Newbie radio link issue

[George]

Sorry - here it is: http://www.lprs.co.uk/pdf_directory/....3-sept-05.pdf
BTW - if I make a 20MHz board - what size caps do I use with my crystal? I use to use 22pF with 4MHz - does that mean I use 5pF with 20MHz?
cheers

[mister_e]

the recommended cap are listed in your datasheet. usually 22pF is a nice choice.

In theory your SEROUT is good. BUT, to me, you still have to transmit it with the default baudrate.. so it doesn't solve the problem unless you buy the suggested module to reprogram them first.. waste of time and money to me.

BTW @19200 baud, for ANY reliable serial comm, i'll suggest you to use the PIC USART with HSERIN/HSEROUT instead.

[George]

You don't think SEROUT2 running 20MHz could send enough data to change the default setting in the radio module? Is my syntax correct in how I'd send it? If you think that the serout won't do 19200 then I think I'll just cut my losses and try find another module that just works, the manufacturer did say that I could send it back and they would change it in the factory and send it back to me - however they r on the opposite side of the planet!

[mister_e]

Try with DEBUG first. it's probably better. BUT both of them worth a try for sure.

[George]

sweet - will try with debug - is my syntax correct?

SEROUT pin,baud,["ER_CMD#U1"]

sorry - i mean:

DEBUG "ER_CMD#U1"

???
Thanks

[mister_e]

should be good. Don't forget to set the according DEFINEs listed in the manual.

Good luck!

[skimask]

You don't think SEROUT2 running 20MHz could send enough data to change the default setting in the radio module? Is my syntax correct in how I'd send it? If you think that the serout won't do 19200 then I think I'll just cut my losses and try find another module that just works, the manufacturer did say that I could send it back and they would change it in the factory and send it back to me - however they r on the opposite side of the planet!

If you've got a few extra crystals handy (and assume that you just happen to have the right values ), how about tell the compiler you're using 2400 baud with 4mhz, but actually use a 32mhz. The compiler won't know the difference and you'll be running at 19,200.
But since you're running a 16F series, you're probably limited to 20mhz (depending), so maybe, tell the compiler you're running 4mhz with 9600 baud, and actually use 8mhz, to which you'll get 19,200 baud...
But there I go thinking again...gotta stop that...

[mister_e]

yes, tricking the way you said should work... but i don't see any advantage here.

[skimask]

yes, tricking the way you said should work... but i don't see any advantage here.

According to the manual, when using SERIN/SEROUT, 4mhz only get you 2400 baud reliably. Tricking the compiler, a person should be able to get 4800 on 8mhz, 9600 on 16mhz, etc. without too much worry...that's all.
I'm using this sort of thing to work my comm's at 38,400 with a bit more accuracy (I think). My program, running at 40mhz, didn't seem to want to run when compiled with DEFINE OSC 40 and SEROUT2...6 to get 38,400 comm's. But, if I defined 4mhz and SEROUT2...254, and just pretended to be using 3,840bps, it worked like a champ. I dunno, maybe the timing was just off that one or two extra microseconds or something...

[George]

How do I know if I transmit the data inverted or true? What's most likely? Cheers