As part of a modding/tuning excercise I disassembled the radio. I used this opportunity to measure this radio’s latency properly, using test equipment. Tl;dr: the best-case latency observed was 13 ms, the worst-case was slightly over 43 ms. The typical was between 25-35 ms. Not great, not terrible.
The Helium Network is a LoRaWAN (~IoT) network provider — similar to TheThingsNetwork — which incentivize people by giving away its own cryptocurrency for creating network coverage. So far only a handful of us were trying to create LoRaWAN coverage in Hungary. Nowadays hordes of clueless fucks climb their roof to install their €500-1000 “miners” (most of them facing 5+ years of ROI). The results…
In this post I’ll show a relatively easy way to scale the MCU clock dynamically. There is a section in the STM32L4 MCU’s datasheet called “Supply current characteristics”, and it has an interesting table detailing power consumption for various payloads as µA/MHz. Such a table suggest to clock the MCU to a reasonably high frequency, and go to SLEEP mode as soon as CPU is not used. Unfortunately,…
STOP2 and STANDBY modes are great way to achieve uA and sub-uA consumption. When using an RTOS, the tasks must synchronize when to go to deepsleep, especially to STANDBY mode, which requires most hardware modules to be re-initialized. You must either create complex synchronization between tasks, and possibly create a “managing” task that puts the system into deepsleep, or you can use FreeRTOS…