i am using 16f877a pic, my project is to control 3 fans . If we press an alphabet it has to goes to high state(ie,1 in led) for 1st fan and goes on. If i again press the particular alphabet ie, a fan in an on state it has to now move to off state(ie,0). I have completed half of it. Pls help if u can. I am using rs232 as a communication protocol
Please explain what is exactly your problem, maybe you can upload code that we can see it. Is it necessary to use ASM? I mean there is a lot of free C compilers even for 16f877, but for such simple task there should not be problem to write it in ASM.
i think you are trying to connect the mc with pc right ?
for this first fetch the data by usart protocol (you can see this in pic data sheet ) then compare the codes that you fetched from system then according to that set the relay pin.