Posts Tagged BusPirate

Hacking an Actions MP4 video player to show server statistics

The MP4 player is a small movie player that was used by real estate agents to advertise properties, typically by posting them to potential clients. I saw it on a friend’s desk at his house and asked about it, not being able to pass up an opportunity. Anything with electronics, screens, and batteries will always grab my attention. He had already removed it from its housing / box so I’ve got no idea what it originally looked like. Read the rest of this entry »

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Finding JTAG on a Canon ELPH100HS (IXUS115)

I’m currently working on a project involving a Canon ELPH100HS point and shoot camera and my first task was to tear it apart and find any low level hardware access that I could. I chose the IXUS115 mainly for it’s full 1080p video recording capabilities and there is a CHDK port for it, which, it was hoped, would make the reversing and hacking process easier. I was hoping to find a serial console port and JTAG access to the processor, to aid programming and debugging.
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Using the BusPirate with a SD card

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.

BusPirate and a SD card, together at last

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GPS Logger II – GPS Interfacing

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. Read the rest of this entry »

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