I spent Thursday & Friday evenings wiring up enough of the board to flash some LEDs, then set out to program it… Without success

After ripping apart the board, replacing the uC, and checking every single connection with a 10x Loupe, i turned to google, and found that the atmega128 is programmed differently to the other AVRs i’ve used, it has it’s own PDI and PDO pins connected to the first USART for uploading the program.

I wish someone had told me that before i bought the board!

Luckily, i had brought the USART pins out to their own header on the board, so after wiring up a programming adaptor, i was finally able to get some life!

After waiting for some new parts to arrive ( 1206 resistors dont fit on 0805 pads :/ )  I’ve sat down to do some assembly tonight.  Hopefully i’ll  manage to get it lighting those LEDs this week.

Got into work this morning after two weeks sunning myself in Menorca to find my boards have arrived!

I’ll have to make a start at populating them tonight, see if i can’t get it flashing some lights or something for UKMM 08!

I’ve just sent off the board design for R2, 5 boards should arrive in a couple of weeks!

Hopefully i’ll be able to get the regulator all the LEDs and the processor working for the end of June, so i have something to show off at UKMM 2008!

Here are some renders i’ve exported from Gerbv Gerber Viewer, looking good!

Its time to move on to a new micromouse, and I have decided all details of my new mouse (Hardware & Software) will be released under Free / Open Licenses.

The Hardware is under the TAPR Open Hardware License, with the email address r2@thinkl33t.co.uk

The Software is under the GNU General Public License

In addition to the above Licenses, I ask that if you make your own R2, or use a modification of R2’s subsystems in your own micromouse,  you publish a webpage on your creation!  I can provide hosting for single pages or pdf files, or a blog service such as Blogger or WordPress can be used to keep a full log of the project. Email me the link to your page, and I’ll link it from the main project page.

So, it was time for RoboTIC 07, and… I’d done nothing with R1v2 since June!

Since the only huge hardware problem i’d been having was with the sensor board, I decided it was time to rebuild it from scratch, and move to a more technologically advanced sensor, so… i shamelessly copied from Min4A, one of the top Singaporean mice.

So, i had decided on using the TSL262, now the problem was to find them! The only place they seem to be available in the UK, farnell, sells them for £3 each in small quantities (pn: 1182351), and since i could find them for $2.52 (about £1.25) each from Mouser in the US (pn: 856-TSL262R-LF), i decided to import a pile of them, and resell what i didn’t need. After perusing the datasheet, i found a good matching Infra Red LED (pn: 859-LTE-209), and put in an order for 50 pairs.

A week later they arrived, along with a nice customs bill, so including delivery, they cost about £2 each, still 1/3 cheaper than it would have been buying locally.

After some planning, and trying different methods of coupling the TSL262 to my ATMega32 uC, i decided to go for simplicity, and coupled the output of my test sensor directly to an ADC. The LED was connected to an IO pin set to output, and tied to ground via a 330Ω resistor.

It gave much more repeatable results than the old sensors, between 5/1024 for no wall at all, and 50+/1024 when there is a wall nearby. Since it seemed to work as expected, with no major glitches, So i moved onto a small stripboard sensor.

This sensor was tested by being plugged into the sensor board plug. Once i had it working, I soldered a sensor board connector to a second piece of stripboard sized to fit in the sensor board slot at the front of the mouse.

Once tested, I built another of the sensors, and attached both to the front and rear of the left side of the micromouse using sticky foam pads, and built a third sensor on the sensor interface board.

So, the hardware of R1v2 is now complete!

Come back soon, when i’ll be walking through the toolchain used to program the mouse, and release the full schematics of the mouse.

I’ve just managed to get the sensors working in r1v2, thought it was time to update the worklog.

Sensors outputting:

Sensor input:

Sensor1 (front left): 49
Sensor2 (front right): 27
Sensor3 (left) : 25
Sensor4 (right): 26

Unfortunately, the sensor input doesnt seem too useful at the moment, as i’m getting either a lot of noise, or too little variance between the nearby and far away readings.

Today i managed to get the motors on R1v2 working properly. I also added a second LED, and wired up the rest of the header for the sensors.

Here is a short video of it running the motors on opposite directions. Tonight I’m looking at getting them working with timers and interrupts, reusing the code i wrote earlier: