The weChook Racing and Driven teams have recently launched a joint project (Project eChook Nano) to develop a standalone system capable of logging important telemetry data from a Greenpower car. Both of our teams feel like we learn a lot from our current telemetry setups and that making this type of information more easily available for other team’s vehicles would be incredibly beneficial and would really help with the engineering and learning aspects of Greenpower racing.
Our aim in developing this hardware is create something simple and affordable that will allow those teams without electronics experience to collect live data from their car for analysis during races, and as something to study in between events. It will be based around an ArduinoNano, and be provided with the base software to perform standard logging functions, whilst giving the students the opportunity to implement their own code to customise the functionality as they see fit.
The hardware is designed to interface with an android app that Rowan has posted about here: http://www.greenpower.co.uk/forum/discussion/3335/data-logging-and-driver-information-display-android-app-offer
. The hardware on the car communicates with the app via bluetooth, and can provide instantaneous readouts to the driver, as well as logging the information for later analysis. The app will also use the phone’s sensors to supplement the information gathered from the hardware.
A further aim of the project is to provide the ability to live stream the information to web interface via the phone's 3g connection, allowing information to be viewed live from the pit wall. An exciting prospect to try to understand why a competitor car is accelerating past yours but consuming less amps….perhaps time to get the chain oil out during that next pit stop ;)
We’re designing with the following I/O (and some of our suggestions on what they can be used for):
- 2 x Voltage (12V, 24V)
- 2 x RPM (Motor, Wheel)
- 3 x Temperature (Different bits of the motor, battery)
- 1 x Current (Motor)
- Throttle Position
- Cycle View & Launch buttons (for use with the app)
- LED x 3 (visual status indication)
- Bluetooth Output (interface to the app)
- 2 x PWM output (Fan, Motor controller)
Our primary intention is for this to be a passive component, that can be added to a car with minimal disruption, and will not affect the actual running of the car - we don’t want to be responsible for taking someone out of a race! The pins are there however to receive a throttle position input, and output a PWM signal to a motor controller. Teams can pick and choose what sensors they feel are necessary for their learning, though we would suggest current consumption is the most interesting!
We’re are currently working hard to get the base system cost less than £40 to make this accessible to as many teams as possible. Sensors are not included in this figure but most are cheap components (bar the LEM current sensor which can be found for ~£18). Due to the open source nature of this project we aim to provide teams with all the information required to source and put together the hardware themselves, but initially we will provide a ‘build kit’ so we can get some hardware out there in the field and get keen teams testing it as soon as possible.
At the very least, we’ll be running the system on Electric TubeOfGlue (the weChook racing team’s development vehicle) for the season if no other teams are interested!
Please get in touch with us on here or on Twitter (@Ramjet_gpt) if this is something your team would be interested in having or even being involved with. We have captured our ideas here but it would be great to hear from others on what is most important to their team.
Best Regards from the team, @Ruds_JLR