UPDATE: Roll your own GPS can now track twice as many satellites

diy-gps-module

[Andrew Holme] wrote in to tell us about some work he’s done to improve his scratch-built GPS receiver. He figured out a way to use the same hardware but double the number of satellites it can track to a total of eight. When we looked at the original hardware about a year ago it was limited to monitoring just four satellites. That’s the bare minimum for calculating position data. This will not only help increase the accuracy, but remove the problems that would have been cause if just one satellite was dropped because of an obstruction or other issue.

His solution is based entirely on using the FPGA in a different way. He had taken up almost all of the gates available in the Xilinx Spartan 3 chip. Now he’s implemented a CPU on the chip and is able take some of the work off of the hardware gate design by running code on it. He also found and squashed a bug in how the data was processed. He says his original work wasn’t taking into account the rotation of the earth when determining position. All of these improvements put his accuracy at +/- five meters even when he’s not tracking all eight satellites!

Building an Arduino Chiptunes project inside an FPGA

From time to time we find ourselves in the mood for some Chiptunes. You know, the music that accompanied all of the best 8-bit console games? These days there are a lot of projects that use the audio chips of yore to recreate the sounds, but you’re always faced with the issue of sourcing those parts. [Jack Gassett] took some inspiration from one of those projects, but solved the rare hardware dilemma by building his own Chiptunes MIDI device in an FPGA.

He saw one of our features on an Arduino controlled YM2149 programmable sound generator. He realized that you can already find FPGA libraries out there that mimic this sound generation hardware, and he’s already done extensive work with an Arduino soft processor. Why not combine the two?

He’s using a Papilio FPGA with a wing that includes a MIDI connector and audio-out jack. As you can hear in the clip after the break this sounds just like the real thing. And he’s got plans to roll as many different types of sound generating chips into the mix as possible. You know, one FPGA synth to rule them all.

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Arduino implemented on an FPGA

If you think that Arduinos are overkill in most projects we can do one better for you. [Jack Gassett] has a virtual Arduino running on a Field Programmable Gate Array. We checked in with [Jack] back in November to see his work with the AVR8 Soft Processor, an FPGA version of an AVR chip. Because the Arduino uses AVR it wasn’t too much of a leap to make this Arduino compatible. We’re lacking in imagination when hit comes to using this method productively, but we’re sure someone will find a way.

[Thanks Drone]