Heart Rate, Power, Cadence, Speed, Weight, various training things are transfered by ANT+, currently the main collectors of the data all do some processing on it, and most bulky head units contain displays and other irrelevant things.
From inspiration from the Quarq Qollector and Metrigear, the idea is to take low cost components, combine with suitable firmware and collect all ANT+ messages sent on an SD Card.
These are the components currently being used:
These can be got from SparkFun in the US (ships internationally) or Robot Craft in Canada.
Total cost of the components is around $100 US.
The nRF2AP1 board needs to be connected to the Logomatic board, two power wires connecting the Gnd and 3.3V lines on the two boards. The TXO0 of the loggermatic connected to RX0 of the nRF24AP1 and the RXI0 of the loggermatic connected to the TX0 of the nRF2AP1.
The battery simply plugs in to the connector, and the SD card goes in the slot.
When assembled with the battery between the two boards as in the pictures below, the package ends up a little smaller than 7cm x 5cm x 2cm.
Suitable cases are still being investigated.
The firmware is currently under construction, and can be downloaded from the Git repository. To compile GnuARM or WinARM is needed, or there is normally a pre-compiled firmware available from the FW.SFE.
Once you have a copy of the firmware you plug in the board with a USB cable and copy the FW.SFE file to the root of the SD card. When you then remove the USB cable, the hardware will load your new firmware and you should see the status lights flash and it will start logging until you press the stop button.
Once you have collected some data, you can plug your device back into the USB and you will find a file ANT01.gce - or more if you have recorded more than one file.
The logfiles are stored in a binary format, containing the raw ANT+ messages and a checksum, and a timestamp. To make these useful, you need to decode them to get the raw data out. There's a Java program GoldenEmbedParser available to do this.
It is also possible to obtain a prebuild nightly build of the parser here: GoldenEmbedParser Nightly Build
To run the Parser simply type "java -jar GoldenEmbedParser.jar" with the antxx.gce filename you want to parse. It will output a .gc file that you can then import into GoldenCheetah
The project is its infancy and help and support is very much encouraged, there's a mailing list on google groups and it's also discussed on the GoldenCheetah IRC channel.