I order both Red Pitaya and Analog Discovery 2 , just to compare them and see if they can be used to do anything serious.
Red Pitaya looks very pre mature, but the web interface attracts me due to that i make a lot of remote control and measurements.
I can help you there.
As a useful bench instrumentThe AD fits the bill, the software is the best I've ever used on any USB instrument, plus it just plain works, I can't ever remember having any problem with the software or the hardware. It includes LA, digital pattern generator, scope and signal generator, and all can be run concurrently. The only thing I recommend is to get the BNC adapter, using the differential inputs alone is quite restrictive, and suing the BNCs affords a greater scope bandwidth.
The RP is little more a toy as far as being a useful bench instrument goes. Unlike the AD, it's not plug and play out of the box, you will need to make up an SD card and fiddle around figuring out the device's IP address, for some reason it doesn't register with my DNS or resolve as a broadcast on my LAN. Being able to access readings remotely may be a useful niche use for the RP. I am fairly certain that in its current state as a bench instrument even a beginner will be disappointed. However, as an SDR I can see this being a good use case, although it lacks front end preselection filters which is likely to be a problem if used directly on HF. Just using my finger as an antenna on the Ch1 attenuator handbag connector, I can pick up MW AM transmissions. I can also see its value as a low-IF or ZIF as part of an RF system. As an SDR was perhaps the only time I've felt that the RP excelled in any way.
As a tinkering deviceIf you are interested in hard core development, have reasonable Linux dev skills and are patient, then the RP might be what you want, but unlike the AD it's an unfinished article. The hardware and core software seem reasonably stable, and there is out of the box a set of reasonably useful FPGA IP configs that you can use without even having to touch any FPGA dev tools: that in itself is worthy of note. But beware, the instructions on building a functioning dev environment are woefully inaccurate and/or out of date. Having said that, my own use case is using this as part of a one off OEM design and as such there was little point in reinventing the wheel when hardware like this is already available.
For programming, the AD offers an API, but I'm not sure what you'd want to do more than the excellent software does already. I am not sure how well it can practically be used for continuous sampling, an essential requirement for SDR use, but the facility to do so is discussed briefly in the SDK. That might be a nice project for someone!
ConclusionBoth devices can be used under Windows, Linux (x86 & ARM) and OSX. The AD is USB high speed and bus powered, whereas the RP is Gig Ethernet or WiFi with the right adapter, and needs its own power supply.
In short, if you want a USB instrument with scope, signal generator, LA etc it's a no brainer, go for the AD1 or AD2. If you are a pointy head with lots of time on your hands and want to come up with the next big thing in SDR, the RP is probably the better choice.