Band data interface #hobbypcb


ccoles326@...
 

Hello All,
I am trying to make an interface to read the 12C data output and present this as a voltage. It is simply a 12C DAC board and a 3.3v Supply, the idea was inspired by other posts on this group.

But the voltage output remains stubbornly at 1.6v and does not respond to band changes from the radio. It is all connected up as shown in the image below.

Would anybody know why it does not work? 

Any advice, hints or suggestions would be very welcome.



Many thanks in advance,
Chris
M0XFL


Kevin Larcombe
 

Hi Chris,

The I2C data out of the radio needs to be read by something like a PIC or some other microcontroller, that would then communicate with the DAC to set the output voltage or maybe a simpler R2R ladder DAC. The difficult part is reverse engineering the I2C data from the radio, not being a digital person myself I have not attempted it. (Although I have thought about trying)

I'm sure there is probably someone around here who has already looked at the I2C from the radio.

Kevin GW0PUH


From: EladSDR@groups.io <EladSDR@groups.io> on behalf of ccoles326@... <ccoles326@...>
Sent: 20 February 2021 19:59
To: EladSDR@groups.io <EladSDR@groups.io>
Subject: [EladSDR] Band data interface #hobbypcb
 
Hello All,
I am trying to make an interface to read the 12C data output and present this as a voltage. It is simply a 12C DAC board and a 3.3v Supply, the idea was inspired by other posts on this group.

But the voltage output remains stubbornly at 1.6v and does not respond to band changes from the radio. It is all connected up as shown in the image below.

Would anybody know why it does not work? 

Any advice, hints or suggestions would be very welcome.



Many thanks in advance,
Chris
M0XFL


Andreas Rehberg
 

Looks ok for me.. though you are somewhat thrifty on parts.. ;-)
 
the pullups on the MCP4725 are active!?
 
you might want to have a look at the QSF-06 manual (if not already done).. then check the pins of the 9 pin plug.. 'from the rear' is maybe ambiguous.. there are usually numbers engraved which is more reliable..
 
73, Andy, DF4WC
 
 
Gesendet: Samstag, 20. Februar 2021 um 20:59 Uhr
Von: ccoles326@...
An: EladSDR@groups.io
Betreff: [EladSDR] Band data interface #hobbypcb
Hello All,
I am trying to make an interface to read the 12C data output and present this as a voltage. It is simply a 12C DAC board and a 3.3v Supply, the idea was inspired by other posts on this group.

But the voltage output remains stubbornly at 1.6v and does not respond to band changes from the radio. It is all connected up as shown in the image below.

Would anybody know why it does not work? 

Any advice, hints or suggestions would be very welcome.



Many thanks in advance,
Chris
M0XFL


ccoles326@...
 

Hello, thank you for the good advice.
I have the above circuit working when connected to my Arduino Uno. I can send it a number, and change the voltage output of the DAC as expected. All good fun.

The DAC is powered up correctly when connected to the Duo radio, but it is unable to decode the IC2 data. So I guess I need to program a different conversion table into the DAC?

I was kinda hoping somebody had already worked out how to read the DUO IC2 data and map this to voltages in the DAC. Always worth a try.

I will keep searching for the answer and try to work this out. If I do, I will share it here.

With best regards,
Chris M0XFL


Simon
 

Hi

Have a look on the hermes lite 2 group

Its been done there..

Maybe not exactly the same, but FULL of ideas..

Mag loop Simon g0zen


Kevin Larcombe
 

Chris,

I would be very interested in your findings. I had intended to hook up my scope to the Duo and see if I could reverse engineer the I2C band data. I play about with Arduino but I am more of an analogue person.

I had intended to use the Arduino as an R2R DAC if I could make sense of the I2C data.

Kevin GW0PUH

On 22 Feb 2021, at 19:54, ccoles326@... wrote:
Hello, thank you for the good advice.
I have the above circuit working when connected to my Arduino Uno. I can send it a number, and change the voltage output of the DAC as expected. All good fun.

