25 February 2005 - 11:02
Light at the end of the tunnel...
The term is flying by, but luckily so is our progress on the
WIMP. The overall design has been finalized and PCB schematics
have been layed out. We decided to go with a PCB manufacturing
companing in the U.S. named PCB123,
they offer free PCB layout software, and quick turnaround on
orders. Also, first time users get 25% off their first order,
which was a nice bonus. We're all crossing our fingers in hope that I didn't make any mistakes on the layout, and if all goes well we should have the boards in our hands, and soldered, by next Friday. When this is completed there will be few days of coding to do, and then we'll be turning our attention towards the final report.
PCB123 Software & WIMP Schematic
~steve
23 November 2004 - 16:54
i2c you...
Alan and I spent a few hours today fooling around with i2c and a LCD disiplay. Up to this point the LCD had only been used using RS232 communications to send data to it, but when we discovered that it was also i2c compatible we figure it would be good test for Cam's i2c assembly code. After a few attempts, and a few minor changes to Cam's code, we got it to work.
My next challange is to start migrating the PIC over to a 3.3V enviroment. Everything up to this point has run at 5Volts, but our DAC & MP3 Decoder chip only run at 3.3V, so now I've got to start testing the PIC out at 3.3Volts, and try to figure out how to get data from a 5V PIC to a 3.3V PIC.... oh joy!
~steve
23 November 2004 - 16:42
Flash-tastic II...
After a long weekend of programming/debuging and a few tears of
frustration, we now have a serial loader program that can read, write,
and format our 4mbit AMD flash memory chip from a PC. For the PC side of the serial loader Kelley wrote a java program that can open a file and send it over a comm port (RS-232) and read data back to output in a file. On the hardware side I wrote assembly code for a PIC16F877a to receive requests from the PC over RS232 and then store/retrieve data from the flash memory, using code Alan and I wrote on Friday. A transfer is initialized by the PC sending a request to the PIC with the proper opcode, the PIC will then respond with an ACK, then the data transfer begins. Data is transfered in 128 byte blocks until all the data is transfered.
So we are now able to load the flash chip with the neccessary information to initalize our mp3 decoder chip and store some mp3 data to test if we've wired everthing together properly. Yay!!
~steve