Need Help - Using 8051 with RS232

[maxfourier]

I'm an electronics student working on my first project. I have explained my problem below. Need some help.

Please consider that I'm a newbie with projects.. I have only brought a few things and downloaded some software. Apart from that I have my logic ready. So, all i would need to do is write the code and program the microcontroller.


This is what i have :

Hardware :

8051 (NXP 80V51RD2)
RS232 with DB9
max232

Software :

Keil
Flash Magic


What i want to do : is just program the microprocessor. I have tried Googling "Interfacing 8051 rs232" but could not really get it.

I can interface the microprocessor and the max232 but I'm having problems interfacing the RS232.

Moreover, I have NO idea how (& where) to connect the RS232. Here is what my cable looks like :

**broken link removed**


Again, What i need to know is:
-Which side of the cable goes where(PC n 8051)
-How is it connected to the microprocessor.
-How do I write my c code into the microprocessor - How to convert it to hex(or whatever required)? Why do I need Keil & Flash Magic?

 

[john blue]

Try here: **broken link removed**

you will need to register as a member before you can view some restricted content. Hope this helps

 

[Ian Rogers]

**broken link removed** is the best place to learn about 8051/2 interfacing and programming..

 

[maxfourier]

I had already read the link (EngineersGarage) & in the image shown - i think they've connected the db9 end with the max32. then how does the other end connect to the pc? Moreover, what does their cable look like from the other side.

I have already interfaced the 8051 & the max232.

All i need now is how to interface the max232 & the rs232. And how to connect the rs232 to my pc.

 

[john blue]

It is there ?

**broken link removed**

 

[maxfourier]

Yeah, i found that. But, if you look at the cable i have (please find the image attached on the original post), I have one end which is a DB9 Female & the other end - i have no idea what that is.

1. In the figure, i think they've shows 9 pins. So that would be a DB9 MALE, right? But i have a female end and an "unkown" end.
2. Where is the other end which goes to the pc. How does it look? Or is this DB9 a port in the PC itself?

If the cable i have is the wrong one, then which one do i need?

 

[john blue]

I dont seems to see any image in your original post by the way. This DB9 port is an RS 232 port which most of the Desktop will have. The figure can be DB9 male or female

You will just need an RS232 to RS232 cable or a USB to RS232

 

[maxfourier]

I dont seems to see any image in your original post by the way. This DB9 port is an RS 232 port which most of the Desktop will have. The figure can be DB9 male or female

You will just need an RS232 to RS232 cable or a USB to RS232

It is there.. Anyway, here is the image : **broken link removed**
I'm really confused now, John. I think my cable is DB9 to "unkown".

 

[maxfourier]

Can you see it now ::

**broken link removed**

 

[john blue]

Nope. but it is in my mail the white connector should connect to the max232 and the DB9 should go to your Desktop .

 

[maxfourier]

AWESOME! It's weird the image isn't showing up here. Ok, so the DB9 goes to my desktop after i remove these screws.. DONE!
Now, a last problem. How do i connect the white thing to the max232?

 

[john blue]

you need the male part of that connector. Else, chop it away and use the respective 3 wires - GND, TX and RX

 

[maxfourier]

John, can you give me your email? I need to add pics.. I'm almost there.

 

[panic mode]

does this help?
https://i38.tinypic.com/6gimc0.jpg

as for connector, just trace the wires connecting to DB9 pins 2, 3 and 5
and if you cannot find mating connector, chop it off and solder wires to PCB

 

[maxfourier]

I got it, thanks