Arden’s Status Report for 9/24

Due to the pivot to a new project idea, we have only had a few days to plan out the design of this new idea: WSN for early wildfire detection. Nevertheless, I have been researching medium-access protocols that we could use to minimize power in the WSN. The most promising one would be an asynchronous B-MAC protocol where the sender would have some notion of the designated receiver’s wakeup period, allowing it to send a much slower preamble. The preamble would ensure that the receiver and the transmitter are in the “awake” state before the actual sensor data is sent. However, this would mean that the sensor node cannot be fully turned off during the off state, as it would still need to receive the preamble. Fortunately, the STM32 has a low-power mode where UART is still enabled, so the board could still receive data from the LoRa transceiver in this lower power state. Conversely, we could implement a synchronous MAC protocol (much like TDMA) which would allow the STM32 to go into an even lower power state mode, but this requires regular beacons to account for RTC clock drift among the sensor nodes, which sounds much trickier to implement. I do believe we are behind because we chose an idea so late, but I believe we can catchup promptly by the end of next week with other teams. My goal is to get LoRa communication up and running between a pair of STM nodes, and finalize the MAC protocol design.