The DAC is powered up correctly when connected to the Duo radio, but it is unable to decode the IC2 data. So I guess I need to program a different conversion table into the DAC?

I was kinda hoping somebody had already worked out how to read the DUO IC2 data and map this to voltages in the DAC. Always worth a try.

I will keep searching for the answer and try to work this out. If I do, I will share it here.

With best regards,
Chris M0XFL


Clint Chron
 

Hi Chris,

 

I don’t think that the eBay Chinese DAC boards are going to work.

 

Here is how I setup my DAC board for use with my Duo.

 

You can get a US made Gravis I2C DAC board from Mouser for about $15 USD.

 

This Chinese setup is cheaper than the Gravis unit and also takes up less space on the circuit board.

 

I used this eBay Chinese DAC board:

https://www.ebay.com/itm/1pcs-MCP4725-I2C-DAC-Breakout-Module-12Bit-Resolution-Arduino-Raspberry-Pi-Red/183649184328?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649

 

I removed the Chinese DAC chip and installed a DAC5571 from Mouser (about $1.50).  Considering the DAC chip is SMT, the install was pretty easy even for my tired eyes.

 

I used a Chinese 5 volt to 3.3 volt converter (measured output at 3.297 VDC):

https://www.ebay.com/itm/5-PCS-DC-5V-to-3-3V-Step-Down-Power-Supply-Module-AMS1117-3-3-LDO-800MA-M330/382781803679?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649

 

Here is what I measured on the I2C output, when I feed I2C signals from my Elad Duo.  It looks like my output is about 0.01 volt low.

 

BAND:              Yaesu Spec     Home-Brew DAC      

160M                0.33                   0.325    

80M                  0.66                   0.648  

60M                  undefined          0.996

49M                  undefined          0.996 

40M                  1.0                     0.996               

30M                  1.3                     1.294                             

25M                  undefined          1.294                            

20M                  1.6                     1.589              

19M                  undefined          1.589               

17M                  2.0                     1.989               

15M                  2.3                     2.285                             

12M                  2.7                     2.685              

11M                  undefined          2.685               

10M                  3.0                     2.993                             

6M                     3.3                    3.287      

      

73

Clint

W7KEC

 

 

 

From: EladSDR@groups.io [mailto:EladSDR@groups.io] On Behalf Of ccoles326@...
Sent: Saturday, February 20, 2021 12:59 PM
To: EladSDR@groups.io
Subject: [EladSDR] Band data interface #hobbypcb

 

Hello All,
I am trying to make an interface to read the 12C data output and present this as a voltage. It is simply a 12C DAC board and a 3.3v Supply, the idea was inspired by other posts on this group.

But the voltage output remains stubbornly at 1.6v and does not respond to band changes from the radio. It is all connected up as shown in the image below.

Would anybody know why it does not work? 

Any advice, hints or suggestions would be very welcome.



Many thanks in advance,
Chris
M0XFL


Andy G4JNT
 

If you're going to be using a uController as part of the interface, it could be worth looking at the serial data out.  It contains the frequency data, so you can derive your band switching from that.   Although there is a lot of bytes kicked out at 115200 baud, it is relatively easy to extract the few containing VFO data and Frequency as they are immediately preceded by the header 0x01 0x31.   
I have just recently made an interface that decodes this data, in order to add an external rotary tuning encoder - to replace the awful tuning knob - as well as a keypad.

Unlike the I2C and SPI connections, the serial data is fully described in an Elad document available on their web page.



On Mon, 22 Feb 2021 at 20:07, Kevin Larcombe <kevlarcombe@...> wrote:
Chris,

I would be very interested in your findings. I had intended to hook up my scope to the Duo and see if I could reverse engineer the I2C band data. I play about with Arduino but I am more of an analogue person.

I had intended to use the Arduino as an R2R DAC if I could make sense of the I2C data.

Kevin GW0PUH
On 22 Feb 2021, at 19:54, ccoles326@... wrote:
Hello, thank you for the good advice.
I have the above circuit working when connected to my Arduino Uno. I can send it a number, and change the voltage output of the DAC as expected. All good fun.

