Topics

The Digital 49er and the Experiments Board

N5IB
 

Yesterday I received the LCD display and rotary encoder I'd ordered to try building the VFO part of the project  in March 2016 QST (p39). My intent was to use an Experimenters Board to hold the DDS and the NANO.

I laid out that board some months ago, before the QST article appeared, and Arduino-naive as I am, I did a foolish thing.

I didn't realize that digital pins 2 and 3 are interrupt pins, and went ahead and used them as part of the DDS control line pins. But the rotary encoder as used in the QST project needs to employ the interrupts.

Fortunately I did the layout in such a way that traces can be easily cut and jumpers added to re-route the needed DDS lines to other pins. And digital pins 2 through 5 are brought out to pads for external connection.

So it can be done, just a little less convenient than could be. I'd be interested to hear if anyone has undertaken, or is considering, that QST project, with or without using the Experimenters Board.

Just for reference, the software provided with the article uses the following pins:
(those marked with *  are free and unassigned on the Experimenters Board)

*D8:   DDS W_CLK

*D9:   DDS Freq_Update

*D10: DDS data

*D11: DDS RESET


*D12: 49er T/R pin

*D13 apparently reserved:


D2:   Rotary encoder "D"

D3:   Rotary encoder "C"

D4:   Rotary encoder PB switch


*A4: LCD SDA (used as digital)

*A5: LCD SCL (used as digital)


*A7:  used as analog, reserved for new features


It's worth noting that the DDS module used in the article is an AD-9850 of our "Type-2" nomenclature. It is run on 3.3 V, however, using a pair of diodes from the 5V supply powering the NANO and the LCD.


73,

Jim, N5IB



Orville Jones <alwanbi@...>
 

Jim,
I just received my March QST yesterday and today I am ordering all the parts I need for the transceiver. I also have a Experimenter's Board that I have not used yet. I am willing to follow along with your experiments once I receive all my parts.
 
Al, N8WQ
 

To: PHSNA@...
From: PHSNA@...
Date: Wed, 9 Mar 2016 08:31:06 -0800
Subject: [PHSNA] The Digital 49er and the Experiments Board



Yesterday I received the LCD display and rotary encoder I'd ordered to try building the VFO part of the project  in March 2016 QST (p39). My intent was to use an Experimenters Board to hold the DDS and the NANO.

I laid out that board some months ago, before the QST article appeared, and Arduino-naive as I am, I did a foolish thing.

I didn't realize that digital pins 2 and 3 are interrupt pins, and went ahead and used them as part of the DDS control line pins. But the rotary encoder as used in the QST project needs to employ the interrupts.

Fortunately I did the layout in such a way that traces can be easily cut and jumpers added to re-route the needed DDS lines to other pins. And digital pins 2 through 5 are brought out to pads for external connection.

So it can be done, just a little less convenient than could be. I'd be interested to hear if anyone has undertaken, or is considering, that QST project, with or without using the Experimenters Board.

Just for reference, the software provided with the article uses the following pins:
(those marked with *  are free and unassigned on the Experimenters Board)

*D8:   DDS W_CLK
*D9:   DDS Freq_Update
*D10: DDS data
*D11: DDS RESET


*D12: 49er T/R pin
*D13 apparently reserved:



D2:   Rotary encoder "D"
D3:   Rotary encoder "C"
D4:   Rotary encoder PB switch


*A4: LCD SDA (used as digital)

*A5: LCD SCL (used as digital)



*A7:  used as analog, reserved for new features



It's worth noting that the DDS module used in the article is an AD-9850 of our "Type-2" nomenclature. It is run on 3.3 V, however, using a pair of diodes from the 5V supply powering the NANO and the LCD.


73,
Jim, N5IB

 

K5ESS
 

Don’t cut any traces yet.  You can use other unused pins for the rotary encoder.  I’ll post the code later today.

Mike K5ESS

 

From: PHSNA@... [mailto:PHSNA@...]
Sent: Wednesday, March 09, 2016 10:46 AM
To: PHSNA@...
Subject: RE: [PHSNA] The Digital 49er and the Experiments Board

 

 

Jim,
I just received my March QST yesterday and today I am ordering all the parts I need for the transceiver. I also have a Experimenter's Board that I have not used yet. I am willing to follow along with your experiments once I receive all my parts.
 
Al, N8WQ
 


To: PHSNA@...
From: PHSNA@...
Date: Wed, 9 Mar 2016 08:31:06 -0800
Subject: [PHSNA] The Digital 49er and the Experiments Board



Yesterday I received the LCD display and rotary encoder I'd ordered to try building the VFO part of the project  in March 2016 QST (p39). My intent was to use an Experimenters Board to hold the DDS and the NANO.

