Monday, November 30, 2009

Porting to the Sanguino (ATMega644p)

Over the weekend, I duplicated the 'Satpack' breadboard, this time using an ATMega644p micro-controller, which offers twice the programming space, EEPROM and, perhaps most important for debugging radio-control software, two hardware serial ports.
Bootloading this with my USBTinyISP  was a complete snap, in part because this chip puts all the SPI pins beside each other. I used the Arduino environment to bootload, following the instructions at http://sanguino.cc

Monday, November 16, 2009

DS32C35 Real-time Clock Chip Success

I've been breadboard-testing the DS32C35 RTC after soldering this SOIC-20 onto a sparkfun breakout board, and I'm happy with what I've got: for Arduino use, everything 'just works'.

Monday, November 9, 2009

Real-Time Clocks for Breadboard Projects

Just as I was about to make my video on qrpTracker, I melted the DS1307 real-time clock. Here's how it happened, and some solutions I found for breadboarding a real-time clock at 3.3v.

Wednesday, November 4, 2009

Video: Satellite Mode-Switching Through Self-Tracking

Here's a youTube video illustrating the way in which a micro-controller running Plan13 could be used to save power on board a satellite:

Tuesday, November 3, 2009

Generating Morse (CW) with Atmel Microcontrollers

As part of my qrpTracker project, I made a morse code signaling library for the Arduino. It uses callback functions so that the person using the library can specify exactly what happens when the signal goes 'on' and 'off'. It foregoes any sort of clever data-packing to store the dits and dahs and just calls functions within a long 'switch statement', an arrangement that I find more readable and just as compact after compiler optimization.

This library is more suited for integration into a larger project. For really small beacons, I like Alan VK2ZAY's  code posted in his 80m beacon project page, operating on a ATtiny13V! This was mentioned in a comment to a brainwagon posting regarding Arduino CW code.