The DAC is powered up correctly when connected to the Duo radio, but it is unable to decode the IC2 data. So I guess I need to program a different conversion table into the DAC?

I was kinda hoping somebody had already worked out how to read the DUO IC2 data and map this to voltages in the DAC. Always worth a try.

I will keep searching for the answer and try to work this out. If I do, I will share it here.

With best regards,
Chris M0XFL


Simon
 

Clint

Could not the pcb you designed be modded to do this? The one that i made for bcd output to ussr band filters?

Simon


Clint Chron
 

Sorry Simon,

I am not sure what you are asking. For switching band pass filters attached
to my Duo, I use the SPI output from the Duo - same as what the QSF-6 does.

73
Clint
W7KEC

-----Original Message-----
From: EladSDR@groups.io [mailto:EladSDR@groups.io] On Behalf Of Simon
Sent: Monday, February 22, 2021 1:53 PM
To: EladSDR@groups.io
Subject: Re: [EladSDR] Band data interface #hobbypcb

Clint

Could not the pcb you designed be modded to do this? The one that i made for
bcd output to ussr band filters?

Simon


Clint Chron
 

Here is my design for my board to switch HF band pass filters, using a DAC module.

 

 

73

Clint

W7KEC

 

-----Original Message-----
From: EladSDR@groups.io [mailto:EladSDR@groups.io] On Behalf Of Simon
Sent: Monday, February 22, 2021 1:53 PM
To: EladSDR@groups.io
Subject: Re: [EladSDR] Band data interface #hobbypcb

 

Clint

 

Could not the pcb you designed be modded to do this? The one that i made for bcd output to ussr band filters?

 

Simon

 

 


Andy G4JNT
 

Out of curiosity, I stuck a scope on the SDA and SCL to see what data was coming out of them.  There seems to be just a couple of bytes worth whenever the tuned frequency passes a band threshold.  I was using 1MHz tuning steps and spinning up and down the band to trigger the trace. 

But what's confusing is that I observed no change in the data pattern shown on the scope whatever frequency the radio was tuned to.   I was using the 0dBm output (It's all I ever use)  so does the i2C band data output default to some fixed value when that port is selected?

Couldn't do any captures as I only have an analogue non-storage scope, but setting to one-shot trigger from the SDA pin it clearly showed the unchanging short data burst

Andy  G4JNT


Clint Chron
 

IMHO, the best way to test to 12C output from the Duo is to put a compatible DAC module on the output and look at the voltage readings for the different bands.  One can either buy the Chinese module on eBay and replace the DAC chip ($1.50) from Mouser, or buy the Gravis module for about $15.00.

 

73

Clint

W7KEC

 

From: EladSDR@groups.io [mailto:EladSDR@groups.io] On Behalf Of Andy G4JNT
Sent: Tuesday, February 23, 2021 10:10 AM
To: EladSDR@groups.io
Subject: Re: [EladSDR] Band data interface

 

Out of curiosity, I stuck a scope on the SDA and SCL to see what data was coming out of them.  There seems to be just a couple of bytes worth whenever the tuned frequency passes a band threshold.  I was using 1MHz tuning steps and spinning up and down the band to trigger the trace. 

But what's confusing is that I observed no change in the data pattern shown on the scope whatever frequency the radio was tuned to.   I was using the 0dBm output (It's all I ever use)  so does the i2C band data output default to some fixed value when that port is selected?

Couldn't do any captures as I only have an analogue non-storage scope, but setting to one-shot trigger from the SDA pin it clearly showed the unchanging short data burst

Andy  G4JNT


Andy G4JNT
 

Or just buy the chip.  That microchip device with EE looks quite useful toi have  on the shelf
I don't want to use the I2C interface, just curious to see what it carried.   I have cracked the serial output, decoding in a PIC and that carries actual tuned frequency.  More useful for controlling external hardware

But the I2C data definitely was fixed in my test.   Could do it delivering real RF power, I suppose.
Elad products lack a certain amount of documentation.



