The Gameduino Dazzler prototype is alive

First a quick recap. Gameduino 3X Dazzler will be a new addition to the Gameduino family of graphics/sound devices. Dazzler has no built-in screen. Instead, it outputs a standard 720p (1280x720 @ 60 Hz) video signal on a standard HDMI connector.

Last week the PCB had just arrived, and I set up the camera to take a few photos of it just as I was applying paste. This is the result; satisfying mounds of paste on each pad.


Here's a close-up of the FPGA's pads. (It's a Xilinx Spartan-6 LX9 in BGA-256.) These are 0.4 mm diameter on a 1.0 mm grid, so actually quite chunky. Stencil registration is quite satisfactory, even if I do say so myself: looks like it's within 100 microns.


Assembly is straightforward, using the cheap stereo microscope that I bought way back in 2013 for Gameduino 2. Because this design was mostly automatically generated, it is really regular. For example the capacitors are ordered by value, so C4-C27 are all 0.1 µF. Here everything is placed except the HDMI connector. There's no real rush -- the paste can sit in the open for an hour without apparent change. But in this case the hand-assembly is done in 10 minutes and it goes straight into the IR oven.


After another quick check for power shorts, it's time to hook it up. Not only did no smoke escape, but the FPGA identified itself over JTAG. It's alive!


Counterclockwise from top-right, : (1) A SPIDriver being used as a JTAG programmer. More on this hack in a later update. (2) A SPIDriver hooked up the regular SPI port, to talk to the BT815 GPU. (3) One of my many Sparkfun FTDI UARTs chatting to the onboard J1 CPU.

Here's the whole thing, running the same asteroids demo loop that I sent out a couple of weeks ago.



The FPGA is currently doing three jobs. It is

• connecting the external SPI port to the BT815 GPU
• taking the GPU's RGB signals as input and encoding them as HDMI 720p
• running a 50 MIPs 16-bit J1 CPU, with SwapForth

The CPU right now is useful for interactive debugging. It's really handy being able to pop up an interactive prompt to get and set the system's status.

Thanks for reading. As a reminder, the Excamera Store and Electric Dollar Store are both still shipping same-day via USPS first-class mail. Orders before 4pm Pacific ship same day.