Can I use a UNO to program a Pro mini clone?

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1

I found out that the pro mini is really cheap. I've decided to buy it but I want to know if I've to buy a USB to Serial converter or use the UNO instead to program it. I remember seeing a post that uno can be used to program other microcontrollers.

If it can be done

  1. Which of UNO's pins would be used?
  2. How do I do it?

Thanks!

2

You can remove the ATmega chip from the Uno board, and use pin 0 (RX), pin 1 (TX), RESET and GND to the Pro Mini.

If you keep the ATmega chip in place, it starts its bootloader if a reset is issued to upload a sketch. Perhaps it can be made to work without removing the ATmega chip, but I'm not sure.

3

It doesn't have a separate ICSP header so I don't know whether it supports ICSP, but it does have SPI and a reset line so it might support ICSP. If it does, you could use the 'Arduino as ISP' sketch on your Arduino to upload the sketch to the Pro Mini. There are plenty of tutorials showing you how to do this.

Although I don't have a Pro Mini, it looks to me as if the conventional way to program them is via the serial pins (i.e. via its bootloader). You could use the Uno as a USB-to-serial converter as Erdin describes to achieve that. Since USB-to-serial converters are relatively cheap you might want to just get one, to save the hassle and wear and tear of using the Uno.