AD9850-ARDUINO Interconnect

Information and discussions on Spectrum Analysis
Jimjrjjrj
Posts: 3
Joined: Sun Apr 14, 2019 2:22 am

Re: AD9850-ARDUINO Interconnect

Postby Jimjrjjrj » Fri Apr 26, 2019 8:54 pm

Mike,

I noted the same fall-off in sine wave output compared to the square wave out on my 9850. I attributed this to the LP filtering used to convert the square wave to a sine wave. I think I saw on a YouTube video somewhere this is "normal"

Jimjrjjrj
WA8MPA
Last edited by Jimjrjjrj on Thu Jan 01, 1970 12:00 am, edited 0 times in total.
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SteveAndrew
Posts: 206
Joined: Thu Nov 16, 2017 11:06 pm
Location: Gold Coast, QLD, Australia

Re: AD9850-ARDUINO Interconnect

Postby SteveAndrew » Sun Apr 28, 2019 2:45 am

Jimjrjjrj wrote:Mike,

I noted the same fall-off in sine wave output compared to the square wave out on my 9850. I attributed this to the LP filtering used to convert the square wave to a sine wave. I think I saw on a YouTube video somewhere this is "normal"

Jimjrjjrj
WA8MPA


Hi Jim and MIke

The fall in amplitude with an increase in frequency is normal. This link explains what is happening.

https://www.maximintegrated.com/en/app- ... vp/id/3853

Devices like the AD9910 have in-built compensation to counteract the sin(x)/x affect.

The analogue output from the DDS is fed back to an uncommitted comparator on the DDS chip. This is used to produce the square wave outputs. There is a trim-pot on the board that is used to set the wave's symmetry, and if not set correctly can result in no output at all - As I spent some time finding out :oops:

Steve

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darec
Posts: 1
Joined: Sun May 05, 2019 1:48 pm

Re: AD9850-ARDUINO Interconnect

Postby darec » Sun May 05, 2019 2:27 pm

Hi guys,

Are you able to connect Trackgen with arduinouno and ad9850 combo to Spectrum Analyser?
Somehow I can not make it working together ie the proper arduino port is listed among other com ports in the Spectrum Analyser soft however when I choose arduino one I cant change the status box from red to green.

In addition I connected to the Arduino terminal interface and it is apparent that the uploaded hex is working...AD9850 is recognized, CONNECT returns “CONNECTED-1” to “CONNECTED-5”.....what is strange when i use GETPINS it returns only zeros for all pins.

Any idea how to fix it?

Darek
Last edited by darec on Thu Jan 01, 1970 12:00 am, edited 0 times in total.
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Kees_01
Posts: 24
Joined: Fri Jun 15, 2018 7:05 am

Re: AD9850-ARDUINO Interconnect

Postby Kees_01 » Sun May 05, 2019 9:11 pm

Hi Steve,

In June 2018 I have succesfully experimented with the DDS-module AD9851/Arduino-UNO in combination with the RSP SAS-SPECTRUM Analyser software V 0.9. And with the use of your HEX-file “DDS_tracking_Uno.hex” of June 2018.
Recently I found your new RSP-SPECTRUM Analyser software V 1.0 and installed it.
After installation I found also a new map “Andrew Developments” with three Hex files in de submap RSP-Spectrum Analyser/ArduinoFirmware. I used X-loader.exe to upload file Trackgen_Uno.hex into the Arduino_UNO. Then I launched RSP-Spectrum Analyser.exe and pressed the Start button of the program. I pressed the Track gen button and then the right COM port (same as in June 2018). Red square. All buttons except the COM port selector in this Track gen section are not grayed out but can not be selected.
Opening the menu under Options tells there is no Tracking generator connected.
Then I closed the RSP-SPECTRUM Analyser program and launched the Arduino IDE.
With the communication window (115200 baud) I tried some of the Trackgen Commands like:
-”VERSION”. Trackgen answered “Trackgen V1.1 - Uno AD9850”
-“GETPINS” Trackgen answered “R:10 D:11 C:13 U:9 S:8”
-”GETDDSTYPE” Trackgen answered “DDSTYPE=1” (w.o. using SETDDSTYPE=1 before)

Apparently there is communication, but not from the spectrum analyser program.

When I read the thread of Jim WA8MPA (viewtopic.php?f=12&t=4336#p14769) then I think I have a similar issue.

Steve wrote: Try selecting the Arduino comm port a couple of times - does the red box turn to green ? My answer is No.

Jim is using, I think, the Trackgen_Mega2560.hex and I am using for my Arduino Uno the Trackgen_Uno.hex file, so I think the 2560 code is OK as well as the UNO code, but is the problem elsewhere in the comms link?

By the way, Steve, you wrote in your manual v1.0a that when using the trackgen commands with a terminal program to set the baudrate to 115,200. Does that mean that in the Spectrum Analyser program can only communicate with that baudrate (perhaps a stupid question of me)?

Best regards,
Kees

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Kees_01
Posts: 24
Joined: Fri Jun 15, 2018 7:05 am

Re: AD9850-ARDUINO Interconnect

Postby Kees_01 » Mon May 06, 2019 11:27 am

Hi Steve,

Following on my thread of yesterday I have also installed RSP-SpectrumAnalyser V1.0a on a laptop with Windows 10 (64 bits), the Arduino IDE and Xloader.
I uploaded Trackgen_Uno.hex from the Andrew Development submap successfully. Unfortunately also on the laptop there was no connection with Track gen reported from RSP-SpectrumAnalyser V1.0a. But with the serial monitor of Arduino I could communicate with the Trackgen "as usual" even when I played with the (advanced) settings of the COM port, such as 4 Databits, Parity Even or Odd, 2 stopbits as well as playing with FiFo Buffer Low setting of Rx- and Tx buffer. Trying these experiments under control of RSP-Spectrumanalyser then the square remains red.
When I use the Arduino IDE to send some commands as showed in your manual then commands like CONNECT, VERSION GETDDSTYPE etc. are working, but when I send for example SPOTF=3500000 then nothing happens at the Trackgen Output. With a scope ( 1 MOhm input) I measured a (bit distorted) sinewave of 15 MHz and about 0,7 Vtt on the Track gen output. That signal is there as soon as the Arduino is physically connected to the COM port. So it has nothing to do with a command that is sent to the Track gen.
I hope these experiments may help you to find the solution for the communication with the Trackgen from the RSP-SpectrumAnalyser program, although I have the impression, reading the first page of your manual under Known Problems, that you have already found what is causing this issue.

Best regards,
Kees

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KI7MWA
Posts: 1
Joined: Thu Jun 06, 2019 3:58 am

Re: AD9850-ARDUINO Interconnect

Postby KI7MWA » Sat Jun 08, 2019 12:39 pm

Just curious how y'all are powering the AD9850 board...off the Arduino 5V pin, off the breadboard rail...?
Last edited by KI7MWA on Thu Jan 01, 1970 12:00 am, edited 0 times in total.
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Mike2459
Posts: 320
Joined: Mon Jul 24, 2017 8:24 pm

Re: AD9850-ARDUINO Interconnect

Postby Mike2459 » Sat Jun 08, 2019 5:41 pm

I've done it both ways.

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