I laid out that board some months ago, before the QST article appeared, and Arduino-naive as I am, I did a foolish thing.

I didn't realize that digital pins 2 and 3 are interrupt pins, and went ahead and used them as part of the DDS control line pins. But the rotary encoder as used in the QST project needs to employ the interrupts.

Fortunately I did the layout in such a way that traces can be easily cut and jumpers added to re-route the needed DDS lines to other pins. And digital pins 2 through 5 are brought out to pads for external connection.

So it can be done, just a little less convenient than could be. I'd be interested to hear if anyone has undertaken, or is considering, that QST project, with or without using the Experimenters Board.

Just for reference, the software provided with the article uses the following pins:
(those marked with *  are free and unassigned on the Experimenters Board)

*D8:   DDS W_CLK
*D9:   DDS Freq_Update
*D10: DDS data
*D11: DDS RESET


*D12: 49er T/R pin
*D13 apparently reserved:



D2:   Rotary encoder "D"
D3:   Rotary encoder "C"
D4:   Rotary encoder PB switch


*A4: LCD SDA (used as digital)

*A5: LCD SCL (used as digital)



*A7:  used as analog, reserved for new features



It's worth noting that the DDS module used in the article is an AD-9850 of our "Type-2" nomenclature. It is run on 3.3 V, however, using a pair of diodes from the 5V supply powering the NANO and the LCD.


73,
Jim, N5IB

 

N5IB
 

Great, Mike!

I was hoping someone smarter than me could figure it out...
Are you able to reroute the interrupts, or handle the encoder without needing interrupts?

I took one of the old proto-run Experimenter Boards and prepped it by cutting the four traces to the DDS, but I will set aside another one to use your version. These are some of the left-overs with a few wrong sized holes, but otherwise workable.

Jim, N5IB


---In PHSNA@..., <k5ess.nothdurft@...> wrote :

Don’t cut any traces yet.  You can use other unused pins for the rotary encoder.  I’ll post the code later today.

Mike K5ESS

 

 

K5ESS
 

Just uploaded Arduino sketch and accompanying interconnect diagram for using the Experimenters Board as a VFO with a rotary encoder and LCD display.  Interrupts were moved to pins A0 and A1 for the encoder.   Pin A2 is used for the frequency step size push button switch on the encoder.  Provision is made for an IF offset switch on pin A3 (not implemented in the posted sketch).  LCD connections are to adjacent pins on the Experimenters Board (D6 – D10 and D12).  I plan on a right angle header on the bottom of the board for these connections.  Sketch is for AD9850.  Need to change clock frequency for AD9851.  In the interest of full honest disclosure the sketch was not tested on an experimenters board but on a prototype board using the connections shown in the PDF file.

Mike K5ESS

 

From: PHSNA@... [mailto:PHSNA@...]
Sent: Wednesday, March 09, 2016 12:17 PM
To: PHSNA@...
Subject: RE: [PHSNA] The Digital 49er and the Experiments Board

 

 

Great, Mike!

I was hoping someone smarter than me could figure it out...
Are you able to reroute the interrupts, or handle the encoder without needing interrupts?

I took one of the old proto-run Experimenter Boards and prepped it by cutting the four traces to the DDS, but I will set aside another one to use your version. These are some of the left-overs with a few wrong sized holes, but otherwise workable.

Jim, N5IB

---In PHSNA@..., <k5ess.nothdurft@...> wrote :

Don’t cut any traces yet.  You can use other unused pins for the rotary encoder.  I’ll post the code later today.

Mike K5ESS

 

 

K5ESS
 

Added a sketch that has IF offset capability using the Experimenters Board.  Requires a contact closure or logic ground to invoke the offset.  IF offset value in sketch should be a positive number if LO is below signal freq. and a negative number if above.  When the offset is positive and the value of the offset is greater than the minimum frequency set in the sketch the DDS output will go to zero and then wrap around to give frequencies equal to |signal freq – IF offset|  for example if you set the IF Offset to 4000000 and you set the signal frequency to 3500000 the DDS will output 500000 Hz.   Should be fairly easy to modify the sketch to so that at a given frequency the LO switches from below the signal frequency to above.  Be glad to do that if anyone would like that.

