Matrix user forums

Can anyone help?

I'm not receiving any UART signal in the 'receive box' of the 'standard' 5.StringReceive.fcf example from the RS232 folder. I have set up the HP488-00-3 MCU development board for LVP (Low Voltage Programming) because my UART signal is 0volts to 2volts so should be ideal for the LO<1volt and HI>1volt. The only modification I have made to the flowchart is to delete the LCD aspect of it so just left with the RS232(0) RECEIVE (which is all I need). Leaving aside any issues regarding quality/accuracy/timing etc., I was expecting to get at least something, if only gibberish!
The flowchart is set as per the standard one mentioned above and using hardware UART1.
The board is set up for LVP as follows:-

PIC16F88
The input signal BAUD rate is 9600 which I selected in the flowchart config area.
The displays are switched 'OFF' (can't use cos RB2 is used for UART Receive on this PIC)
RB3 is used on LVP select jumpers as this PIC requires it
J20 and J29 set to 'USB'
J14 all set to 'DIG'
S2 set at 'XTAL'
S4 set at 'FAST'
My Uart is connected to PORT B, GND and RB2

I run the set up with USB lead connected and the flowchart RUNNING but there is no sign of anything being received. I realise with the flowchart LCD , it would be showing that nothing is being received (Y plus two dots over it)

What have I done wrong?

Hope you can help c'os spent a few hours with no luck so far is probably something simple but tried all sorts.

Dear Christoph,

Be aware that using LPV not all pins can be used as output pins. Can that be the reason of not working correctly? Look in the datasheet of the microcontroller used.

Kind regard

Jan Lichtenbelt

Hi Christoph.

Am I right in understanding? You have a board sending data via RS232, and Flowcode running in simulation mode on the PC at the other end. Though Flowcode will simulate send and receive of data, it does not receive and display data via the physical RS232. For this you need a terminal such as HyperTerminal or TeraTerm. With this set up right you should see (at least gibberish) coming from your transmitted data.

Cheers,

Jonny

Jan Lichtenbelt wrote:Dear Christoph,

Be aware that using LPV not all pins can be used as output pins. Can that be the reason of not working correctly? Look in the datasheet of the microcontroller used.

Kind regard

Jan Lichtenbelt

You are right - that can often be a problem but I have taken that into account but appreciate your thoughts - Ta!

Cheers

Chris

JonnyW wrote:Hi Christoph.

Am I right in understanding? You have a board sending data via RS232, and Flowcode running in simulation mode on the PC at the other end. Though Flowcode will simulate send and receive of data, it does not receive and display data via the physical RS232. For this you need a terminal such as HyperTerminal or TeraTerm. With this set up right you should see (at least gibberish) coming from your transmitted data.

Cheers,

Jonny

Hi Jonny,

Not quite - I have a radio transmitting the necessary information in binary and a radio receiver receiving binary but outputting a SERIAL UART signal ( 9600,N,8,1 ) in the format (for example) 10 31 4C E6 86 which is essentially 5 bytes taking about 1mSec each and repeated every 16 mSec's. In other words: 5 mSec of data, then no data for 11 mSec, then 5 mSec of the same data and so on. I have to have a voltage shifter because the receiver output logic is 0v to 3.3volts and the HP488 Matrix M. development board is 0v to 5 volts as you may know.
I am able to put those hexadecimal codes into the flowchart simulator via the '+' sign on the transmitter panel OK but with the receiver outputting to RB2, I get nothing. I'm using the 16F88 PIC. It also precludes using the LCD as that also uses most of Port B. I don't mind gobbledegook as long as I get something - I can sort out timings and so on if not quite right at the moment, later! On this basis, the question is; am I right to assume that, all things being correct, I should see this signal appearing in the recieve box on the flowchart whilst running the simulation live from the signal input via the HP488 terminal connected to RB2 on the PIC16F88 ??

I had a reply from Ben this morning which was in relation to voltage levels but I also asked him the same question about my 'assumtion' but I would like to push ahead asap so an answer from either or both of you would confirm that I should be able to do this.

Thanks for any thoughts you may have on this,

Regards,

Chris

Hello Chris,

Why not use a 40 pin chip on your HP488 board say a 16F877A. This would move the UART to portc allowing you to use serial and the LCD.

You do not get the real world data showing on the simulation window. The simulation is stand alone and data can only be added to this by adding data to the incoming queue by clicking the + icon on the RS232 simulation while the sim is running.

To get data in the real world you really need to be able to display it on something to ensure you are correctly receiving data.

If its any help, here is a link to TeraTerm, one of the better terminals. Use this to receive the incoming data or to send output data from it. You will need to set this up to the right port/baud, etc first.

http://hp.vector.co.jp/authors/VA002416/ttermp23.zip

Jonny

Personally I use RealTerm but I think this and TeraTerm are very similar.

For anyone out there who fancies making their own terminal program this is a great tutorial for use with the free version of VB 2010 Express Edition.

http://tiktakx.wordpress.com/2010/11/21 ... -net-2010/

You could start with the terminal and then modify it to automate some process with your embedded hardware

OK Many thanks to Jan, Jonny and Ben for your input and have now got the PIC16F877A ready to go but no time to check it out yet with Christmas and all that coming up and while I am about it - a Very Merry Christmas and Prosperous New yewr to you fellas and all other V4 Forum'ers!