Previously I shared an article about Arduino Pro Mini, a tiny board for miniaturizing your projects. As the board does not have any USB interface we need a USB to TTL module. But if you have an Arduino uno (DIP version) you don’t need any programming modules. So without wasting any more time, lets get started.

Requirements:

Here is a list of components you will need to get started:

  • Arduino Uno DIP version (the SMD version cannot be used)
  • Arduino Pro Mini with Header pins soldered on
  • Breadboard with Jumpers
  • LED

Once you have gathered everything lets move on to prepare the Uno for programming.

Preparing Arduino Uno for Programming:

First make sure you have the DIP version (Dual Inline Package) of Arduino. We have to remove the ATmega 328 controller IC from the socket. You can use a flat head screwdriver to carefully pop out the IC from one side at a time.

NOTE:- Before you pop the IC out, notice the notch on the IC, this notch matches with the notch on socket. While putting the IC back in socket, the notches should match or the IC will be damaged.

Once the IC is out, we can start making the connections.

Connections:

The connections are fairly simple. First solder the header pins to your Pro mini and connect it on bread board.

Circuit Diagram

Follow the connections as shown in the diagram above.

  • Mini’s Vcc = UNO’s +5v/3.3v (depends on the board you have)
  • GND = GND.
  • Tx = TX (pin no. 1)
  • Rx = RX (pin no. 0)
  • DTR = RESET.

In some cases the pro mini may not be programmed in that case just swap the TX & RX pins. That’s all with the connections , next step is to upload the code.

Uploading The Code:

  • Open Arduino IDE .
  • Connect Your UNO to PC.
  • Select the right port.
  • Go to tools >> Boards >> Select Arduino Pro mini.
  • Got to tools >> Processor >> Select the type of board you have. ( I am using Atmega 328 3.3v 8Mhz)
  • Now upload the code. ( I’ve uploaded blink example for demonstration )

Connect an LED to Pin 13 of your pro mini to check if the program is successfully uploaded.

Any code can be uploaded in a similar way, after the code is uploaded you can disconnect the UNO and the Pro mini can be used as stand alone controller.

If you have any doubts or questions feel free to ask in the comment section.