After getting into arduino it can get very costly to get arduino boards for projects and so here is a tutorial how to get to next level by getting all parts from board to a circuit significantly reducing cost.
Step 1: Get an Atmega328 With Arduino Uno Boot Loader on It.
You can get hold on them from aliexpress or banggoog for cheap like 2 dollars each with. bootloader or for 1 dollar without bootloader.
Step 2: Other Parts
Things needed are :
1 Atmega328p with arduino uno bootloader
2 16.000 mhz crystal oscillator
3 2 * 22 or 27 picofarad load capacitors
4 0.1 microfarad capacitor
5 6 pin ttl programmer
6 jumper cables
Step 3: Connections
pin1 to 0.1 micrograms capacitor
pin 9 and 10 to crystal oscillator
load capacitors if 22 pf from pins 9 and 10 to pin 8
positive end of led to pin 19 and negative to pin 22.
Step 4: Connections to Programmer
dtr to 0.1 microfarad capacitor's empty end.
vcc to pin 7
gnd to pin 8
rx to pin 3
tx to pin 2
Step 5: Uploading Sketch
Hook the programmer to pc and program from arduino ide as arduino uno