Papilio Duo - FPGA+Ardunio - Page 1
Forum section: electronics / general

author: IceKiller
author_rank: Newbie
timestamp: June 25, 2014, 09:06:26 pm
content: Hi,First of I backed this project, because I have been putting off working with FPGAs for 3-4 years.. They say they offer Arduino + FPGA which seems like a nice combination. + I used some of their other tools in the past.The only thing I worry about is the limitation in there FPGA design 'mode'. Someone else who I discussed this project said this:"Going from arduino libraries to full C is easy.. from FPGA drawing to VHDL not so much".So I am wondering what the FPGA experienced people here feel about this board and that it has an 'arduino'.https://www.kickstarter.com/projects/13588168/papilio-duo-drag-and-drop-fpga-circuit-lab-for-mak

author: bwat
author_rank: Frequent Contributor
timestamp: June 26, 2014, 07:21:12 am
content: I'm personally not seeing the advantages of this. I think there's better ways to learn about developing with FPGAs. Some of my thoughts:1) Digital design is taught to teenagers in technical colleges all over the world. It's not just for the academically gifted. Get a good book and work through it.2) Writing your design in Verilog (esp. structural Verilog) is a lot easier than putting 74 series logic chips together like we had to back in the day. Verilog really isn't hard.3) It takes about an hour or two to learn to enter a simple design and then configure a FPGA with that design. Seewww.altera.com/literature/tt/tt_my_first_fpga.pdf.4) FPGA boards are cheap. The DE0-Nano is pretty good for a starter. It's also got a shed-load (80) of I/O pins you could use to connect to an Arduino. It has an 8 channel ADC, 32MB SDRAM, and an accelerometer, so you really don't need the Arduino. I've attached a picture to show the two side by side.

author: miguelvp
author_rank: Super Contributor
timestamp: June 26, 2014, 07:47:39 am
content: You forgot to add the other 26 pins including the 8 analogs.I got a Nano, I did still back the DUO up. The papilio has the wishbone and libraries that make it easier than VHDL or Verilog for just using the FPGA as glue logic. Also I got it because I want a Spartan based FPGA, I have 3 Altera ones so far and the combination of an ATMega32 with the xilinx well it got my interest. Of course you can still do VHDL or Verilog.Have not worked with the Xilinx toolchain nor download it (I hear is pretty big so I might need to add a drive but I have to anyways since i'm always on the border of running out of space)Another thing is that the papilio has a big enough community, not crazy big but not so small that gets stale soon. Also it's mature as in most of the toolchain is already in place, the papilio has a lot of examples for the ZPUino with the DUO that soft core gets replaced with the ATMega32. One thing about Altera is that their IPs are closely tied to the NIOS II, I know they make FPGA/SoC chips and might eventually get one of those too.Anyways, the price is right, SRAM instead of SDRAM is a plus, and depends how they wire things up having the Arduino shields heavy lifting offloaded to the FPGA makes sense to me.To me the FPGA acts like glue to hardware, so it's kind of an electronic duct tape that allows you access to hardware not intended for your specific platform.So to me, the price is good, the community is growing and supportive, they proven themselves already with their previous papilios and I really want to expand my FPGA knowledge beyond Altera. Don't get me wrong, I love what Altera offers and how much documentation there is online, so it's time for me to expand my horizon.

author: IceKiller
author_rank: Newbie
timestamp: June 27, 2014, 07:38:14 am
content: @Bwat,thank you for your advise I may pick up that board as well.@MiguelVP,I do have several years.. *cough* decade *cough* programming experience.But for some reason the logic units that are used for FPGA always eluded my functional thinking..hoping that with the Papilio DUO and the community behind it I am able to break through the ice and get use to the methodology.

author: miguelvp
author_rank: Super Contributor
timestamp: June 27, 2014, 07:43:15 am
content: Quote from: IceKiller on June 27, 2014, 07:38:14 amI have more than 2 decades of professional programming experience, but I always tend to write concurrent code so in just 6 months playing with FPGAs on my spare time I find it quite natural. Then again I find Erlang pretty natural as a functional programming language.

author: bwat
author_rank: Frequent Contributor
timestamp: June 27, 2014, 07:56:04 am
content: Quote from: miguelvp on June 27, 2014, 07:43:15 amThis is very similar to my experience as well. A good book on digital design will do wonders for the OP. I used the bookMano, M. Morris, and Kime, Charles R.Logic and Computer Design Fundamentals. 2nd Edition. Prentice Hall, 2000.and you can see the notes I've taken along the way here:http://barrywatson.se/dd/. The book takes you from nothing to CPU design in around 600 pages (don't know what the newer editions are like).

author: Rerouter
author_rank: Super Contributor
timestamp: June 28, 2014, 09:43:59 am
content: Thank you bwat, I've been reading over the 3rd edition, and it is well written and exactly as you say, beginning from nothing,