Running SmartMesh on the MAX32655 with MicroPython

Industrial low-power wireless networks exhibit unique requirements in terms of reliability, battery lifetime and security. Time Synchronized Channel Hopping is a networking technique created to address these needs, which was standardized by working group IETF 6TiSCH. Analog Devices’ SmartMesh product lines have been the best-in-class TSCH implementation, exhibiting over 99.999% wire-like end-to-end reliability, a decade of battery lifetime, and certified security. With over 100,000 networks deployed, SmartMesh plays a market-leading role. Today, SmartMesh runs on the LTC5800, and often requires customers to drive it from a second external micro-controller, which increases cost. This paper introduces a port of SmartMesh to the MAX32655, a dual-core microcontroller and radio System on Chip: the RISC-V core runs the communication stack, the ARM Cortex-M4 core is left available to the customer. We show how that ARM Cortex-M4 core can run a MicroPython interpreter for faster prototyping and time-to-market. A simple script, designed to transmit packets over a SmartMesh network using MicroPython, requires only an additional 6 kB of RAM. Furthermore, by compiling this script into byte code, the processing time can be reduced to a quarter of its original duration.