Saturday, April 26, 2014

Minima - CPU Module Progress

I have made some progress on my Minima CPU Module.

I had previously created a Homebrew REV02 of this module, but had to stop construction while waiting for the Crystal. During the down-time, I decided to make some major changes to the board, and have been working on REV04 of that layout effort every since.

But the Crystals came in, and I just could not talk myself into creating another 70 "vias" on a new board layout.

So, I decided to continue the build on the REV02 board, even though knowing it would not work in an actual Minima environment (it was missing some critical Minima circuit connections). It will work for experiments and while learning the Bootloader and Farhan's Raduino Sketch.

The Ardunio Bootloader Installed - Using an ISP

After the REV02 board was built, the next task was to download and install the Arduino Bootloader. I had an USBTinyISP kit that I had not built, but, therefore it was also untested.
Minima CPU Module and USBTinyISP
as used to install the Arduino Bootloader
With a little work, some head scratching, and some jumper wires, I got the Arduino Bootloader installed on my raw ATmega328 processor. Because the LCD uses some of the same pins used by the "In Circuit Serial Programmer" (ISP), the LCD was removed.

The Ardunio Bootloader took about 20 seconds to install.

The Radiono Sketch Installed - Using a Prop-Plug

Because I have one, I have previously decided to "try" to use the Prop-Plug (USB to TTY Serial) converter to install Farhan's Raduino Sketch from the Arduino IDE. Again, with a little work and research the sketch was install successfully.
Radiono Running after Sketch Installed
The Prop-Plug is lower-right, the Minima VFO is lower-center, the Tuning Pot is lower-left, and the LCD sets on header on top.

I knew from reading posts on the Reflector, and seeing a local implementation, that I wanted to make changes to the Radio's Human Interface, all change seem to work very well. But, only after actual connection to the Minima (yet to be finished) will I know for sure.

After the last few changes are made to REV04 of this module, I will have to decide whether to send it out for manufacturing, or do a another Homebrew Toner Transfer build.


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