# Accelerometer

    identifier: 0x1f140409
    extends: _sensor
    tags: C
    group: movement
    status: stable

A 3-axis accelerometer.

## Orientation

An accelerometer module should translate acceleration values as follows:

| Orientation           	| X value (g) 	| Y value (g) 	| Z value (g) 	|
|-----------------------	|-------------	|-------------	|-------------	|
| Module lying flat     	| 0           	| 0           	| -1          	|
| Module on left edge   	| -1          	| 0           	| 0           	|
| Module on bottom edge 	| 0           	| 1           	| 0           	|

We recommend an orientation marking on the PCB so that users can mount modules without having to experiment with the device. Left/bottom can be determined by assuming text on silk runs left-to-right.

## Registers

    ro forces @ reading {
        x: i12.20 g
        y: i12.20 g
        z: i12.20 g
    }

Indicates the current forces acting on accelerometer.

    ro forces_error?: u12.20 g @ reading_error

Error on the reading value.

    rw max_force?: u12.20 g @ reading_range

Configures the range forces detected.
The value will be "rounded up" to one of `max_forces_supported`.

    const max_forces_supported? @ supported_ranges {
    repeats:
        max_force: u12.20 g
    }

Lists values supported for writing `max_force`.

## Events

All events are debounced.

    event tilt_up @ 0x81
    event tilt_down @ 0x82
    event tilt_left @ 0x83
    event tilt_right @ 0x84

Emitted when accelerometer is tilted in the given direction.

    event face_up @ 0x85
    event face_down @ 0x86

Emitted when accelerometer is laying flat in the given direction.

    event freefall @ 0x87

Emitted when total force acting on accelerometer is much less than 1g.

    event shake @ 0x8b

Emitted when forces change violently a few times.

    event force_2g @ 0x8c
    event force_3g @ 0x88
    event force_6g @ 0x89
    event force_8g @ 0x8a

Emitted when force in any direction exceeds given threshold.