[aprssig] RFM22B UHF Transceiver Module

John Wiseman john.wiseman at cantab.net
Wed Dec 12 04:21:29 EST 2012


Bob,

I've had another look through the module spec, and it seems it can do FSK as
well as GFSK  so in thory it could be compatible with current common on-air
signals. But that would mean disabling the on-chip packet handling, and
doing all the HDLC bit level operation in software. The PIC has enough power
to do this for a 1200 link, but I'm not sure it it could cope with 9600.

John 

-----Original Message-----
From: aprssig-bounces at tapr.org [mailto:aprssig-bounces at tapr.org] On Behalf
Of John Wiseman
Sent: 11 December 2012 23:03
To: 'TAPR APRS Mailing List'
Subject: Re: [aprssig] RFM22B UHF Transceiver Module

Bob.

Depends what you mean. The interface into the TNC from the application is
ax.25. The on-air modulation and packet formats are not the same as current
TNC's. So you need an RFM module at each end of a link, but it should work
with any KISS-enabled application.

John

 

-----Original Message-----
From: aprssig-bounces at tapr.org [mailto:aprssig-bounces at tapr.org] On Behalf
Of Robert Bruninga
Sent: 11 December 2012 21:51
To: TAPR APRS Mailing List
Subject: Re: [aprssig] RFM22B UHF Transceiver Module

On Tue, Dec 11, 2012 at 2:13 PM, John Wiseman <john.wiseman at cantab.net>
wrote:
> At the moment I'm running with 9600 GFSK, which is done by the module.

I assume you are not making it AX.25 compatible at this time.  That woule be
an entire additional leverl of effort to make it compatible with existing
APRS radios and their 9600 GMSK of AX.25...  bob

_______________________________________________
aprssig mailing list
aprssig at tapr.org
https://www.tapr.org/cgi-bin/mailman/listinfo/aprssig


_______________________________________________
aprssig mailing list
aprssig at tapr.org
https://www.tapr.org/cgi-bin/mailman/listinfo/aprssig





More information about the aprssig mailing list