So I'm waiting for the damn OLED display to be in stock in local distributors, which seems quite difficult to achieve over here.

In the mean-time I've played a bit with my Teensy 3.1 which was gathering dust at work. I was considering using NuttX RTOS as the base code for the device, however some basic functionality is not supported (mainly the RTC code). So, instead of over-complicating things, I will simply use the teensyduino IDE (Arduino IDE with Teensy support) until I really need something more complex (I'm abiding to KISS here, as an anti-procrastination measure).

My first goal is to be able to play with the OLED display in terms of interface design. After playing a bit with a simple smartwatch (which, co-incidentally has an OLED screen, but half size than the one I'm looking for) on my bike I've found some aspects I'm interested in:

1. The screen should stay on. Seems obvious, but my smart(dumb)watch requires a key-press and will stay on for up to 15 seconds
2. The screen should accommodate sufficient info all at once. My smartwatch (and other cheap bicycle computers, from what I've seen) requires key-presses to change screens (distance, time, speed, etc.). I would like to design a simple and informative screen which should accommodate things like speed as a gauge bar (I don't think reading a number makes sense here), distance as a small number (you don't need to read this while driving very fast), battery as a small icon, elapsed and current time, etc.

After I manage to find the OLED and this seems feasible, I will try to build a first version reading a standard magnetic sensor and having a LiPo battery + charger. Hopefully this should not take much more time.