K9AQ wrote:I can communicate with the Trackgen software from both the SAS and from a terminal, but I get no output out of the DDS.
When using the analyser, can you confirm that the red panel is changing to green, and if it does, that you then click the Enable button ? - Clicking Enable should send the frequency in the Spot freq box to the Uno. The Enable button turns the DDS on or off by either sending the spot frequency, or when disabling the DDS, by sending SPOTF=0. I've got a Uno running here now, and have found that sometimes I have to select the Uno's comms port a couple of times before it responds and I get a green light. My Mega responds immediately. I''ll look into that.
K9AQ wrote:i rewired the jumpers from the AD7850 to the Uno and reloaded the Uno software, using Xloader.
This is what I get using the Arduino terminal:
R:10 D:11 C:13 U:9
That looks correct, and confirms that the firmware is running and responding to input.
K9AQ wrote:I then used the SPOTF=7000000 command, which should have generated a sine wave on sinewave pin2. All I see on the scope is very low voltage noise.
K9AQ wrote:I then tested the AD7859 using an Arduino DDS test sketch.
I'm at a loss to understand why the DDS is not setting a frequency when you talk to the Uno using a terminal app. I've just tried both the Mega and the Uno, and they both work, from a terminal app, or from the analyser. Out of interest, have you tried the other commands to set up a sweep ? Might be worth a try, if nothing else it will give us some more data to work with. When the Unu or Mega is first powered up, it should set the DDS to a frequency of 30Hz (that's correct, 30Hz, not a typo) without any input at all. Can you confirm if this is happening ?
All very strange, but I'm sure we'll get to the bottom of it one way or another.