GitHub

Fox Red Labs / Builds / Motor control, power and sensing

Read a knob or a voltage

A voltage read by the chip's converter and printed as a number.

Easy20 min

No recorded steps

Some pieces of it have run. There are no recorded steps for this project, so this page does not give any.

What exists:

  • LP-MSPM0G3507: Inside the chip only: supply read 3.29 V; no knob wired
  • LP-MSPM0L1306: Inside the chip only: supply read 3.31 V; no knob wired
  • LAUNCHXL-F2800137: TI's out-of-box demo prints an ADC reading; the pin was left floating, no knob wired

You would need the board, plus ELEGOO jumper wires.

Errors and fixes: LP-MSPM0G3507, LP-MSPM0L1306, LAUNCHXL-F2800137.

What to build next

Read a temperature sensorA temperature printed every second
Read six sensors on one plug-in boardHumidity, temperature, light and magnetic field printed once a second, with what each should read
How fast a chip reacts to a signalHow many cycles from a signal to its handler, and one motor-control step timed

Every build. The code for all of them is in the GitHub repository.

Evidence and limitsReads the chip's own supply (3.29 V); no knob wired. Ran on 3 boards. Results, sources, timing and limits.

Which boards ran it

  • Could work LP-MSPM0G3507: Inside the chip only: supply read 3.29 V; no knob wired
  • Could work LP-MSPM0L1306: Inside the chip only: supply read 3.31 V; no knob wired
  • Could work LAUNCHXL-F2800137: TI's out-of-box demo prints an ADC reading; the pin was left floating, no knob wired

Source files

  • README (LAUNCHXL-F2800137): setup and build steps

Demos with wiring

LP-MSPM0G3507 from above with one wire from J3 pin 30 to J1 pin 2

Pins are drawn on TI's board drawing; the source is in the repo next to the README. Open full size

Loop 1: the chip's voltage maker into its own voltmeter

You need

  • LP-MSPM0G3507 LaunchPad development kit: TI's 80 MHz Arm Cortex-M0+ board with 128 kB flash and 32 kB RAM, a built-in debugger, three buttons, two LEDs (one RGB) and light and temperature sensors.
  • ELEGOO jumper wires (120-piece pack): Male and female breadboard wires for connecting anything to anything.

Wiring

  1. Unplug USB
  2. One wire from J3 pin 30 (PA15, the DAC output) to J1 pin 2 (PA25, an ADC input). J1 pin 2 sits under the square 3V3 pad
  3. No jumpers move

What was measured

  • Gain error 0.34%, gain 0.99656, across 257 DAC steps, 16 ADC reads each, both against the 3.3 V supply
  • The ADC reads 0 to 13.5 codes low, averaging 7.2 codes or 0 to 11 mV; noise 1.56 codes, about 9.6 effective bits

Versions: MSPM0 SDK 2.11.00.07, TI Arm Clang 5.1.1; measured 2026-10-06.

Next: The same loop through the op-amp, and a second ADC channel.

How to repeat it: Jumper wires on the LP-MSPM0G3507: three loops to start. Errors and fixes: FAQ. Numbers from Loop tests: the G3507 measuring itself through two jumper wires.

Get the code and tell us how it wentThe clone command, the board folder with its AGENTS.md, reports from others, and the three report forms.

Get the code

Clone the repository and open the board's folder below. AGENTS.md is a plain text file of notes for AI coding assistants, and llms.txt at the root indexes the site for one.

git clone https://github.com/Fox-Red-Labs/fox-red-labs.git

Code is BSD-3-Clause, writing is CC BY 4.0; third-party folders keep their own licenses.

Built it? Tell us

Built this, or got stuck? Report it on GitHub with a few short answers. Your report shows here in your words, marked as yours. A failure that repeats on the bench gets its fix here.

Share a projectWhat you built or ported, what it runs on, a photo or a clip, and anything that did not work.Report a problemThe step, the exact error text, your tool versions. Once it repeats on the bench, the fix goes on the page.A prompt that workedWhat you typed and what came out.