Enbiggening the Project

Ultimately this project was spurred by the realization that— while one is tough— having two or more children can absolutely tank a healthy person's ability to exercise.  Research throughout the project has confirmed that strollers— even "jogging strollers"— are just not designed primarily for running. It's literally difficult to fit a side-by-side double jogger out the door, much less push it at any appreciable pace in even perfect (windless) weather.

No more.

I reproduced a very similar motor mount, changed some parameters and made a new drive pulley, and ported all the code to the ESP32. Because of time constraints I'm still using an RC BLDC motor controller, but the ESP32 has a MCPWM peripheral (!!!) that will soon be made use of.

Wireless Control

When I did the reddit thread a common repeating concern was for the safety of the cargo. While a disturbingly high number of people suggested requiring handcuffing oneself to the bars, it's obvious that in 2017 we don't need to do that: we have the technology for wireless handcuffs!

If the phone disconnects the motor is immediately stopped. Unfortunately it's not currently possible to consistently read the RSSI of a peripheral device on the ESP32, but we can vary the transmit power to affect the acceptable range. 

This also gives us a nice readable display and allows a more complicated interface for, e.g. pausing and resuming at intersections or running intervals (short periods of speeding up, e.g. run at your 5k race pace for 3 minutes, followed by 2 minutes slow recovery).