wish to learn microcontroller....... need your help

[Ian Rogers]

Do you know where to start??? If I send you a little program, would you be able to program your chip?....

Also... Have you a schematic for your board?

 

[ikelectro]

no, I don't have the schematic..
how should i start, no idea...

 

[Ian Rogers]

Ok! Tonight I'll post a walkthough (if I have enough time)

Just tell what pins the LED's and switches are on...

 

[ikelectro]

Just tell what pins the LED's and switches are on...

you mean how to lighten a LED????

 

[ikelectro]

now i understand.... the LEDs are connected to 16 and 17 number pin of the micro with 10KΩ res.....
but what about the switch??

 

[Ian Rogers]

now i understand.... the LEDs are connected to 16 and 17 number pin of the micro with 10KΩ res.....
but what about the switch??

Two push buttons??

I very much doubt they are 10k resistors that means less than .5mA to light them....

 

[ikelectro]

Two push buttons??

o yes.. they are connected with pin no. 21 & 22.

I very much doubt they are 10k resisters that means less than .5mA to light them....

no doubt, they are 10k... i double check them ....

 

[Ian Rogers]

o yes.. they are connected with pin no. 21 & 22.


no doubt, they are 10k... i double check them ....

Are they connected to the pins via a transistor? 5v-2v * 10k = 300μA.. This cannot be right surley...

 

[ikelectro]

No transistor!!!!

 

[Ian Rogers]

Sorry... I couldn't get near the computer last night... My son was home from Liverpool unexpectedly, so I was busy..

I'll try and do some tutorials tonight...

 

[ikelectro]

Ok. no problem!!!
after all it's your son..i'm not in hurry.

bye the way, im just returning home with the prints of the pdf which u gave.

 

[Ian Rogers]

Why don't you like PDF's on the computer.... I find it more useful as I work on the computer more than the bench..... When I run a simulation in ISIS I have all the datasheets open then I can flick though them when I need them......


Having them printed out just clutters up the desk..

 

[ikelectro]

I just can't staring at the computer too long.

 

[Ian Rogers]

Oh dear!!! This must be why I'm going blind

 

[ikelectro]

It is very stressful after all.
Now i'm reading the memory structure!!!!!!!

 

[Ian Rogers]

This is the biggest difference between micro's

8051 is linear, and along with the four ports you can actually connect any device to a memory location... This makes the micro more of a full processor... Sometimes a good thing to have, the downside is that you lose two bidirectional ports.

The PIC series have paged memory, and not all the same size... However they have oodles of peripherals on board.. You can't use the memory as i/o ... Its just a micro...
One upside is the new parallel port... You can use this similar to a data bus and connect to other devices... LCD's come to mind..

The ATMEL AVR is similar but has linear memory... It too can boast tons of internal peripherals... But also can't map memory to i/o..

I think ( Its my opinion ) that the paged memory is the biggest issue on the PIC.. ( I'm talking mainly about the 8 bit systems)

 

[ikelectro]

please correct me if i'm wrong :
8051 is more simple (as it uses flat memory) to program than PIC which uses Page memory...

Sometimes a good thing to have, the downside is that you lose two bidirectional ports.

i just lost here....

 

[Ian Rogers]

please correct me if i'm wrong :
8051 is more simple (as it uses flat memory) to program than PIC which uses Page memory...

That's what I mean by linear, same as flat...

i just lost here....

8051 has four ports P0, P1, P2 and P3.... If you choose to memory map peripherals, then P0 and P2 are lost as they are needed for the Address and Data bus..

Leaving P1 and P3...

 

[ikelectro]

If you choose to memory map peripherals, then P0 and P2 are lost as they are needed for the Address and Data bus..

Is that mean if i interface the 8051 with some other devices (such as TTL logic, CMOS etc.) I have to chose P0 and P2 as input and output?
is that correct?

 

[Ian Rogers]

Yes...

If you want to use the 8051 as a micro, you can use all the ports as I/O... connect to different devices

ALSO you can use P0 and P2 as a full 16 bit address and multiplex P0 for data... This way you can interface MANY MANY devices.
You can use an address decoder, a data latch and you can connect loads of devices..... External parallel SRAM for instance. When using a graphical LCD and SD storage you will find this kind of expansion a god send....