mekohler
- 25th September 2007, 06:39
My grandfather and I are undertaking a project to build a table lit by a 5 x 5 matrix underneath (composed of LED's). The schematic we followed is here:
http://www.injektilo.com/PICHelp/schematic.png
We used an exe to convert the "frames" of a "word" into a string of numbers and then another exe to convert it to a .bin, which is loaded into the EEPROM (24LC64).
For example, to spell TEST, the first frame is T, the 2nd E, etc...and the .txt output is:
1 1 31 1 1
0 31 21 17 0
0 23 21 29 0
1 1 31 1 1
This is then converted to a .bin:
http://www.injektilo.com/PICHelp/sequences.bin
Now we need to control the EEPROM to feed the LED's but we don't know how. We found this picture of someone who did the same project with the same schematic:
http://www.injektilo.com/PICHelp/PICT0003.JPG
Its obviously a microcontroller which connects to the 10 ports in the upperleft of the schematic (next to the 24LC64 EEPROM)...but I can't make out the connections on this circuit and I don't know how I would program it to access the EEPROM bits and "push" them to the Matrix one after the other, and cyle...so the table would read T, then E, then S, then T, then T, then E, etc.
I know this is alot, but we are so close to finishing and this is the first time we have done anything with PICs. Thanks for all the help guys.
Marcos
P.S. - The 4 chips above the expanders (PCF8574A) are http://www.electronelec.co.uk/uln2803a.htm
http://www.injektilo.com/PICHelp/schematic.png
We used an exe to convert the "frames" of a "word" into a string of numbers and then another exe to convert it to a .bin, which is loaded into the EEPROM (24LC64).
For example, to spell TEST, the first frame is T, the 2nd E, etc...and the .txt output is:
1 1 31 1 1
0 31 21 17 0
0 23 21 29 0
1 1 31 1 1
This is then converted to a .bin:
http://www.injektilo.com/PICHelp/sequences.bin
Now we need to control the EEPROM to feed the LED's but we don't know how. We found this picture of someone who did the same project with the same schematic:
http://www.injektilo.com/PICHelp/PICT0003.JPG
Its obviously a microcontroller which connects to the 10 ports in the upperleft of the schematic (next to the 24LC64 EEPROM)...but I can't make out the connections on this circuit and I don't know how I would program it to access the EEPROM bits and "push" them to the Matrix one after the other, and cyle...so the table would read T, then E, then S, then T, then T, then E, etc.
I know this is alot, but we are so close to finishing and this is the first time we have done anything with PICs. Thanks for all the help guys.
Marcos
P.S. - The 4 chips above the expanders (PCF8574A) are http://www.electronelec.co.uk/uln2803a.htm