Setting the time, start and reset is by 4 touch buttons on the screen. To stop touch the screen anywhere. When the time reaches zero the buzzer sounds for 20 seconds.
OPTINAL DS18B20 TERMOMETER
An option to add DS18B20 digital sensor to the circuit and have temperature reading of -55 to 99.99 centigrade. The sensor doesn't require calibration. The software updates the reading every minute.
TFT module uses driver IC ILI9341.
You are free to use the circuit diagram and the software with no limitations.
 
Circuit Description
See also Technical Tips
DS18B20 is a digital temperature sensor, it's an optional component.
The buzzer is driven by a frequency of 2KHz, a piezo buzzer for that frequency will give optimal output.
The crystal is 32768 Hz, refer to the data sheet for the recommended capacitors. Most crystals use 22pF.
3V Vdd supply to the pic16f690 is connected to the 3V regulator on the TFT module.
The diodes drop the 5V to about 3.4V supply to the LED screen illumination.
I bought this module from here: http://www.ebay.co.uk/itm/3-3V-240x320-2-4-SPI-TFT-LCD-Touch-Panel-Serial-Port-Module-PBC-ILI9341-/191654806614?hash=item2c9f844456:g:8RYAAOSwd0BVwu2u |
Technical Tips