Part Number: MSP430FR2532
In a previous forum post (link), I was investigating the source of "drift" in MSP CapTIvate capacitance measurements. With the help of Dennis, we investigated various potential sources of this drift, and I wanted to share a few lessons-learned for the community.
Below are some of the techniques that could be used to help isolate the cause:
- Keep the device in a room with a stable temperature.
- Replace the electrode with a fixed-capacitor (surface-mount ideally) -- or cut the trace to the electrode entirely. This can help rule-out system vs. internal (e.g., MSP-related) drift.
- Utilize the CapTIvate example firmware and/or the CAPT-FR2633 EVM to help rule-out issues related to hardware or firmware.
- Connecting the device to a large local ground plane (or Earth ground) may help identify a potential "ground-shift" phenomena, which could impact the measurement for a floating system (see this post).
Hope this helps!
-Kenton
