Nada Labs

The GPS Logger is currently able to access files and directories on a FAT16 filesystem, contained on a SD card. This post covers processing NMEA with a finite state machine and some of the problems encountered so far with the logger. (continue reading…)

As part of my GPS Logger project I needed to make sure that I could initialise and talk to a SD card over a SPI bus. The BusPirate is an excellent tool for testing  the physical and datalink layers. All parameters can be checked and adjusted on the fly without having to write any code. When the time comes to write code for the GPS logger, it will work first time as all the kinks and quirks were quickly worked out with the BusPirate.

This post covers SPI bus setup, card initialisation, reading and writing individual sectors.

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The system is now up and running. It is capable of communicating with the GPS receiver to get it into a known protocol (NMEA) and baud rate from an arbitrary starting configuration. I had to determine the pinout for the receiver as it was a USB GPS receiver. A check with the multimeter quickly identified the pinout of the four wires, TX was easy to spot as it was a constantly changing voltage whereas RX only changed when a command was sent. Once the prototyping is finished the USB receiver will be restored to its former glory. A few challenges were involved in figuring out the receivers startup configuration. It looks like at reset it outputs NMEA at 4800 baud but expects to receive NMEA configuration commands at 9600. This ‘interesting’ configuration was overcome by sending NMEA and SiRF configuration commands to the receiver at all supported baud rates. (continue reading…)

I like hiking, its a good excuse for getting outside, exploring the countryside, getting fit and having fun. While I can remember the places I’ve been and have photos as well, I would like to be able to record more information about the hike and be able to display the route taken in mapping applications. I have previously used a Laptop and USB GPS receiver in the car to record camping trips, however this is impractical when hiking as weight is an issue and the laptop battery only lasts a few hours. (continue reading…)

An overview of my honours project, covering the design and implementation of a research framework built in C++ to interface with USARSim. The major goal of this project was to be able to provide data to emperically validate control algortihms and justify design decisions. An overview of the libraries (Windows .dlls) and message flow between the various modules are presented. 

Various simulators exist for modelling robotic platforms, from the simple 2-dimensional to complex environmental and physics modelling. Most of these simulators require a large amount of support code to be written by the user before they are able to implement and test algorithms. This project aimed to develop a research platform for the testing and development of autonomous robot navigation and interaction while providing a means of experimentally validating algorithm efficiency and suitability. (continue reading…)

So you have a file that you know contains something good, if only you could read it. Your searching efforts for documentation proved fruitless, required a significant outlay or to sign a NDA. Looks like you are going to need to reverse engineer the file format so you can use it. Most applications tend to use custom file formats for various reasons. These files are usually containers where other files are kept or application data.  A hex editor (xvi32) and C compiler (VS2008) were used to discover the layout of the culprit file. (continue reading…)