> I have been trying to decipher a communications protocol for some time now
> with only limited success. It is used for communicating data between a
> microphone and the body of a radio transceiver (Kenwood D710 for amateur
> radio). All communication occurs on a single wire; there are not separate
> data and clock lines.  In terms of the operation of the radio, there
> really
> isn't any need for bi-directional communication... data only needs to flow
> from the microphone to the radio.
>
> I created a webpage that has the oscilloscope screen shots for the data
> captured flowing between the microphone and the radio.  I have found how
> the data is encoded, but what I haven't been able to decipher is the
> handshaking that seems to be occurring between the two.
>
> If you have the time and inclination to take a look at this, I would
> appreciate any suggestions that you might have.  Someone told me that they
> have seen this before, but they are either unwilling or unable to tell me
> where or what it's called.  They also suggested that a PIC lacked the
> horsepower needed to communicate using this protocol, but based on what
> I'm
> seeing on the scope, this seems to me to be very unlikely.
>
> The web page with the details is at:  http://www.johnhansen.org
>
> Thanks in advance for any ideas!

>On Fri, July 6, 2012 3:15 pm, John Hansen wrote:
>> I have been trying to decipher a communications protocol for some time now
>> with only limited success. It is used for communicating data between a
>> microphone and the body of a radio transceiver (Kenwood D710 for amateur
>> radio). All communication occurs on a single wire; there are not separate
>> data and clock lines.  In terms of the operation of the radio, there
>> really
>> isn't any need for bi-directional communication... data only needs to flow
>> from the microphone to the radio.
>>
>> I created a webpage that has the oscilloscope screen shots for the data
>> captured flowing between the microphone and the radio.  I have found how
>> the data is encoded, but what I haven't been able to decipher is the
>> handshaking that seems to be occurring between the two.
>>
>> If you have the time and inclination to take a look at this, I would
>> appreciate any suggestions that you might have.  Someone told me that they
>> have seen this before, but they are either unwilling or unable to tell me
>> where or what it's called.  They also suggested that a PIC lacked the
>> horsepower needed to communicate using this protocol, but based on what
>> I'm
>> seeing on the scope, this seems to me to be very unlikely.
>>
>> The web page with the details is at:  http://www.johnhansen.org
>>
>> Thanks in advance for any ideas!
>
>I have not seen this protocol before, but this sure seems like a good
>application for the "logic" analyzer: <http://www.saleae.com/logic/> This
>has the combination of very deep memory and fast enough sampling so you
>should be able to record and decode the protocol.  I can loan you mine for
>a short time if you're in the area (near Austin, TX), but the logic is
>relatively cheap- just buy one!
>
>(just a happy user of the logic)
>
>
>

> On Fri, July 6, 2012 3:15 pm, John Hansen wrote:
>> I have been trying to decipher a communications protocol for some time now
>> with only limited success. It is used for communicating data between a
>> microphone and the body of a radio transceiver (Kenwood D710 for amateur
>> radio). All communication occurs on a single wire; there are not separate
>> data and clock lines.  In terms of the operation of the radio, there
>> really
>> isn't any need for bi-directional communication... data only needs to flow
>> from the microphone to the radio.
>>
>> I created a webpage that has the oscilloscope screen shots for the data
>> captured flowing between the microphone and the radio.  I have found how
>> the data is encoded, but what I haven't been able to decipher is the
>> handshaking that seems to be occurring between the two.
>>
>> If you have the time and inclination to take a look at this, I would
>> appreciate any suggestions that you might have.  Someone told me that they
>> have seen this before, but they are either unwilling or unable to tell me
>> where or what it's called.  They also suggested that a PIC lacked the
>> horsepower needed to communicate using this protocol, but based on what
>> I'm
>> seeing on the scope, this seems to me to be very unlikely.
>>
>> The web page with the details is at:  http://www.johnhansen.org
>>
>> Thanks in advance for any ideas!
> I have not seen this protocol before, but this sure seems like a good
> application for the "logic" analyzer: <http://www.saleae.com/logic/> This
> has the combination of very deep memory and fast enough sampling so you
> should be able to record and decode the protocol.  I can loan you mine for
> a short time if you're in the area (near Austin, TX), but the logic is
> relatively cheap- just buy one!
>
> (just a happy user of the logic)
>
>
>
> Matt Bennett
> Just outside of Austin, TX
> 30.51,-97.91
>
> The views I express are my own, not that of my employer, a large
> multinational corporation that you are familiar with.

> Most probably this bus uses open-drain drivers with a pull-up resistor.
>
> Add a low-value resistor in series with the line to exacerbate any
> voltage drop. This way you can connect one of your scope's probe to each
> side of the resistor and then you will know when it is the master and
> when it is the the microphone that are pulling the line low.
>
> Possibly the microphone is pulling the line low after it sees the host
> pulling it low. When the host releases the line, the microphone keeps it
> low for the time it wishes, signaling a zero or a one.
>
> If that's true, you will see small "steps" in the signal when the host
> releases the line.
>
>
> Isaac
>
>
>
> Em 6/7/2012 17:41, Matt Bennett escreveu:
> > On Fri, July 6, 2012 3:15 pm, John Hansen wrote:
> >> I have been trying to decipher a communications protocol for some time
> now
> >> with only limited success. It is used for communicating data between a
> >> microphone and the body of a radio transceiver (Kenwood D710 for amateur
> >> radio). All communication occurs on a single wire; there are not
> separate
> >> data and clock lines.  In terms of the operation of the radio, there
> >> really
> >> isn't any need for bi-directional communication... data only needs to
> flow
> >> from the microphone to the radio.
> >>
> >> I created a webpage that has the oscilloscope screen shots for the data
> >> captured flowing between the microphone and the radio.  I have found how
> >> the data is encoded, but what I haven't been able to decipher is the
> >> handshaking that seems to be occurring between the two.
> >>
> >> If you have the time and inclination to take a look at this, I would
> >> appreciate any suggestions that you might have.  Someone told me that
> they
> >> have seen this before, but they are either unwilling or unable to tell
> me
> >> where or what it's called.  They also suggested that a PIC lacked the
> >> horsepower needed to communicate using this protocol, but based on what
> >> I'm
> >> seeing on the scope, this seems to me to be very unlikely.
> >>
> >> The web page with the details is at:  http://www.johnhansen.org
> >>
> >> Thanks in advance for any ideas!
> > I have not seen this protocol before, but this sure seems like a good
> > application for the "logic" analyzer: <http://www.saleae.com/logic/>
> This
> > has the combination of very deep memory and fast enough sampling so you
> > should be able to record and decode the protocol.  I can loan you mine
> for
> > a short time if you're in the area (near Austin, TX), but the logic is
> > relatively cheap- just buy one!
> >
> > (just a happy user of the logic)
> >
> >
> >
> > Matt Bennett
> > Just outside of Austin, TX
> > 30.51,-97.91
> >
> > The views I express are my own, not that of my employer, a large
> > multinational corporation that you are familiar with.
>
>