'ebay' AD9954 DDS development board - anybody actually bought and used one? - Page 1
Forum section: electronics / general

author: SouthPark
author_rank: Contributor
timestamp: August 12, 2019, 12:35:53 am
content: First time for everything here. I took a punt on ordering one of these DDS AD9954 direct digital synthesis modules from ebay.One of these : "AD9954 DDS Signal Generator Module 400M Frequency RF Source Development Board"I figured that eventually I would encounter something that could be a hassle to get going, and this one is it. The seller supplied documentation that was nothing more than a circuit diagram, plus some 'C/C++' code in directories. So it looks like the seller might not be able to help much.It is probably a case of 'expected lesson' learned here (that'll teach me) ----- about not doing a quick check online (google etc) about whether anybody else has actually successfully used one of these things, or knows at least how to connect it up to something for programming it.I thought I'd try (push) my luck to see if anybody has used one of these, or has some leads on programming/working one of these. If the prospects aren't good with this device, then I'll be just fine with leaving this one go. It would be awesome though if this device is actually workable - somehow

author: mklengel
author_rank: Newbie
timestamp: August 12, 2019, 07:48:08 pm
content: Why not have a look here?https://www.analog.com/en/products/ad9954.html#product-overviewGesendet von iPhone mit Tapatalk Pro

author: MarkF
author_rank: Super Contributor
timestamp: August 12, 2019, 08:34:03 pm
content: It looks like it has a simple SPI interface.It should be pretty straight forward to figure out the commands from the datasheet and control it from any MCU.The size of the MCU will depend on how fancy you want to get.You could start with a basic Arduino to learn with.I used a PIC18F2550, a small OLED display and a rotary encoder to drive an AD9834 DDS.In my case, the display required more effort than the DDS.Connect up your favorite microcontroller and dig in.

author: Ian.M
author_rank: Super Contributor
timestamp: August 12, 2019, 11:16:26 pm
content: You may be under a misapprehension here. You cant program it then disconnect it from the programmer and use it standalone. It *MUST* be connected to a MCU that can initialise it in your desired operating mode and select an output frequency etc. every time its powered up. No initialisation == it sits there doing sweet F.A.It looks like a number of people have used it with an Arduino (but see below about logic levels), and there's a blog (with code) about using a similar board (same chip, different connector layout) with a Beaglebone Black to implement a signal generator with a web based UI to control it:https://www.element14.com/community/groups/test-and-measurement/blog/2013/12/28/building-a-frequency-synthesiserso it shouldn't be too hard to get going as long as you've got a 3.3V MCU board that you can program in C and some jumper wires to hook it up with.A quick look at its datasheet + the presence of a 3.3V regulator on its board indicates that its SPI interface uses 3.3V logic levels, and there is a note in the datasheet recommending *NOT* to overdrive its digital inputs, so if you want to avoid the need for level shifters, use a 3.3V MCU.If you'd like us to comment on the supplied schematic and sample C code, you'll need to give us a link to them.

author: SouthPark
author_rank: Contributor
timestamp: August 13, 2019, 04:29:51 am
content: Quote from: mklengel on August 12, 2019, 07:48:08 pmThanks! I did see that link (and others). I didn't know what or how to connect this particular ebay board up to something (like an arduino etc.). And the other barrier I had was ...... after connected up, not much idea about how to even begin to communicate with it haha. But it looks like there's some hope after people in this thread gave some comments and recommendations. I'm pretty sure I'm going to need that link you listed up eventually too. Thanks again!

author: SouthPark
author_rank: Contributor
timestamp: August 13, 2019, 04:37:56 am
content: MarkF and IanM ----- Thanks very much !!!!! I was definitely thinking that this AD9954 ebay development board was going to be forever unusable --- or had no hope of ever being used (assuming that the hardware actually is ok in it). What was worse is ----- I admit, I purchased 2 of these, under assumptions that there would be online sites showing at least some people using these. I won't make that mistake again!! And then, a AD9959 (different module, but similar kettle of fish) is on its way (in transit) right now, which wasn't good, until yesterday --- when I noticed a thread in eevblog about the AD9959 ebay board. But looks like the eevblog user put in a bunch of work into getting his to AD9959 ebay board to go ----- due to the board being designed incorrectly ---- or flawed. But at least there was a path to follow for that one. Looks like there's hope for my AD9954 boards too now. Thanks again for helping me with those details. Definitely appreciated!!! If I do get somewhere with it, I'll make sure to post up some info here about it. Thanks!!!!Quote from: Ian.M on August 12, 2019, 11:16:26 pmIan ..... I've merely attached the zipped documents that the ebay seller emailed through, just so that you and anyone can just take a peek. I had no idea what to do with them, so I didn't even try asking the ebay seller for more help ----- as I was predicting that they probably had no idea what to do as wellThe extra photo shows a 14 pin header (2 vertical rows of 7 pins):The left-hand-side set of pins (from top down) says: SDO,IOSY(I think), RST, PWR, 3V3, GND, GND.then the right-hand-side set of pins (top down) says: CS, SCK, SDIO, OSK, PS0, PS1, UPD.Then there's a 3-pin vertical header next-door that says (from top down): GND, SYNC-IN, SYNC-CLK.Trying to do some online searching right now for the pin that appears to be labeled something likeIOSY.

author: Ian.M
author_rank: Super Contributor
timestamp: August 13, 2019, 09:53:31 am
content: Look in theAD9954 datasheet, page 8. Its got all the pin names and functions for the chip. If you combine that with checking the schematic for your board, you can clear up any ambiguities.e.g. IOSY must be the IOSYNC input:Quote from: datasheeton pin 12 of the 14 pin header.

author: SouthPark
author_rank: Contributor
timestamp: August 13, 2019, 10:15:41 am
content: Thanks very much Ian for your help and going out of your way for showing me that link to that information. I'll use this information plus what you, mark and mkl showed earlier ... and work towards communicating and controlling this board. Will definitely report on any progress. Thanks again Ian. Greatly appreciated.

author: MarkF
author_rank: Super Contributor
timestamp: August 13, 2019, 03:28:04 pm
content: Did I also see a power selection header?I would think you would select the 3.3V mode.As @Ian.M mentioned, it looks like it has 1.8V or 3.3V logic levels depending on the power selection.See the "CMOS LOGIC INPUTS" parameters in the datasheet (page 6).At first, I thought it was 5V tolerant as indicated by Table 2 (page 7). Maybe someone else can verify this.Here is my first guess as to the other connector connections:BLUE letters are on the 14-pin headerRED letters are on the 3-pin header

author: Ian.M
author_rank: Super Contributor
timestamp: August 13, 2019, 04:22:13 pm
content: Datasheet fig. 3 footnote (page 7) saysQuote from: datasheetso no, it isn't officially 5V tolerant.I believe the O.P's EBAY board is hard wired for 3.3V logic.The jumper W1 is for clock input selection (either on-board 20MHz oscillator, or external via SMA connector CLK_IN (J2).