Baja Prototype, Day 1

(Reposted from old blog)

Well, after a day or so of work on the prototype, I have some fun stories….

Starting with forgetting to connect the negative lead of the power supply to the chip on the protoboard, which led to about 2 hours trying to figure out why the chip worked on the devboard (STK500) but not on my breadboard. The ‘obvious’ culprit, term used loosely, was the chips clock source had been set to an external clock, which the STK500 supplies, my breadboard does not. I was convinced it had to be somewhat complicated and never thought to check something as simple as the power connection. Yeah. I feel dumb. I’m so oblivious that I tried a factory fresh chip and when it exhibited the same problem, decided they must have made a mistake there. That’s my ego for you.

Next, you may notice a blue-backed LED backlight 2×20 character LCD module in that picture, I’m trying to reconnect that and make it work with the new version of my LCD driver code. Well I fail at counting, reading or something else because tonight I couldn’t even get it to power up. Not a big deal, I got the compiler/flashing circuitry running, power supply is up, heart is beating, and I can hook up the LCD next weekend, or during the week if I find time…

So, to sum this up, here’s what I accomplished:

• 5V Power Supply Working, but they need filtering capacitors
• Off-board programming of the chip, so I don’t need to swap it back and forth constantly
• AVR-GCC w/ avr-libc configured on the Baja T30, avrdude configured to flash through the STK500
• Project imported from Subversion and debugged to point of compiling and starting.
• Initial firmware is booted and running, though there’s no sensors or display to see it with.

Here’s what I plan to do in the next few sessions:

• Get the LCD module wired up and running, this is pretty much the only path forward from here, any other option will be exceedingly difficult without this real time feedback.
• Get the 3.3V power supply and Dataflash online, start recoding and debugging the driver code for that.
• Get the serial port up and running, and start receiving/decoding NMEA packets from the eTek GPS Receiver.
• Get the tachometer/inductor working with the interrupts.
• Get the thermal sensors online with the ADC
• Put all of this on a nice, shiny, Printed Circuit Board.

And obviously, with the exception of the first one, this are in pretty arbitrary order. Now, for those that stuck with me through this whole post, a list of the days screwups:

• The aforementioned lack of connecting Ground wiring to the processor.
• Reversing MISO/MOSI (The input and output) data lines on the programming circuit jumpers to the prototype board.
• Forgetting to install all the base code chunks the compiler uses (avr-libc).
• Shocking myself countless times on the wall power pack.
• Touching the regulator when its been active all day (Ow!)
• Reversing the ribbon cabling adapter for the LCD (Twice)
• Not remembering to enable the interrupt for the timer and having the processor do a whole lotta nothin’
• Eating at Ro-Bro before starting.

That’s all for now, enjoy the attached photos of the work space and keep an eye out for further updates.

Photos:

Prototype, Day 1, Photo 1

Prototype, Day 1, Photo 2

Prototype, Day 1, Photo 3

Prototype, Day 1, Photo 4