SDRAM Controller

October 28th, 2014

Here is a very interesting Xilinx App note that includes full VHDL code for interfacing to a SDRAM chip. I’ve been meaning to see if this could be adapted as an example for the Papilio Pro, but never seem to find the time…



This document describes the VHDL design for interfacing CoolRunner™-II CPLDs with low power Mobile SDRAM memory devices. Mobile SDRAM is the ideal memory solution for wireless, handheld, and mobile computing applications, making this a perfect match with the Xilinx CoolRunner-II low power CPLD family.

Yet Another Synth project updated with drum from SD Card.

October 23rd, 2014

Papilio User Thomas just posted an updated video of his “Yet Another Synth” project with a new update, drums from the SD Card.

via gadgetfactory forum

I finally manage to add drum. Actually it read sample from the SD card. The current design is limited to one drum sound at the time. But I have in mind to enhance the system and be able to reproduce 4 drum sound in the same time in addition to the other sound ( up to 252 ).

Xilinx App Note: Writing Efficient Testbenches

October 21st, 2014



I’ve been looking through Xilinx App Notes recently and came across some great information to share on the blog. This app note gives lots of great background information that will help you in writing test benches to provide stimulus for your HDL code so you can perform simulation before you ever load a design to the Papilio.


Testbenches are the primary means of verifying HDL designs. This application note provides guidelines for laying out and constructing efficient testbenches. It also provides an algorithm to develop a self-checking testbench for any design.




UPDATE: DesignLab Libraries – FPGA circuits and sketches together!

October 16th, 2014

I’ve been hard at work on the DesignLab software and just wanted to share a video of how libraries will work in DesignLab. One of the major things we are doing with DesignLab is expanding on the Arduino IDE by coupling FPGA circuits to sketches. Every DesignLab project will be the combination of an FPGA circuit that you load to the Papilio DUO and a sketch that interacts with that circuit.

I was recently speaking with the FPGA wizard, Max Maxfield, about DesignLab and he pointed out that it is the Arduino libraries and the ability to share those libraries that make the Arduino great. He gave the advice that DesignLab should make creating and sharing FPGA libraries as easy and convenient as possible. Even better, provide a central location where people can share not only libraries but any projects they make with DesignLab. I took his words of wisdom to heart and have the first cut of that functionality ready to go.

Please take a look at this video to see how you can make your own libraries for DesignLab.

If you would like to kick the tires and check it out for yourself then please download the beta release of DesignLab. Please keep in mind this is a work in progress and still needs more refinement and it is only working in Windows at the moment.




October 14th, 2014

This is an interesting looking toolkit for the Arduino, and the Papilio, that lets you control widgets on your computer screen from your Arduino.

With that said, the WIDGEDUINO aims at making this process even faster and easier. Bristling with an array of meters, graphs and data entry widgets, the WIDGEDUINO is sure to be a hit with hackers, makers and engineers alike.

It’s based on the .NET framework and was designed with Visual Studio Windows Presentation Foundation. The user simply writes a sketch using the WIDGEDUINO library, and connects to a PC via serial or Ethernet to gain access to the assortment of awesome widgets.

Arduino has made a name for itself by being easy to use and has become an excellent tool for rapid prototyping of an idea. If one wakes up in the middle of the night in a eureka moment and hammers out a contraption – using an Arduino as the brains is about as fast and easy as it gets.


New Chip Alert: The ESP8266 WiFi Module (It’s $5)

October 9th, 2014

NewChipHere’s an exciting new Wifi module from China, at just $5 its hard not to put it in your project! The only downside is the existing datasheets and information is in Chinese, but a quick search on google is showing some promising documentation in English. Hopefully we will see these modules used more and more in projects.

Why is it cool? It’s a WiFi module with an SOC, making it somewhat similar to TI’s CC300 in conception (A.K.A. the thing that makes the Spark Core so appealing), in that a microcontroller on the module takes care of all the WiFi, TCP/IP stack, and the overhead found in an 802.11 network.

Hamster’s HDMI Input Project

October 7th, 2014

Take a look at this forum project that Hamster is working on – HDMI input! Watch as he generates video pulls it into a Papilio, then converts it to VGA output. Very cool. :)

I hit a brick wall on this for a couple of days – it locked correctly but no HSYNC or VSYNC was being detected by my TV. I’ve lent my ‘scope to a friend to fix his stereo so decided to play with smart LEDs instead.

However I had an minor epiphany tonight while getting the boy ready for bed – was looking for the wrong channel for the HSYNC and VSYNC signals. D’oh!

Here’s the test setup – Pipistrello generating HDMI (powered over the HDMI cable’s 5V line! :-/ ), over to my HDMI input wing, then into the Papilio Pro, and out via the 8 bit analogue VGA  output of the LogicStart.

Holy C@#p – it works!

Still a few little random pixel-level issues here and there. Looks like timing between clock domains and/or phase of the capture bit clock.

But on the other hand, the errors look consistent between each colour channel – somewhere around the middle of the LSB. Might be a TMDS decode issue.

I am stoked.

New Wings for the Papilio – two days only sale!

October 3rd, 2014


Good new today we got the MicroSD and the I/O Buffer wings back in stock after a long wait and we also have a couple brand new wings for the Papilio which are the RGB LED Panel and the VGA Camera wings and We are offering these awesome new products at a special price of $6.99 for the first two days only!

Now we have a great selection of Papilio wings and for those who don’t know much about this type of products: the wings plug into the Papilio board and provide peripheral functionality. The Papilio One can accept up to six Wings that can operate independently of each other. Wings usually provide ala carte functionality for rapid prototyping.