Sunday, November 30, 2014

AVR ISP Extender

I have played with microprocessors such as PIC and AVR. They both have advantages and disadvantages, and are fun to play with.

One thing about AVR that I have problem with is the ISP interface. The AVR ISP programmers use a 10-pin (or 6-pin) interface arranged in 5x2 (or 3x2). This is rather bread-board unfriendly. In comparison, the PIC ISP programmers use a 5-pin inline interface, which is much easier to connect. With some time in the weekend, I have decided to build a little board that brings AVR ISP into a more breadboard friendly form.

There are a few such attempts by other people on the internet. Here is one that is just expanding the space between the two rows. This is a little circuit board of the same idea from Sparkfun. This guide makes the circuit board yourself, and I like the way how the pin head is connected to the board.

This is quite simple, and I have all the connectors I needed. So I decided to get my soldering iron and make one myself just for the fun. Since I will be using a lot of 8-pin ATtiny processors, I decided to add a DIP8 socket so I can easily program those without needing to connect the wires every time. By the way, I found a nice compact bootloader that works on ATtiny's, so all I need to do is to burn the bootloader on.

So here is my AVR ISP extender. I tested it by programming a ATtiny chip, and it works well.
By the way, my pin out is as following:
  1. GND
  2. VDD
  3. MOSI
  4. MISO
  5. SCK
  6. RST
This is different from most others on the Internet. I also has two rows of inline connectors, one male and one female so it works with both arrangements when I need it.

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