Keyboard interfacing the Propeller LED Display
transmitting end:
Keyboard->8051 for interface->encoder-> transmitter
receiving end:
receiver-> decoder -> microcontroller(8051 family)
what about using HT640 & HT648 for encoder & decoder, and RX433 & TX433 for RF receiver & transmitter?
The thing which i dont know about is programming MC at receiving end for saving the character to appropriate memory location, and thats where the problem arises, because i dont know whether 8051 program can access the code memory or not.
Please guys, help me out.
what about using HT640 & HT648 for encoder & decoder, and RX433 & TX433 for RF receiver & transmitter?
yes it is better option
because i dont know whether 8051 program can access the code memory or not.
8051 can only access data memory mean RAM
it can't access ROM
Its a good innovative idea
In the programming part for writing the new message, is there any other idea than using an "if-else" type loop for recognizing the character?
i thought of using a switch on the propeller for displaying & writing a new message..if realtime is possible, then it would be great..
as i said it is possible... currently code read data from ROM, change it to ram after it runs.. thats it..
i thought of using a switch on the propeller for displaying & writing a new message..if realtime is possible, then it would be great..
I did not get this.. :/ what are you trying to say?
so are you saying that i just have to save the new characters to those memory addresses? In your code, its #40h. Isn't that a ram address?
In your project code, the message to be displayed is loaded to ram area in that "ramc" segment, right?nitheeshas
"ramc" is a subroutine that moves the message from rom [0x600] to ram [0x40]
so are you saying that i just have to save the new characters to those memory addresses?nitheeshas
Yes store it at 0x40 in ram.
In your code, its #40h. Isn't that a ram address?nitheeshas
Yes.
The address does not decide whether it is ram or rom.
There is a address 0x40 in ram and in rom/flash
in my point of view that are ROM locations
ORG 40H
means place this code starting at 40h location of program memory
that code can be any user define string or compiler generated code that is called hex file
The address does not decide whether it is ram or rom.
There is a address 0x40 in ram and in rom/flashExperimenterUK
so then what determines if its a ram or rom location?
anyways, this is the rough sketch of the code i'm having in mind:
org 0013h
acall input
reti
..
..
..
input:
loop:
mov r0,#40h ;or other ram address
mov a,p3
anl a,#bbh ;clearing P3.2 & P3.6; P3.2 is being used for ext0 interrupt
zero:
cjne a,#00h,one
mov @r0,"0" ;ascii value of zero
ajmp next
one:
cjne a,#01h,two
mov @r0,"1" ;ascii value of one
ajmp next
..
..
..
..
z:
cjne a,#88h,next
mov @r0,"Z" ;ascii value of z
ajmp next
next:
dec r0
cjne a,#ffh,noexit ;ffh is programmed to be the key corresponding to exit the character input sequence
ret
noexit:
ajmp loop
Literally, this is my first program, so i expect a lot of errors..
Please help me to figure them out..
@ajay bro: i saw an additional capacitor in the main circuit pcb in the picture that you have attached in your project, but its not in the circuit..can you pls explain what it is used for?
[ Edited Mon Jan 23 2012, 11:29 pm ]