Understanding kart performance - Part 2
Goal: increase performance, every tenth counts!
After deciding what live telemetry we wanted from the kart, we setup the Podium app and PodiumConnect to provide an easily readable set of gauges for review and coaching. Below we'll go through the steering, brake and accelerator sensors we added to the karts.
For development we're using two test karts both setup and wired almost identically.
Below is the AiM Accelerator Pedal Position Sensor. The design is solid and durable, these karts get a lot of use. The brake hardware provides a defined range of integer data as you accelerate, this can be precisely calibrated and shown as a gauge in Podium.
Below is the AiM Steering Position Potentiometer. The steering position sensor provides a defined range of integer data as you turn the wheel, this can be precisely calibrated and shown as a gauge in Podium.
Below, under the karts nassau plate you can see the ASL PodiumConnect box on the left the AiM 4 port hub on the right. So far we're using 3 of the 4 ports and as we add more sensors we'll add an extra hub. Notice the hub and Podium are connected to the nassau plate using rubber mounts to help with vibration.
PodiumConnect has a single power source and is wired directly to the karts battery. Initially we had the PodiumConnect wired directly into the AiM 4 Port hub as it's able to provide power, however (this is being verified) the power from the hub is at 5v and the PodiumConnect requires 12v. As such PodiumConnect is unable to run from the hub’s power source, a shame as this would be the ideal model as it would save on extra wiring of PodiumConnect to the kart’s battery.
The MyChron5 has two power sources, when connected to the karts battery the Mychron5 Rechargeable Lithium is being charged from the 12v source. Interestingly the data coming via the PodiumConnect shows the external MyChron5 battery source at 12volts and the internal battery at around 5v...
Below is the AiM Brake Position Sensor. The harder you brake the closer the magnet on the brake pedal moves closer to the sensor and reads a higher value, simple and effective. The accelerator and brake sensors are pretty tough and easy to setup and configure.
The wiring has been kept as simple as possible. These karts have a hard life and will be racing soon. So easy fixes and updates are crucial. All the positive cables have been been piggy backed onto a single female connector. When finished we simply remove the connector from the battery terminal and all power is removed. To date we are providing power to the Podium and the AiM MyChron5 from the battery.
Behind the AiM MyChron5 the two connected cables are for power and the 4 port expansion hub. The PodiumConnect box is plugged into a port on the hub.
Cables and wiring are run from the top/bottom of the nassau plate down the front and under the kart to the battery.
Tight top view of the hardware and wiring from the back of the nassau plate.
Running the live telemetry from the PodiumConnect using the new Podium app running on a 7 year old MacBook Pro with the latest version of OSX. Our test setup for the day was connected with a Netgear 4G router with a 34" Samsung super high contrast 3000:1 monitor. Trackside we ran an Apple iPad with the new Podium software (see above for the output) again over 4G.
While this day was focused on testing the new Podium app and AiM sensors we still managed to drop a further 0.25 seconds of our PB lap time using the data.
See also Understanding Kart Performance - Part 1