September 2011
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LED Matrix Reboot!
After a long hiatus, it’s time to revisit the LED matix project.
Pattern generation on board. Most of Ishani’s fun procedural patterns are fast enough to run on the AVR (at least for 8x8).
Live editing of animation and pattern parameters from the PC.
Accelerometer and microphone input to influence pattern parameters. VU meter, anyone?
Accelerometer based tap interface. Change...
October 2010
5 posts
August 2010
3 posts
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July 2010
10 posts
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Timing Refinements
Using the DS’s hardware timers, we can generate very accurate shutter times. Setting up a timer is easy:
void timerStart(int channel, ClockDivider divider, u16 ticks, fp callback)
There are four channels available. The native clock frequency (~33513.982 kHz) can be divided (by 1, 64, 256 or 1024) and the number of clock ticks (u16, max 65,535) in a cycle can be set. Finally, a...
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(very simple) GBA cart bus code
Since we don’t need to address anything, outputting data to the GBA cartridge bus is super-simple.
First we need to make sure that the ARM9 has control of the bus, like so:
sysSetBusOwners(true, true);
Then we simply write to the cartridge SRAM address:
memcpy((void*)0x0A000000, &data, 1);
Reading, assuming you only want the current state of the data lines (no addressing) is equally...
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Brief update on the state of the 16x16 LED matrix
This has been on hold for a while due to the USB interface not recognizing correctly. I thought this might have been due to a floating TEST pin, but this appears not to be the case. In order to get this project out the door, I may just use the bare main board to gang the four displays together and run the whole thing from a modified Rev 3 board and be done with it.
GLiP →
Interactive puzzle using 8x8 LED matrices.
May 2010
7 posts
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WatchIt’s alive!
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Motor Control
The motor is controlled with an ATTiny13. We PWM the motor driver’s enable line, with an external speed control via an ADC. Motor speed and direction are measured using a pair of photo-interrupters and a lego pulley to make a simple quadrature encoder. The encoder is read with a little interrupt routine on the Tiny. By watching the rising and falling edges of one output and...
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As I am far too lazy
to start another blog for other projects, I’ll be adding them here. The MAME coffee table project will remain separate. Stay tuned for a few new projects including:
A GBA cartridge for NDS similar to the one the Open Camera Control guys are making,
Some animatronics for my friend over at Le Cil Vert,
And a few more surprises to come.
The LED matrix project is not dead. I’m...
March 2010
1 post
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October 2009
1 post
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August 2009
2 posts
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Big Chill
I dragged Ishani’s Rev2 to the Big Chill this past weekend. Initially, we were planning on making a run of the stripped-down Rev3 to hand out, but a stack of other committments got in the way.
In the process, I learned some valuable lessons:
Battery life “in the wild” will always be shorter than expected. We got between two and three hours out of it with a typical pattern. ...
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WatchIt’s mounted in a picture frame. So.. yes. Yes it is.
July 2009
2 posts
3 tags
It's alive!
Rev2 is up and running, blinking and blending away on Ishani’s desk.
After much cogitation, it would appear I swapped data in and data out to the MAX6960 while swapping pins in the firmware to match the new board layout. I can never remember from which perspective those are supposed to be interpreted.
As always, there are still some issues with Rev2:
When it is turned off but plugged in...
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June 2009
5 posts
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Rev2 boards are back...
…and lookin’ pretty sweet (will post pictures shortly). I put the tabs on the display board the wrong way around, so the USB connection and switches will be obscured by the strap. I think we’ll assemble two anyway, for fear of never getting anything done.
Still having trouble sourcing the MAX6960s for any reasonable price, which is a shame. I’ve not been able to produce...
May 2009
10 posts
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Holy Macaroni
It’s been a busy year in the 64-pixel space. This enterprising lad is getting dangerously close to The Awesome. He must be stopped congratulated and given a slice of cake.
That said, he and this guy have put together some pretty nice minimal board designs that might need to be plagiarized provide inspiration for the consumer version. I reckon we could knock the parts cost down below ten...
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Watch10 minutes with Rev1 and some new Badge tool code…
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WatchIgnition! Captured on a Lumix FX150, here’s John’s salvaged Rev1 prototype running a few of the default demo sequences…
Stuff to notice:
+ per-frame controllable brightness, for pulse-y epileptic fun
+ text scrolling - super easy to make, just type words into the Badge tool and it does all the work
+ tasty polar plasma! (3rd shot)
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Battery Operation
Things got really hot when I soldered in the battery this morning. Turns out I’d made a silly mistake wiring the charging circuitry. If the battery hadn’t had it’s own overcurrent protection, we might have had a pretty nasty fire. Anyway, one pin-lift and the device is now free-standing.
In other LED news, check out these fancy LED invitations.
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The Awesome, Rev 1
It turns out the Rev 1 boards were salvageable after all. Some clever bending of leads, wedging-in of tiny resistors and a couple of green (I use yellow) wire fixes and we’re up and running.
April 2009
2 posts
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64-pixel Fun
While the boards are being redone, here are some other projects in the 64-pixel space.
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Back to the drawing board...
The microcontroller board just has too many errors to continue.
The flash memory is in a SOIC-wide package and barely fits on the pads.
I forgot the pull-up resistors on the memory as well, which requires a very fiddly green wire fix.
I didn’t include a programming header for the AVR, which seemed like a good idea at the time. It was not.
At this point, the amount of time it will take...
March 2009
2 posts
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Success... sort of.
I finally got some time to test out the boards for the LED badge project. I jumpered up the matrix driver board in parallel with the prototype and it works! This is exciting because I have a terrible track record with professionally manufactured boards.
I wired the colors up backwards, but we can always fix that in software.
As promised, more pictures to come.
Anne: Yes I am reading :)