On Tue, 23 Feb 2021 at 17:18, Clint Chron <c.kiheiman@...> wrote:

IMHO, the best way to test to 12C output from the Duo is to put a compatible DAC module on the output and look at the voltage readings for the different bands.  One can either buy the Chinese module on eBay and replace the DAC chip ($1.50) from Mouser, or buy the Gravis module for about $15.00.

 

73

Clint

W7KEC

 

From: EladSDR@groups.io [mailto:EladSDR@groups.io] On Behalf Of Andy G4JNT
Sent: Tuesday, February 23, 2021 10:10 AM
To: EladSDR@groups.io
Subject: Re: [EladSDR] Band data interface

 

Out of curiosity, I stuck a scope on the SDA and SCL to see what data was coming out of them.  There seems to be just a couple of bytes worth whenever the tuned frequency passes a band threshold.  I was using 1MHz tuning steps and spinning up and down the band to trigger the trace. 

But what's confusing is that I observed no change in the data pattern shown on the scope whatever frequency the radio was tuned to.   I was using the 0dBm output (It's all I ever use)  so does the i2C band data output default to some fixed value when that port is selected?

Couldn't do any captures as I only have an analogue non-storage scope, but setting to one-shot trigger from the SDA pin it clearly showed the unchanging short data burst

Andy  G4JNT


Kevin Larcombe
 

Clint,

I didn't realise the Duo I2C was directly compatible with driving a DAC, it makes sense but I just assumed it was a proprietary signal that required something to interpret it first.

Thanks for that.

Kevin
GW0PUH 


From: EladSDR@groups.io <EladSDR@groups.io> on behalf of Clint Chron <c.kiheiman@...>
Sent: 23 February 2021 17:18
To: EladSDR@groups.io <EladSDR@groups.io>
Subject: Re: [EladSDR] Band data interface
 

IMHO, the best way to test to 12C output from the Duo is to put a compatible DAC module on the output and look at the voltage readings for the different bands.  One can either buy the Chinese module on eBay and replace the DAC chip ($1.50) from Mouser, or buy the Gravis module for about $15.00.

 

73

Clint

W7KEC

 

From: EladSDR@groups.io [mailto:EladSDR@groups.io] On Behalf Of Andy G4JNT
Sent: Tuesday, February 23, 2021 10:10 AM
To: EladSDR@groups.io
Subject: Re: [EladSDR] Band data interface

 

Out of curiosity, I stuck a scope on the SDA and SCL to see what data was coming out of them.  There seems to be just a couple of bytes worth whenever the tuned frequency passes a band threshold.  I was using 1MHz tuning steps and spinning up and down the band to trigger the trace. 

But what's confusing is that I observed no change in the data pattern shown on the scope whatever frequency the radio was tuned to.   I was using the 0dBm output (It's all I ever use)  so does the i2C band data output default to some fixed value when that port is selected?

Couldn't do any captures as I only have an analogue non-storage scope, but setting to one-shot trigger from the SDA pin it clearly showed the unchanging short data burst

Andy  G4JNT


Clint Chron
 

The 12C interface works good, buy I use the SPI control from the Duo to control my HF band pass filter auto band switching.

 

73

Clint

W7KEC

 

From: EladSDR@groups.io [mailto:EladSDR@groups.io] On Behalf Of Andy G4JNT
Sent: Tuesday, February 23, 2021 10:34 AM
To: EladSDR@groups.io
Subject: Re: [EladSDR] Band data interface

 

Or just buy the chip.  That microchip device with EE looks quite useful toi have  on the shelf

I don't want to use the I2C interface, just curious to see what it carried.   I have cracked the serial output, decoding in a PIC and that carries actual tuned frequency.  More useful for controlling external hardware

 

But the I2C data definitely was fixed in my test.   Could do it delivering real RF power, I suppose.

Elad products lack a certain amount of documentation.

