feat: Analog sensor configuration (pin modes + packet format) #49

New issue

Open

opened 2026-08-29 20:53:57 +00:00 by time · 0 comments

time commented

2026-08-29 20:53:57 +00:00

Contributor

The firmware already reads the on-chip temperature sensor, the FVR channel (to derive VDD), and an external analog channel (RA4) and packs them into the packet. This generalizes that: the user picks which pins are analog and how the resulting ADC values are scaled and placed in the packet.

Open questions:

pin-mode configuration (which of the available analog pins are enabled, and their ADC channel)
how to represent the packet format declaratively (so the host tool's decoder generator can consume it)
scaling: raw ADC, voltage (using the FVR→VDD derivation already in the firmware), or a calibrated value (e.g. thermistor R→T via Steinhart-Hart / lookup)
whether to support the capacitive sensing (CPS) peripheral here or defer it

Configure which pins are analog inputs and how they map into the transmitted packet, for the first sensor class: resistive (variable-resistance temperature sensors, e.g. thermistors) and direct voltage measurements. The firmware already reads the on-chip temperature sensor, the FVR channel (to derive VDD), and an external analog channel (RA4) and packs them into the packet. This generalizes that: the user picks which pins are analog and how the resulting ADC values are scaled and placed in the packet. Open questions: - pin-mode configuration (which of the available analog pins are enabled, and their ADC channel) - how to represent the packet format declaratively (so the host tool's decoder generator can consume it) - scaling: raw ADC, voltage (using the FVR→VDD derivation already in the firmware), or a calibrated value (e.g. thermistor R→T via Steinhart-Hart / lookup) - whether to support the capacitive sensing (CPS) peripheral here or defer it