A Primer for Telemetry Interfacing in Accordance with NASA Standards Using Low Cost FPGAs

Abstract

Photon counting detector systems on sounding rocket payloads often require interfacing asynchronous outputs with a synchronously clocked telemetry stream. Though this can be handled with an on-board computer, there are several low cost alternatives including custom hardware, microcontrollers, and Field-Programmable Gate Arrays (FPGAs). This paper outlines how a telemetry interface for detectors on a sounding rocket with asynchronous parallel digital output can be implemented using low cost FPGAs and minimal custom hardware. Low power consumption and high speed FPGAs are available as Commercial Off-The-Shelf (COTS) products and can be used to develop the main component of the telemetry interface. Then, only a small amount of additional hardware is required for signal buffering and level translating. This paper also discusses how this system can be tested with a simulated telemetry chain in the small laboratory setting using FPGAs and COTS specialized data acquisition products.