 

 

 

On Tue, 23 Feb 2021 at 17:18, Clint Chron <c.kiheiman@...> wrote:

IMHO, the best way to test to 12C output from the Duo is to put a compatible DAC module on the output and look at the voltage readings for the different bands.  One can either buy the Chinese module on eBay and replace the DAC chip ($1.50) from Mouser, or buy the Gravis module for about $15.00.

 

73

Clint

W7KEC

 

From: EladSDR@groups.io [mailto:EladSDR@groups.io] On Behalf Of Andy G4JNT
Sent: Tuesday, February 23, 2021 10:10 AM
To: EladSDR@groups.io
Subject: Re: [EladSDR] Band data interface

 

Out of curiosity, I stuck a scope on the SDA and SCL to see what data was coming out of them.  There seems to be just a couple of bytes worth whenever the tuned frequency passes a band threshold.  I was using 1MHz tuning steps and spinning up and down the band to trigger the trace. 

But what's confusing is that I observed no change in the data pattern shown on the scope whatever frequency the radio was tuned to.   I was using the 0dBm output (It's all I ever use)  so does the i2C band data output default to some fixed value when that port is selected?

Couldn't do any captures as I only have an analogue non-storage scope, but setting to one-shot trigger from the SDA pin it clearly showed the unchanging short data burst

Andy  G4JNT


Clint Chron
 

It seems to work good.  Unfortunately, the eBay Chinese DAC modules do not seem to work, but they have a nice circuit board.  It only takes a couple of minutes to remove the existing DAC chip and install one that works with the Duo.

 

73

Clint

W7KEC

 

From: EladSDR@groups.io [mailto:EladSDR@groups.io] On Behalf Of Kevin Larcombe
Sent: Tuesday, February 23, 2021 10:38 AM
To: EladSDR@groups.io
Subject: Re: [EladSDR] Band data interface

 

Clint,

 

I didn't realise the Duo I2C was directly compatible with driving a DAC, it makes sense but I just assumed it was a proprietary signal that required something to interpret it first.

 

Thanks for that.

 

Kevin

GW0PUH 

 


From: EladSDR@groups.io <EladSDR@groups.io> on behalf of Clint Chron <c.kiheiman@...>
Sent: 23 February 2021 17:18
To: EladSDR@groups.io <EladSDR@groups.io>
Subject: Re: [EladSDR] Band data interface

 

IMHO, the best way to test to 12C output from the Duo is to put a compatible DAC module on the output and look at the voltage readings for the different bands.  One can either buy the Chinese module on eBay and replace the DAC chip ($1.50) from Mouser, or buy the Gravis module for about $15.00.

 

73

Clint

W7KEC

 

From: EladSDR@groups.io [mailto:EladSDR@groups.io] On Behalf Of Andy G4JNT
Sent: Tuesday, February 23, 2021 10:10 AM
To: EladSDR@groups.io
Subject: Re: [EladSDR] Band data interface

 

Out of curiosity, I stuck a scope on the SDA and SCL to see what data was coming out of them.  There seems to be just a couple of bytes worth whenever the tuned frequency passes a band threshold.  I was using 1MHz tuning steps and spinning up and down the band to trigger the trace. 

But what's confusing is that I observed no change in the data pattern shown on the scope whatever frequency the radio was tuned to.   I was using the 0dBm output (It's all I ever use)  so does the i2C band data output default to some fixed value when that port is selected?

Couldn't do any captures as I only have an analogue non-storage scope, but setting to one-shot trigger from the SDA pin it clearly showed the unchanging short data burst

Andy  G4JNT


Neil Smith G4DBN
 

I wondered if there was a handshake going on, with the DUO sending a "Hello, I have news of a band change" message that then elicits a handshake reply, but that seems daft.  I have one of the SPF-08 units, and the SDA frame content doesn't change when the SPF-08 is connected, but the SPF detects the band change.

The band change on the filter definitely works with the 0dBm output enabled.

Maybe the SDA is just getting an instruction saying "hey, look at the datastream now, I've changed band segments" so the internal CPU can stay asleep until it gets an interrupt from the SCL line, then go back to sleep to reduce diginoise?

