Matrix user forums

Attempting to use an RS232 board to interface data (at 57600 bps) to a PIC16F88. Any one any ideas if this will work or how to approach this?

Regards
Dave.

Hi Dave, there is an RS232 strategy document on the Eblock members area
http://www.matrixmultimedia.com/datashe ... rategy.pdf

This has some info.

One thing to watch for is that the Pins you need are on Port B not Port C as is usual for larger chips.

The 16F88 datasheet can be usedto get most of the settings and register values you need.

Hope that gets you started.

Post if you need more help, as it can be tricky stuff comms.

Hi Ian

Thanks, will do.

One thing I am concerned about is the speed (constrained to 57600 bps)

The flowcode settings stop at 32k....

Any suggestions?

Regards
Dave

The RS232 component for FlowCode has a few limitations at the moment (for example, the BAUD rate is quite limited and it assumes the PIC is running with a 19.6608MHz crystal). We will address these limitations once FlowCode v3 has been released and make it more flexible.

Your best bet may be to use either 'C' or Assembly. This will give you much more control over the RS232 speed settings. As you are a FlowCode user, you could look at the generated 'C' code to get an idea of what the commands should be and you can embed your customised RS232 'C' routines into FlowCode.

The speed shouldn't be a problem. Looking at the datasheet for the 16F88, 57.6k is possible, although you may need to select your clock frequency carefully.

Hi Steve
I have used an 877A to interface with this unit and also have used the rs232.hex file to check all my hardware (All ok, correct response(s) recieved).
The 57600 hz output from my sensor however will not display correctly when plugged into modem connection of the rs232 board....
Copying the text output from the unit using hyperterminal capture and pasting it into the PC connection on the rs232 board allows the text to be displayed correctly to the LCD board.

Two questions:
1- Can I alter the 9600 baud on the rs232.hex file?
2- I would like to take the ascii output from the unit above, seperate the parameters (csv delimited) and use these values within a flowcode routine.
Any suggestions?

Regards
Dave

Hello Dave,

I'll ask Ian to dig out the FlowCode file for the RS232 program and send it to you. However, I don't think it's possible to set this to run at 57.6kHz.

As for your second question, you should be able to set up a routine that continually monitors for incoming characters. When a comma is received, then you know you have received one parameter and can then begin looking for the next one.

As I've said previously, we will be looking at the RS232 component within FlowCode in the next month or so. Hopefully we will be able to improve its features and offer a faster BAUD rate.

mmm
Ok thanks for the help

Regards
Dave.

Sorry, Dave. I know the RS232 component needs some work. I'm hoping to spend some time on it once we've put FlowCode v3 to bed.

A quick update on this topic:

The latest download of Flowcode (released on Jan 22nd) contains an updated RS232 component that is much better, and it will allow a baud rate of 57600.