Consider supporting external ADC and subsystem box for Load Cell.

[harrisonCassar]

Motivation/Description

Currently, we are reading the load cell off of one of the 10 channels of the same ADC we use for our PTs in our DAQ box. Perhaps it'd be advantageous to instead read this single channel on a separate high-precision, high-frequency ADC, transmitting the voltage/processed reading through USB serial (similar abstraction that the Thermocouple box has).

This would provide a few advantages, including:

• Better modularity (separate subsystem in separate box).
• Better organization (different wiring/setup separate from PT box).
• Avoid slower polling rate/lower precision that the currently-used PiHAT ADC offers (quirk is that more channels it polls, slower data rate, and we care about high data-rate a LOT for the load cell!).

Work To-Be-Done

Work with the Ground Systems team to determine if this is desirable (Harrison thinks it is :) ). Would need extra components, including:

• High-precision ADC (with only maybe a few channels for a few Load Cells).
• Extra box.
• Teensy, or other microcontroller that is compatible with the ADC.

[philipdoucla]

Have we talked with Emily and the ground systems team about this yet? I think it would be desirable though.

[philipdoucla]

Talked with Ground Systems and Admin on this: full support.

Extra ADCs ordered (RPi Hat) and received. Teensy's in inventory. Box to be sourced/ordered.

Deferral of active work to Ground Systems. Future software work to bring up/support box is blocked by completion of physical ADC box.

~ TRC 1/23/23