For this project I've used those parts:
1. 4 digit 7 segment display common anode
2. Atmega8 microcontroller
3. 7805 voltage regulator
4. 16MHz quartz
5. 2 x 22pF
6. 1N4001 diode
7. 100uF electrolytic cap
8. 100nF ceramic cap
9. female headers
10. DC barrel power jack connector
11. prototyping board
12. some wires from a HDD ribbon cable.
13. LM335 themperature sensor + 2 x 1K resistors
The tools used in this project are:
- Soldering iron
- Solder pump
- Soldering wire
- Wire strippers
- Third hand
- Poxipol to glue the barrel jack connector to the board
As inspiration I've used THIS PROJECT and THIS PROJECT.
The schematic is made by myself in Fritzing using the descriptions from that project. So, like you have already seen I didn't actually bothered to change the order of the pins in the code to avoid that crazy wiring. The code is made so you don't need any resistor for the display because each anode is controlled using PWM.
First tests were made using Arduino UNO R2 and then after the code was ok, I've started the building. There are also 3 photos with some details when the board was almost 90% finished, I think. The last photo is with LM335 temperature sensor added to the counter. The sensor is connected to A2 pin of Atmega8.
Link of the counter code: here
Link of the thermometer code: here
Note that thermometer code require the sevseg library for Arduino. You can find the library RIGHT HERE!
This is it! I hope you enjoyed and don't forget to press FOLLOW+ button! :) Cheers!
P.S.: Sorry for my spelling mistakes!