Mike K5ESS

 

From: PHSNA@... [mailto:PHSNA@...]
Sent: Wednesday, March 09, 2016 2:14 PM
To: PHSNA@...
Subject: RE: [PHSNA] The Digital 49er and the Experiments Board

 

 

Just uploaded Arduino sketch and accompanying interconnect diagram for using the Experimenters Board as a VFO with a rotary encoder and LCD display.  Interrupts were moved to pins A0 and A1 for the encoder.   Pin A2 is used for the frequency step size push button switch on the encoder.  Provision is made for an IF offset switch on pin A3 (not implemented in the posted sketch).  LCD connections are to adjacent pins on the Experimenters Board (D6 – D10 and D12).  I plan on a right angle header on the bottom of the board for these connections.  Sketch is for AD9850.  Need to change clock frequency for AD9851.  In the interest of full honest disclosure the sketch was not tested on an experimenters board but on a prototype board using the connections shown in the PDF file.

Mike K5ESS

 

From: PHSNA@... [mailto:PHSNA@...]
Sent: Wednesday, March 09, 2016 12:17 PM
To: PHSNA@...
Subject: RE: [PHSNA] The Digital 49er and the Experiments Board

 

 

Great, Mike!

I was hoping someone smarter than me could figure it out...
Are you able to reroute the interrupts, or handle the encoder without needing interrupts?

I took one of the old proto-run Experimenter Boards and prepped it by cutting the four traces to the DDS, but I will set aside another one to use your version. These are some of the left-overs with a few wrong sized holes, but otherwise workable.

Jim, N5IB


---In PHSNA@..., <k5ess.nothdurft@...> wrote :

Don’t cut any traces yet.  You can use other unused pins for the rotary encoder.  I’ll post the code later today.

Mike K5ESS

 

 

K5ESS
 

I just realized I didn’t completely answer the mail on the original post.  Although the sketches I posted are based on the same original code by AD7C as the QST article they do not include the modifications in the QST article.  I’ll fix that and post additional sketch(s).

Mike K5ESS

 

From: PHSNA@... [mailto:PHSNA@...]
Sent: Wednesday, March 09, 2016 9:40 PM
To: PHSNA@...
Subject: RE: [PHSNA] The Digital 49er and the Experiments Board

 

 

Added a sketch that has IF offset capability using the Experimenters Board.  Requires a contact closure or logic ground to invoke the offset.  IF offset value in sketch should be a positive number if LO is below signal freq. and a negative number if above.  When the offset is positive and the value of the offset is greater than the minimum frequency set in the sketch the DDS output will go to zero and then wrap around to give frequencies equal to |signal freq – IF offset|  for example if you set the IF Offset to 4000000 and you set the signal frequency to 3500000 the DDS will output 500000 Hz.   Should be fairly easy to modify the sketch to so that at a given frequency the LO switches from below the signal frequency to above.  Be glad to do that if anyone would like that.

Mike K5ESS

 

From: PHSNA@... [mailto:PHSNA@...]
Sent: Wednesday, March 09, 2016 2:14 PM
To: PHSNA@...
Subject: RE: [PHSNA] The Digital 49er and the Experiments Board

 

 

Just uploaded Arduino sketch and accompanying interconnect diagram for using the Experimenters Board as a VFO with a rotary encoder and LCD display.  Interrupts were moved to pins A0 and A1 for the encoder.   Pin A2 is used for the frequency step size push button switch on the encoder.  Provision is made for an IF offset switch on pin A3 (not implemented in the posted sketch).  LCD connections are to adjacent pins on the Experimenters Board (D6 – D10 and D12).  I plan on a right angle header on the bottom of the board for these connections.  Sketch is for AD9850.  Need to change clock frequency for AD9851.  In the interest of full honest disclosure the sketch was not tested on an experimenters board but on a prototype board using the connections shown in the PDF file.

Mike K5ESS

 

From: PHSNA@... [mailto:PHSNA@...]
Sent: Wednesday, March 09, 2016 12:17 PM
To: PHSNA@...
Subject: RE: [PHSNA] The Digital 49er and the Experiments Board

 

 

Great, Mike!

I was hoping someone smarter than me could figure it out...
Are you able to reroute the interrupts, or handle the encoder without needing interrupts?

I took one of the old proto-run Experimenter Boards and prepped it by cutting the four traces to the DDS, but I will set aside another one to use your version. These are some of the left-overs with a few wrong sized holes, but otherwise workable.

Jim, N5IB



---In PHSNA@..., <k5ess.nothdurft@...> wrote :

Don’t cut any traces yet.  You can use other unused pins for the rotary encoder.  I’ll post the code later today.

Mike K5ESS

 

 

N5IB
 

Thanks, Mike, for those sketches. I'm in the process of doing one system "as written" in QST, then will set up another one using your version of the code.

Can I ask one more bit of advice and counsel...

The LCD display called out in the QST article was one that has a little daughterboard attached to provide an I2C interface. Was that one of the modifications in the article you mentioned? Could you guide us through the code changes needed to use that display?

