THE ART OF ENCODING A PCM TELEMETRY STREAM: ENCODING A TELEMETRY STREAM FOR LOW SIZE, WEIGHT AND POWER (SWAP) APPLICATIONS

Abstract

IRIG 106 Chapter 4 PCM compliant high-speed telemetry streams on resource-constrained microcontrollers are critical for defense applications such as medium caliber munitions and other SWaP- limited platforms. Low power microcontrollers often present limitations such as single buffer registers, that hinder continuous data transmission. Traditional protocols like Inter-Integrated Circuit (I2C) and Universal Asynchronous Receiver/Transmitter (UART) are unsuitable due to their inherent overhead. This paper explores techniques for generating compliant telemetry streams directly on low-power Texas Instruments (TI) MSPs. SPI is leveraged for efficient data transmission, achieving up to 10 Mbit/s and when SPI is unavailable, optimized bit-banging is used, achieving up to 625 kbit/s. This approach focuses on optimizing task scheduling and interrupt management to achieve reliable high-speed performance while maintaining power consumption under 10mW. The research provides valuable insights into overcoming the challenges of high-speed telemetry in resource-constrained defense systems.