Need some help on my research on PIC18F4520.

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There's not much point using an antique 74C922 with a micro-controller, just scan the keypad directly - there's a 16F example in my tutorials.
 
Nigel Goodwin said:
There's not much point using an antique 74C922 with a micro-controller, just scan the keypad directly - there's a 16F example in my tutorials.
Click to expand...

haha i have no choice as this is the program my sch use.. i just started to learn on mct( microcontroller technology).. my teacher give us a problem which is design a calculator that can key in complex number.. my part is research on keypad...

all is base on problem-base learning... i not very good at java stuff so hope to slowly learn it...

just to add that the encoder information:

https://www.fairchildsemi.com/ds/MM/MM74C922.pdf

above one is teacher give us to refer.... and base on that to find information..

but too bad i keep finding those project things.. which does not really help me on understanding of how to apply it on PIC... i just submit some research to her, but she told me it is too difficult for me to understand and it is not very useful on how you going to apply it... so hope to find some new websites that you all can recommend~~

teacher told us this to research:
-connection of device to PIC18F4520
-short description
-code
-flowchart/pseudo working

thank you~~
 
The 74C922 has a nibble output and a key pressed strobe. Almost any I/O port can use it. It's pretty simple to use, I used one on my old ELF1802 back in 1978.
We're not going to do your school assignment for you but if you post what you've done we can offer suggestions.

As for the 18F4520 the datasheet is a must read, there was / is an 18F reference manual on Microchips site and plenty of app notes there too.
 
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Thanks futz but I couldn't locate the 18F or Advanced PIC reference there. I recall Microchip had it there once upon a time but moved it. If I find it I'll post it here.
 


nah i not asking you all to do my assignment.. i just need more information on how to apply it into 18F4520.. this is only starting only where as i need to find relevant details about it.. just hope got good links from here~~ thank anyway~
 
Well if it was me I'd hook the data outs on the 74C922 to PORTD 0-3 and the strobe to PORTB.0
This would even allow for an interrupt driven keyboard routine instead of scanned.
 
blueroomelectronics said:
That's it, wonder why it's not with the other reference manuals?
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I found it with their Search. The trick was to search for 18C instead of 18F.

Big sites have these kind of problems sometimes. Too much stuff. Not enough hours in the day to keep it all organized.

My favorite computer parts store site (**broken link removed**) has the problem a lot. If you search for something, you'll often find 4 or 5 or 6 different listings for the product, with different prices on each page. Pick the best price and order.
 
lzr84 said:
haha a newbie here.. don't understand at all..
Click to expand...

Well short of drawing you a schematic if you look at the datasheets you should be able to figure it out. Your instructor would have provided you some textbooks and a Google search should show plenty of examples.
 
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