This sale only includes chip preloaded with bootloader and Blink sketch.
Base circuit has only power capacitor 100nF, reset pull-up 10k, crystal 16MHz
and two 22pF ceramic capacitors, optionally power indicator and test indicator
on pin 19 (P13). You might want to have few of these handy in your drawer.
Click to zoom
In order to work with Arduino IDE, you will need UART module (e.g. USB to UART).
You may even power your circuit through the UART module, connect:
- UART's GND to breadboard minus
- UART's TX to ATMEGA's RX
- UART's RX to ATMEGA's TX
- optionally and if available UART's DTR to ATMEGA's RST through 100nF capacitor
- optionally and if available UART's Vcc or 3.3V or 5V to breadboard plus
If your UART module does not have DTR, and you need to reflash the chip,
a somewhat awkward method may get you by temporarily - when IDE is done
compiling and says "Uploading", ground RST momentarily or cycle power to
the chip. This will cause reset and bootloader takes control. If you do
this by touching wire to wire, it may not always work. However, if you
are not utilizing serial communications, you may make your program to
reset on incoming serial data.