Jim, N5IB

 

 

Norberto Modanesi
 


Thanks. 73
 

----- Original Message -----
Sent: Thursday, March 10, 2016 11:58 AM
Subject: RE: [PHSNA] The Digital 49er and the Experiments Board

 

Look in the K5ESS folder.

Mike K5ESS

From: PHSNA@... [mailto:PHSNA@...]
Sent: Thursday, March 10, 2016 6:12 AM
To: PHSNA@...
Subject: Re: [PHSNA] The Digital 49er and the Experiments Board

 



Where did you upload it?

73

----- Original Message -----

To: PHSNA@...

Sent: Wednesday, March 09, 2016 5:13 PM

Subject: RE: [PHSNA] The Digital 49er and the Experiments Board

 

Just uploaded Arduino sketch and accompanying interconnect diagram for using the Experimenters Board as a VFO with a rotary encoder and LCD display.  Interrupts were moved to pins A0 and A1 for the encoder.   Pin A2 is used for the frequency step size push button switch on the encoder.  Provision is made for an IF offset switch on pin A3 (not implemented in the posted sketch).  LCD connections are to adjacent pins on the Experimenters Board (D6 – D10 and D12).  I plan on a right angle header on the bottom of the board for these connections.  Sketch is for AD9850.  Need to change clock frequency for AD9851.  In the interest of full honest disclosure the sketch was not tested on an experimenters board but on a prototype board using the connections shown in the PDF file.

Mike K5ESS

From: PHSNA@... [mailto:PHSNA@...]
Sent: Wednesday, March 09, 2016 12:17 PM
To: PHSNA@...
Subject: RE: [PHSNA] The Digital 49er and the Experiments Board

 

Great, Mike!

I was hoping someone smarter than me could figure it out...
Are you able to reroute the interrupts, or handle the encoder without needing interrupts?

I took one of the old proto-run Experimenter Boards and prepped it by cutting the four traces to the DDS, but I will set aside another one to use your version. These are some of the left-overs with a few wrong sized holes, but otherwise workable.

Jim, N5IB


---In PHSNA@..., <k5ess.nothdurft@...> wrote :

Don’t cut any traces yet.  You can use other unused pins for the rotary encoder.  I’ll post the code later today.

Mike K5ESS

 

 

Tim
 

I think, always dangerous, that this setup, experimenter boadr, Nanao, and DDS would work with quite a few QRP crystal bound rigs. MFJ cubs, some rigs from GQRP etc.
Great experiments lie ahead!!
Tim 

K5ESS
 

Even old boatanchors can benefit.  See  http://www.wa1ffl.com/VFO_driver_amp.pdf

Mike K5ESS

 

From: PHSNA@... [mailto:PHSNA@...]
Sent: Thursday, March 10, 2016 1:53 PM
To: PHSNA@...
Subject: [PHSNA] Re: The Digital 49er and the Experiments Board

 

 

I think, always dangerous, that this setup, experimenter boadr, Nanao, and DDS would work with quite a few QRP crystal bound rigs. MFJ cubs, some rigs from GQRP etc.

Great experiments lie ahead!!

Tim 

K5ESS
 

Jim,

The QST sketch has quite a few bells and whistles not included in the sketches I uploaded.  My sketches are pretty simple and straightforward.  You just use the rotary encoder to set a frequency between the limits you hard code in the sketch (e.g. 1 MHz lower bound and 30 MHz upper bound)  and with the encoder push button you can change the frequency step size from 10 Hz to 1 MHz. 

Yes, the use of the I2C bus for the display is one of the modifications I was referring to.  I can modify my sketches to use this type of display if that was what you were asking.  I also intend to modify the QST article code to use the interrupt scheme that allows the Experimenter Board to be used without modification.  Might take me a couple of days.  

Mike K5ESS

 

From: PHSNA@... [mailto:PHSNA@...]
Sent: Thursday, March 10, 2016 9:09 AM
To: PHSNA@...
Subject: RE: [PHSNA] The Digital 49er and the Experiments Board

 

 

Thanks, Mike, for those sketches. I'm in the process of doing one system "as written" in QST, then will set up another one using your version of the code.

Can I ask one more bit of advice and counsel...

The LCD display called out in the QST article was one that has a little daughterboard attached to provide an I2C interface. Was that one of the modifications in the article you mentioned? Could you guide us through the code changes needed to use that display?

Jim, N5IB

 

 

 

Tim
 

Tnx, I have been looking for a buffer amp for my Drake Twins.
I have older much less stable DDS for it now but would like to upgrade.
This will really help.
Tim