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Step 6Program the microcontroller with the firmware
You can now program the firmware into the microcontroller.
I use the USBtinyISP by ladyada.
I also designed this POV to be compatible with the Arduino. You just have to use the FTDI USB-TTL232 cable. But don't take my word for it, test it! (because I didn't).
There is also a TLC5940 library for the arduino by Alex Leone
Currently in this version of firmware you can only display one image, but you can easily tweak it. Also, the image data is read from program memory.
In the future I plan to try a SPI EEPROM connected to the serial port. This way I am able to store tons of images and animations!
In this version there is also a small section of feedback control loop, to synchronize the image to the velocity of the wheel.
How much space do I need for my image?
Depends on the level of detail you desire. With level of detail, I mean the number of divisions of your wheel.
If want to use 100 divisions, you'll divide the circle in lines with 3.6 deg. The greater the number of divisions, the narrower the lines.
For one image of 100 lines:
192 bits for each colour * 3 colours for line = 576 bits / 72 bytes for each line
72 bytes/line * 100 lines = 7200 bytes/image, ~7kBytes/image
I use the USBtinyISP by ladyada.
I also designed this POV to be compatible with the Arduino. You just have to use the FTDI USB-TTL232 cable. But don't take my word for it, test it! (because I didn't).
There is also a TLC5940 library for the arduino by Alex Leone
Currently in this version of firmware you can only display one image, but you can easily tweak it. Also, the image data is read from program memory.
In the future I plan to try a SPI EEPROM connected to the serial port. This way I am able to store tons of images and animations!
In this version there is also a small section of feedback control loop, to synchronize the image to the velocity of the wheel.
How much space do I need for my image?
Depends on the level of detail you desire. With level of detail, I mean the number of divisions of your wheel.
If want to use 100 divisions, you'll divide the circle in lines with 3.6 deg. The greater the number of divisions, the narrower the lines.
For one image of 100 lines:
192 bits for each colour * 3 colours for line = 576 bits / 72 bytes for each line
72 bytes/line * 100 lines = 7200 bytes/image, ~7kBytes/image
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Jul 15, 2010. 11:58 AMkoko44
says:
If we assemble microcontroller to the pcb, how can we program the firmware?
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3
Jul 19, 2010. 3:32 PM
Hazard (author)
says:
Hazard (author)
says:
The board has a ISP connector
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Jun 23, 2009. 10:59 AMglompos21
says:
Can you tell us the algorithm that you are using to transform the image into bytes?
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3
Jun 24, 2009. 4:46 AMHazard (author)
says:
Hazard (author)
says:
Sure! But in the next few days I'll be very busy. I'll get to it when I get the time. But I can tell you that each line from the matrix, is one radial line of the wheel. And since it is 12bits for 16 LEDs, and the microcontroller is 8 bits, I used a line of 24bytes in length. This results in the information of each dot, being overlapped. Like: (8) (4,4) (8) (8) (4,4) (8) this stores information for 4 dots, with the low and high n*bble overlapped, alternating.
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Jun 23, 2010. 3:31 PMschroedc
says:
I'm still struggling to correlate the image to the data bytes as well. Can you elaborate w/an example?
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