The peripheral chapters teach code that ships as template source, not as a prebuilt archive — which is why no libbento_peripherals.a appears anywhere and why this section is a tutorial set plus a quick reference rather than an nm-derived API dump. The two APIs the chapters lean on that are homed elsewhere on this site:

ipc_sensorhub_* — the cross-core hub the auto-push task writes into and the UI reads, including the four feed_* entry points CM55 uses to inject readings it took itself. Taught in J3 — The auto-push task and the sensor hub — homed with the IPC Core reference, Sensor hub.
cm55_controls_snapshot — the weak hook the CapSense IPC backend answers through. Homed with the IPC Core weak hooks, Weak hooks (implement, don't call).

Everything else is in the tree you are building:

sensor_i2c_*, bmi270_*, bmm350_*, dps368_*, sht40_*, potentiometer_*, capsense_*, sensor_auto_* — bento_libs/claw/common/mpy/, in both packages.
cm55_sensor_poll_*, cm55_pot_read_all, cm55_capsense_tick — proj_cm55/modules/cm55_sensor_poll/, in both packages. It is quoted by the CM55 Core and IPC Core reference pages (CM55 Core (libbento_cm55.a)) and by B2 — CM55 boot to first frame; this section does not restate it.
tesaiot_radar_*, radar_dsp_* — bento_libs/claw/kit-pse84-ai/libraries/tesaiot-radar/, in both packages. Taught in J6 — Radar.
The MicroPython modules — modsensors.c, modgpio.c and the QWA309 overlay. mtb-mpy only; the mtb-only package ships no mod*.c at all.