Content looks like this:

vertical dotted lines are 1.8 ms apart, symbol period about 129 microseconds

Neil G4DBN


On 23/02/2021 17:09, Andy G4JNT wrote:
Out of curiosity, I stuck a scope on the SDA and SCL to see what data was coming out of them.  There seems to be just a couple of bytes worth whenever the tuned frequency passes a band threshold.  I was using 1MHz tuning steps and spinning up and down the band to trigger the trace. 

But what's confusing is that I observed no change in the data pattern shown on the scope whatever frequency the radio was tuned to.   I was using the 0dBm output (It's all I ever use)  so does the i2C band data output default to some fixed value when that port is selected?

Couldn't do any captures as I only have an analogue non-storage scope, but setting to one-shot trigger from the SDA pin it clearly showed the unchanging short data burst

Andy  G4JNT
_.


Andy G4JNT
 

Glad your findings echo mine - yes your trace capture looks, from memory of a couple of hours ago, to be the same.
Curious.    Course, it could be looking for an ACK, then sends its data - if the specified Microchip device is R/W then it would do  that, and explains our not seeing anything, and all we're seeing is the I2C address being sent.

Can you see if the SPF-08 has :
a)   Any connection to TXD / RXD
b)   It's own microcontroller

Some of the posts here imply the I2C lines go direct to a D/A, which I find a little hard to believe.  That would mandate one particular chip, as there's no standardisation between I2C coding and D/A devices.   
Of course, if Elad do it like that make it , to all intents and purposes, proprietary to their interfaces.

Use the serial data,  it's a lot easier.  



On Tue, 23 Feb 2021 at 18:22, Neil Smith G4DBN <neil@...> wrote:

I wondered if there was a handshake going on, with the DUO sending a "Hello, I have news of a band change" message that then elicits a handshake reply, but that seems daft.  I have one of the SPF-08 units, and the SDA frame content doesn't change when the SPF-08 is connected, but the SPF detects the band change.

The band change on the filter definitely works with the 0dBm output enabled.

Maybe the SDA is just getting an instruction saying "hey, look at the datastream now, I've changed band segments" so the internal CPU can stay asleep until it gets an interrupt from the SCL line, then go back to sleep to reduce diginoise?

Content looks like this:

vertical dotted lines are 1.8 ms apart, symbol period about 129 microseconds

Neil G4DBN


On 23/02/2021 17:09, Andy G4JNT wrote:
Out of curiosity, I stuck a scope on the SDA and SCL to see what data was coming out of them.  There seems to be just a couple of bytes worth whenever the tuned frequency passes a band threshold.  I was using 1MHz tuning steps and spinning up and down the band to trigger the trace. 

But what's confusing is that I observed no change in the data pattern shown on the scope whatever frequency the radio was tuned to.   I was using the 0dBm output (It's all I ever use)  so does the i2C band data output default to some fixed value when that port is selected?

Couldn't do any captures as I only have an analogue non-storage scope, but setting to one-shot trigger from the SDA pin it clearly showed the unchanging short data burst

Andy  G4JNT
_.


Neil Smith G4DBN
 

There is a huge burst of SDA data at startup, which is probably the frequency versus filter number data.

EXCEPT...

When I change the filter settings for band start/end, there is nothing new sent in on SDA to tell the SPF-08 that things have changed, but it obeys the new band settings, so there is something else going on here that I've missed or misinterpreted.

Neil G4DBN

On 23/02/2021 18:22, Neil Smith G4DBN wrote:

I wondered if there was a handshake going on, with the DUO sending a "Hello, I have news of a band change" message that then elicits a handshake reply, but that seems daft.  I have one of the SPF-08 units, and the SDA frame content doesn't change when the SPF-08 is connected, but the SPF detects the band change.

The band change on the filter definitely works with the 0dBm output enabled.

Maybe the SDA is just getting an instruction saying "hey, look at the datastream now, I've changed band segments" so the internal CPU can stay asleep until it gets an interrupt from the SCL line, then go back to sleep to reduce diginoise?