exactly! I could have written the PIC code in like a day and had it work perfectly, but "that's not the point of designing an embedded system". We had to use an 8088 and all its associated logic as a part of the assignment. After figuring out the old processors, it's pretty easy to decipher what's going on with the newer processors, so i think that was their reasoning behind forcing the 8088 on us.marshallh wrote:Did you have a choice of what MCU to use? It seems pretty antiquated to use an 8088 when you could use a PIC16F877 and eliminate most of the logic gates as well as the eeproms. At least you learn more using the 8088
Why not use a HD44780 LCD screen instead? If you run one in 4-bit mode, you can get away with 6 IO pins. Some people have used that along with a serial-parallel chip and only 3 pins are needed. I assume the keypad is multiplexed?
Yeah, I've used the hitatchi LCD before for a wireless thermometer project and it's pretty easy to use, but it would have been extra work that wasnt required. As it was we ran out of time to finish it, we got like 95% of it to work, but it's super hard to find a software bug on an embedded system. We had to light LEDs to figure out where we were in the program and we couldnt use the logic analyzers to make sure that the correct data was being processed because the analyzers dont work in real-time.
PICs are so much better.
). the idea is that you will be able to scale it to whatever application you have, since you can just chain as many registers as you want... heres some conceptual stuff i did last night, without even really looking at datasheets:
