The project started in December 2012 as a research project idea from Francois Taddei : the idea was to make a dog collar with motion sensors to study dogs (and cats ! ) activity. This is scientifically interesting because dogs live on average 20 years but they have the same age-related diseases as humans (e.g Alzheimer's disease). In addition most of dogs breeds have been sequenced and so the relation between the genotype of the dogs, their activity (from sensors) and the diseases they contract could help research on aging.

For dogs owners this tool could help the diagnosis of diseases and could also help to monitor "psychologic" health of the dog (for example a dog that suffer that suffer from loneliness when his owner is not home will adopt repetitive behavior such as running in circles).

First prototype

The first prototype was made using seeed studio film + motion frame + bluetooth frame as it was the perfect tool for fast prototyping as it had a arduino-compatible MCU (atmega328) and had already a SPI-flash for storing data , a 3-axis accelerometer , a LiPo battery charge IC and bluetooth 2.5.

We managed to get a first prototype working and we tested it on a dog of a veterinary school in Paris.

It appeared rapidly that we couldn't use this design for proper testing on many dogs because :

- the seeed film was too fragile without a frame underneath

- the prototype was too long (even for big dogs) because the seeedstudio film was designed for modularity and not for space saving. Each sensor occupy 1 frame (so it can be removed if needed) and so it is a "waste " of space.

So we chose for the second prototype to use the smallest arduino board possible and to designed a shield on top of it with the motion sensors.

Second prototype

For the second prototype we used the Sparkfun pro micro 3.3V / 8Mhz as it is one of the smallest arduino compatible board (3.3 cm x 1.7 cm), has many input / output and is running in 3.3V which is very convenient for sensors. In comparison with other small arduinos (e.g arduino pro micro) this board as the advantage to be based on the atmega32u4 and so it is natively usb compatible with any FTDI adapter.

I designed a shield to fit on top of the Sparkfun pro micro with a 6 DOF sensor (MPU6050), a SPI-flash memory (AT45db161) and a LiPo charge IC (max 1555). Eagle files of those design can be found in my github in the "opencollar-hardware" repository.

The bluetooth 2.5 module was on top of the shield.

To be continued !!!!