Wireless modules - help with code not working

[Ioannis]

Hi Rob. Thanks for the files. I found also the corresponding sites too.

Ioannis

[Dick Ivers]

Rob,
I now have my two XRF transceivers set up and functioning. However, I'm experiencing the same problem as you have reported ... unable to communicate rf from a PIC and PBP.

The hardware and wiring checks out good. Using a terminal program (TeraTerm) and a USART to USB Bridge cable (CP210x), the radio loop-back link works perfectly. Also, the AT command mode functions correctly for both devices.

The comms do not work when driving the radio from a PIC USART. Sample code:

'**************************************************************************
'*Program to test XRF radio communications via loopback method            *
'*Uses a pushbutton switch on porta pin 4                                 *
'*Target processor is PIC 12f1822                                         *
'*321 program words, revised 05/05/2013                                   *
'*Program by Dick Ivers                                                   *
'*All rights reserved                                                     *
'************************************************************************** 
'set 12f1822 configurat1on
#CONFIG
  __config _CONFIG1, _FOSC_INTOSC & _MCLRE_OFF & _CLKOUTEN_OFF & _WDTE_ON
  __config _CONFIG2, _PLLEN_OFF & _LVP_OFF
#endconfig

'set registers
        OSCCON = %01101000   '4 mhz osc
        OSCTUNE = 0          'factory calibration
        ANSELA = 0           'all digital inputs
        OPTION_REG.7 = 0     'global pullups enabled
        WPUA = %010000       'porta pin 4 weak pullup enabled
        CM1CON0.7 = 0        'comparator disabled
        TRISA  = %011110     'PORTA.0 & porta.5 are outputS, all others input

    while OSCSTAT.0 = 0    'wait for stable freq.
    wend
    
    define OSC 4            '4 mhz oscillator

'Define hserout parameters 
    define HSER_RCSTA 90h
    define HSER_TXSTA 20h
    define HSER_BAUD 9600
    define HSER_CLROERR 1           'clear overflow error
    
    APFCON.7 = 1   'rx on ra1 (12f1822)
    APFCON.2 = 1   'tx on pin ra0 (12f822)
    
    i var byte
    char var byte


    For i = 1 to 3
    porta.5 = 0     'led on
    pause 333
    porta.5 = 1     'led off
    pause 333
    next
    

asleep:
    nap 2   'delay 4 ms
    if porta.4 = 1 then asleep
    

DT:
    hserout [dec 5]
    hserin 100,blink,[dec char]
    if char = 5 then
    porta.5 = 0    'led on
    goto halt
    endif
     
blink:
    porta.5 = 0     'led
    pause 50
    porta.5 = 1     'led off
    pause 50
    if porta.4 =1 then asleep
    goto DT   
   
halt:
    stop

I saw your latest post on the Ciseco forum. You are not getting much help there. Do you have any further test results?

Dick

[Ioannis]

@ tasmod:

You are using Serout with N9600 but I think the modules you are using need data be in true mode and not inversed. So use serout with T9600.

@ Dick:

I think for the 1822, you need to set TXSTA at $24. At $20 no 9600 is supported.

Look at page 299-300 of the data sheet.

Ioannis

[Dick Ivers]

Ioannis,
Thanks, I will try your suggestion. Unfortunately, not right now ... my computer broke down over the weekend. I'm writing this from a borrowed laptop.
Dick

[tasmod]

Hi Dick, Loannis,

I received the modules back on Friday just as I was leaving to have a few days away for the Holiday long weekend in UK.

They have been tested as OK but that doesn't relate as I couldn't measure any RF out when I sent them back. Never the less I believe Ciseco, so I'm continuing by etching two new pcbs with link pad outputs so I can link any pin to the module.

They should be complete today and populated. Then I will do more tests.

The speed issue came up so I'm running at 10MHz so 9600 should work reliably. As for True, well the Picaxe code sample seems to use N9600 but I seem to remember I didn't trust this. So I wrote a loop of serout/serin with all baud rates one after another for testing. I think I mentioned this earlier in the post. Ciseco claim any serial comms sent, will be echoed out. Their data sheet isn't any clearer.

I can use any pin/s so I will test HW serial and serout/in. Hopefully with some sort of result, as these are not my modules.

I do have access to a full professional RF spectrum test setup, however without serout/in comms working there is no point using it.

Rob

[tasmod]

At last. Working.

Redesigned pcb's but not reconfigured. Just turned pic sideways for ease of removal and added pads for each pin to facilitate cross connection, although not finally needed.

After making up the boards I wrote the most simple TX/RX routines and connected the 3 pins needed with temporary jumpers. They immediately talked to each other. Replacing the jumpers with the modules and they talked !!!!

There was one change in code that needed to be added but later removal and they still talked although not quite 100%. That was the extra first characters "SSSSSSSSBOB" before the required string to match the serin string of "BOB"


Send code -------------

Include "modedefs.bas" 
DEFINE OSC 10


TRISA = %00000000

CMCON=7

pause 2000

TEST:
    serout PortA.3, T9600,["SSSSSSSBOB"] 
    PAUSE 500
    GOTO TEST  
END

Receive code -----------------------------

Include "modedefs.bas" 
DEFINE OSC 10

TRISA = %11111101       

CMCON=7

relay var PortA.1


low relay

pause 2000

TEST:
    low relay
    pause 100
    serin PortA.2,T9600,["BOB"] 
    high relay
    PAUSE 1000
    GOTO TEST
        
END

Now I need to expand the code to do just what I want and to then add a decent antenna to get the range.

I'm considering a 'Moxon' Rectangle which gives 3dbd gain with excellent f/b ratio fitted directly to modules via short solid wire. It can be made up using UK twin earth cable wire. About 1.5mm copper. It's very small indeed at 123x46mm

Rob

[Demon]

You pause 500 after transmit, but pause 1000 after reception?

Robert