Saturday (16th)
Worked on the LKM, but after working a while decided to switch to pigpio instead of using an LKM because measuring pulse width requires two interrupt handlers, one for rising and one for falling edge, or requires checking the pin level within the interrupt handler, which apparently takes a uncertain amount of time. Using pigpio instead polls the GPIOs at a set frequency, while this still isn’t the most accurate, at least the error will be predictable and there is no need to mess with the kernel.
Sunday/Monday (17th/18th)
Worked further on the proximity sensors (ultrasound). Managed to get two working at the same time using my program interfacing with pigpio. Wrote the library to support six, which is the number we need. Am mildly concerned about the performance of the rest of the software running on the pi given the pigpio’s need for polling, but so far it seems like it is okay. Would consider the proximity sensors essentially ready for testing.
Tuesday/Wednesday (19th/20th)
Worked on the bluetooth connectivity between the Pi and the Arduino. Figured out how to configure the HC05 bluetooth module for the Arduino to use. Tested out the C libraries for the Pi’s Bluetooth connectivity.