Read Data via Data Connector From Radio?

[PeterGV]

Does anybody have any info that can share about how to get data from the radio while it's scanning and landed on a channel, sort of like shown on an XTVA?

I'd like to be able to read the data from the radio display via the data pins on the side... does anybody have any info on how the data appears on which pins and in what format??

Thanks,

Peter
K1PGV

[Mfire39]

Ummm, what?

[PeterGV]

Sorry... was that not clear?

I'd like to know if anyone happens to know how to read the currently landed channel information, via the data port connection on the side of the radio.

This data must be available somehow, as it's shown (for example) on the HHCH when the radio is in an XTVA.

I'm asking if anyone knows which pins, what format the data is provided in, whether there's any protocol involved, and what one might need to do to read that data.

Is that more clear?

Peter
K1PGV

[tvsjr]

No, that wasn't. This would be more clear:

Hi. I've got an XTS5000 VHF Model 3, model X, flashcode Y, firmware Z. I'm trying to find a way to determine what channel the radio is sitting on - for instance, when in scan. I know an XTVA with a handheld control head will display the channel information - would there be any way for me to intercept that data? I'm looking for help with wiring, protocol, etc. I will not be using an XTVA in my application - I'll be connecting directly to the side of the radio.

And the answer would be: Not likely... the HHCH communicates bidirectionally with the radio - the radio doesn't just barf out channel information. You'd need to do some pretty advanced work to get the radio to talk to you, and you'd have to reverse-engineer the SB9600 protocol which wouldn't make Motorola happy in the least.

[PeterGV]

Sorry... it's been a long weekend writing code... my brain must be on "C" and off "English".

I DO appreciate the answer. Knowing the name of the protocol is extremely helpful, as that allowed me to search the board for other posts on this topic. I also discovered that the protocl is patented. The physical layer seems pretty simple (it's a serial buswith a "busy" line, something almost any MCU could talk to, I would guess).

Again, thanks very much for the help,

Peter
K1PGV

[tvsjr]

Assuming you're indeed playing with an XTS5000, you can also talk to it like a modem using standard AT commands via the programming/flash cable. Some commands are reasonably standard, some aren't. Be careful... it wouldn't shock me to find that some commands will brick the radio.

[xmo]

I did a little project along these lines as an experiment.

I took an Astro Spectra. I connected a RIB to the data bus. I connected that to a PC serial port so I can monitor the SB9600 data sent to the head from the radio.

To do this you must connect only the receive data pin and ground. If you use a regular serial cable the hardware handshake pins from the PC will cause the RIB to busy the data bus.

I also inserted a serial protocol analyzer inline to see all of the data. From there, it wasn't too hard to decipher. I then wrote a simple program for the PC that displays the unit ID and soft ID data that the radio decodes from a P25 channel [the radio has the H14 option].

There's no reason why you couldn't use the same process to tell a computer program which channel the radio scan stopped on.

Good clean fun.

[mancow]

I did some of this a few years ago and I think I may have posted some of the info. I was able to control certain things on an analog spectra using a RIB connected to the pc to read and send data to the radio. I remember turning on and off the DIR function and maybe dimming the display too.

[PeterGV]

I did some of this a few years ago and I think I may have posted some of the info. I was able to control certain things on an analog spectra using a RIB connected to the pc to read and send data to the radio.

That's what I'd like to do as well. To be absolutely clear, this is just a hobby activity, I'm not trying to make a product. I only have Astro25 portables, not mobiles, so I can't really think of a good way to watch what's going on between the radio and (for example) the XTVA.

The way I understand it, the initial protocol the radio uses is SB9600 (which consists entirely of sequences of 1-byte "packets"). The controller than switches the radio to "SBEP" mode, which allows for variable-length messages. According to my Google research, it sppears that Moto uses the SBEP protocol for in wide variety of devices, including cellular phones.

The SBEP protocol sequence the radio uses to display information on the control head is public (it's disclosed in the patent):

Radio......Control Head
RESET -->
RQ DISPLAY -->
<-- SHOW DISPLAY
DISPLAY IS -->
<-- ACK

Of course, the specific byte sequence comprising those messages isn't exactly clear.

Dig we must,

Peter
K1PGV