aamicron

The MP3 Trigger I helped design with Jamie Robertson is featured (somewhat) on The Late Late Show with Craig Ferguson. Grant Imahara from MythBusters designed the robot and used the MP3 Trigger for the audio feedback.  Other SparkFun parts were used. He also hints some "similar circuitry" is used in the new generation of the Energizer Bunny (see 1:51)!

The MP3 Trigger controls the audio responses. Grant loads a MP3 on a microSD card, then when a signal is applied to the board, say a button press, one of the tracks on the SD card plays, simple as that. The magic is in the firmware design by Jamie Robertson.

The MP3 Trigger is the red board on the right. Looks like there is a Futaba RC receiver that probably controls the movements of the robot wirelessly, just as you would control a servo in a RC car or airplane.

Oh yea, SparkFun's AVC is this Saturday.

If you will be a guest at the 2010 SparkFun AVC, you will need to register here (except if you are coming with me, you know who you are). It is mainly to see how many people will be attending in addition to entry into some kind of raffle.

Here is my first snow run and last, (unless it snows on race day :) ), with the RC snowmobile before it gets converted into a street roadster. The sled ran really well on the packed snow, but as soon as it hit powder, it would bottom out.

This is the wheel modification I made for the competition vehicle. I decided to use some rollerblade wheels with bearings instead of the wheels I had before.

Those are plastic bushings I got from the hardware store that I am using as spacers. I might need to get a longer spacer for the one closest to the wheel.

I am just now starting on my code and am looking forward to use the XMEGA event system. Instead of using a bunch of interrupts, I can use a 2 clock cycles to talk between hardware peripherals on a dedicated channel, not a bus. For instance, you could use a pin change event to do an ADC conversion and an input capture on the Timer/Counter to get exact time-stamps for each conversion. Not really sure if I will even need a feature like this, but I haven't seen an event systems like this, so I am ready to get moving.
 

There are a handful of websites documenting the progress of the competition vehicles. Yikes. I'm a little behind, under staffed, and lacking sponsorship, even though I am a SparkFun employee (we can only spend $300 on SparkFun goods), so this for me is more just for fun ;).

Check out these sites, there is some pretty neat stuff being built.

A 600lbs. autonomous vehicle!? Last year we had some close calls with small RC cars heading into the crowd. Hopefully there is a kill switch on that thing!

RC Car Hack

Home brew bot with an expanded PVC plastic skeleton.

A wait-listed Motorola Driod robot.

UAV

Nuther UAV

If you have a competition vehicle, let me know if you would like to be listed here.

Next month SparkFun will be hosting the 2nd Annual Autonomous Vehicle Competition.

Here is the recap from last year. I was on the team RTFM. This year I will be the lone man on team Baayesmobile!

This year I have decided to hack an ArtAttack RC snowmobile into a street car for my autonomous platform. The reason for my choice is that the sled is really well built and should work great for a really sturdy water resistant robot platform. In addition, my ultimate goal is to have this thing follow me autonomously while I snowboard. I have a few tracking systems in mind.

These sleds are super expensive (at least $400 to get moving), but I happened to get a used one courtesy of Chris Fine at FindDesigns. He sold me one of his old racers for a couple hundred bucks; fully assembled, tested, and with after stock components and electronics, i.e. marine grade ESC, studded track, servo, beefy motor.

Here are the guts of the sled with Lew dog in the background. All I will need to control for turning, stopping, and starting will be, 1 standard 44 oz-in@4.8V servo and 1 brushed motor, both controlled via PWM.

These are the gears for the motor. Not sure if I will need to change the pinion gear for slow and precise motor control. I assume the sled is geared for really fast speeds.

I took off the skis to see how I was going to mount wheels. One problem that I see is that the wheel needs to be mounted so that when turning, the wheel has clearance below the control arm.

I removed the machine pin, that the wheel will be mounted to, from the control arm. The pin will need to be dropped or extended about 1.5 inches. I am doing this with a plate of low grade steel I will cut. Then I might have to spot weld the pin to the plate for added reinforcement, however I will need replacements if I ever want to use the skis.

Another issue is that the wheels will elevate the front end of the vehicle slightly creating less surface area of contact between the track and road. My solution is to use a slick loop of rubber, then support and weight the back end.

For the brains I will use the XMega100 from SparkFun. The MCU is only 8-bit, but can run up to 32MHz@3.3V, accurately enough for serial communication, and without an external crystal! Also, there is plenty of flash space and there are a few ports for every hardware peripheral; USART, SPI, two-wire, timers, counters, programmable interrupt controller, etc., so I won't run out of resources. The tool chain I will use will be AVRStudio and the hardware programmer I will use will be the AVRISPMKII.

BOM coming soon.

I have started writing libraries for some of my peripheral devices and will post once I have made some progress.

-Aaron