[CLOSED] AD9959 ebay board troubleshooting.

[edigi]

A photo of my board and chip + fixed source code cleaning (previous wrong attachment removed)...

[Bud]

I replied in my thread at the below link, the OP has closed this thread, I do not want to hijack it.

https://www.eevblog.com/forum/rf-microwave/all-you-need-to-know-about-the-chinese-ad9959-ebay-board/msg2210496/#msg2210496

[edigi]

One final note (for those who have trouble with it) about how to bring life to these boards before I stop hijacking this thread.
So if you carefully check my attached photo you may notice one of the leftmost pins has a yellow wire and it goes to GND.
Since the board has an external power plug it may immediately raise an alarm in your head, where does this wire go then?
Unfortunately it's not visible in the photo (not in the source code either) so I have to tell: a pin header abbreviated to PDC. So it's a power down control and in order not to power down the chip it has to be connected to GND (low value).

I don't remember anymore if I had trouble with this particular pin but I definitely remember that in case of the overwhelming majority of many boards I had some trouble with this kind of things. So with one notable exception (9954 that  had excellent documentation) I have not received any documentation whatsoever with these boards. Naturally one can match the pin headers based on the datasheet without much trouble but I've soon realized how easy is it to overlook one of these power down pins.
ADI chips have excellent power control features where different parts of the chip can be powered down (DDS, DAC, etc. I'm talking generally here not about just this particular board), many have related control bits, most have pins and many of those are connected to pin headers of the various board.

Since there is no schematic, one can wrongly assume (I did it initially in many cases) that probably they have some kind of pull-up/pull-down resistors so that by default they activate the chip (after all it's a kind of an evaluation board).
Totally wrong. Most (if not all; I can't remember anymore) are just left floating.
If you wouldn't like to waste countless hours when messing with this kind of boards this is definitely something not to forget and take special care...

[Kalvin]

A photo of my board and chip + fixed source code cleaning (previous wrong attachment removed)...

I have the same board but haven't had time to play with it yet. Thanks for the source code!  That will be most useful when trying out the board and determine whether its a lemon or not. 

Also, great thanks for Bud to start this thread. 

[cemelec]

I have one of those boards (from Aliexpress) and it works fine, tried various frequencies and PLL multipliers, all OK.

You probably know and have already done this, but initially I had problems until I grounded IO3 and PDC  then all went well.

I am using one of those "blue pill" STM32F103 boards + my own code

[rprr]

@edigi -- Thank you for the code. I'm going to try to implement it via python on my Raspberry Pi. 

Edit to add: I was able to get one of my two boards to work. The first key was the PDC control pin to ground. Thank you.

This was on a Raspberry Pi with Python. I used a Python program available on github (https://github.com/mgrau/ad9959) with a couple of minor mods.

1. Changed the program to use spi.writebytes to deliver the full payload including register address + data in one shot as mentioned in the datasheet.
2. I also specified the bus speed explicitly at 1MHz

I have just begun playing with it. I see lots of spurs. I don't have a proper SA, so using an RTL-SDR dongle with gqrx. Will read datasheet some more.

Many thanks again.