Counter for ATMega328P-PU No Need Arduino Board No Shift Register and No Transistor.

Now I would like to show you how to make a counter using common anode. no shift register no transistor needed for small leds. If you have common cathode, no problem just change the LV to HV and vice versa.

The beauty of micro controller is that we can cost down our project by eliminating some component by changing the logic or code in the micro controller. I am referencing on

What makes this project tricky is to make some pin (D2-D8) as ACTIVE LOW and (D9-D12) as ACTIVE HIGH.

Some reset is needed before setting the data out to 7 segment since we are mixing ACTIVE Low and active HIGH.

Step 1: Assemble Your Breadboard

You only need a cristal, 2 20pf cap, 1 nf ceramic or 0.1uF elco can do. The pull down resistor is optional.

You can use any USBTTL that has 5V GND RX TX DTR. All of these pins is needed to program your ATMEGA328P-PU. The best is FTDI one or CH340 as long as all pins above exist.

To minimize hassle, please use ATMEGA328P-PU.with arduino boot loader. Put a led serial with resistor 330 ohms into pin 19 (D13) if you want to try your assemble was fine by running blink test.

After all ok you can continue to next step.