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// Copyright 2021-2023 Jacob Alexander
//
// Licensed under the Apache License, Version 2.0, <LICENSE-APACHE or
// http://apache.org/licenses/LICENSE-2.0> or the MIT license <LICENSE-MIT or
// http://opensource.org/licenses/MIT>, at your option. This file may not be
// copied, modified, or distributed except according to those terms.
// ----- Modules -----
#![no_std]
//mod test; // TODO
pub mod lookup;
// ----- Crates -----
#[cfg(feature = "defmt")]
use defmt::*;
use heapless::Vec;
#[cfg(not(feature = "defmt"))]
use log::*;
// ----- Sense Data -----
/// Indicates mode of the sensor
/// Used to specify a different lookup table and data processing behaviour
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
pub enum SensorMode {
/// Run ADC in reduced precision mode to collect additional calibration data
/// Generally uses an alternate lookup table
Test(&'static lookup::Entry),
/// Low latency mode (usually the same as NormalMode)
LowLatency(&'static lookup::Entry),
/// Normal mode for ADC
Normal(&'static lookup::Entry),
}
impl SensorMode {
pub fn entry(&self) -> &lookup::Entry {
match self {
SensorMode::Test(entry) => entry,
SensorMode::LowLatency(entry) => entry,
SensorMode::Normal(entry) => entry,
}
}
}
/// Calibration status indicates if a sensor position is ready to send
/// analysis for a particular key.
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
pub enum CalibrationStatus {
/// Still trying to determine status (from power-on)
/// Raw value must settle within a range before the sensor is considered ready
/// This range is determined by the ADC mode that is currently set
/// (e.g. 600-800 for at least 5 seconds)
NotReady = 0,
/// ADC value at 0 (test mode only)
SensorMissing = 1,
/// Reading higher than ADC supports (invalid), or magnet is too strong (test mode only)
SensorBroken = 2,
/// Sensor value low (not enough data to quantify further)
SensorLow = 6,
/// Magnet detected, min calibrated, positive range
MagnetDetected = 3,
/// Magnet detected, wrong pole direction (test mode only)
MagnetWrongPole = 4,
/// Invalid index
InvalidIndex = 5,
}
impl CalibrationStatus {
/// Update calibration status
/// Returns true if the sensor is ready/calibrated
pub fn update_calibration(&mut self, reading: u16, mode: SensorMode) -> bool {
let entry = mode.entry();
// Make sure reading isn't too low
if reading < entry.min_ok_value {
// Don't try to determine the true state, we'll do that later
*self = CalibrationStatus::NotReady;
}
self.is_calibrated()
}
/// Easy check whether or not the sensor is ready
pub fn is_calibrated(&self) -> bool {
matches!(self, CalibrationStatus::MagnetDetected)
}
/// Detailed calibration status
/// Returns a more detailed calibration status (takes a few more steps and is not necessary
/// during normal operation)
pub fn detailed_calibration(&self, data: &SenseData) -> CalibrationStatus {
match self {
CalibrationStatus::MagnetDetected => *self,
_ => {
match data.mode {
// More detailed analysis due to additional ADC range
SensorMode::Test(entry) => {
if data.data.value == 0 {
CalibrationStatus::SensorMissing
} else if data.data.value > entry.max_ok_value {
CalibrationStatus::SensorBroken
} else if data.data.value < entry.min_ok_value {
CalibrationStatus::MagnetWrongPole
} else if data.data.value < entry.min_idle_value {
CalibrationStatus::SensorLow
} else {
CalibrationStatus::NotReady
}
}
// Simplified analysis due to optimized ADC range
SensorMode::LowLatency(entry) | SensorMode::Normal(entry) => {
if data.data.value < entry.min_idle_value {
CalibrationStatus::SensorLow
} else {
CalibrationStatus::NotReady
}
}
}
}
}
}
}
#[derive(Clone, Debug)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
pub enum SensorError {
CalibrationError(SenseData),
FailedToResize(usize),
InvalidSensor(usize),
}
/// Records momentary push button events
///
/// Cycles can be converted to time by multiplying by the scan period (Matrix::period())
#[derive(Copy, Clone, Debug, PartialEq, Eq)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
pub enum KeyState {
/// Passed activation point
On {
/// Cycles since the last state change
cycles_since_state_change: u32,
},
/// Passed deactivation point
Off {
/// Cycles since the last state change
cycles_since_state_change: u32,
},
}
/// Calculations:
/// d = linearized(adc sample) --> distance
/// v = (d - d_prev) / 1 --> velocity
/// a = (v - v_prev) / 2 --> acceleration
/// j = (a - a_prev) / 3 --> jerk
///
/// These calculations assume constant time delta of 1
#[derive(Clone, Debug)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
pub struct SenseAnalysis {
/// Threshold state
pub state: KeyState,
/// Distance value (lookup + min/max alignment)
pub distance: i16,
/// Velocity calculation (*)
pub velocity: i16,
/// Acceleration calculation (*)
pub acceleration: i16,
/// Jerk calculation (*)
pub jerk: i16,
}
impl SenseAnalysis {
/// Using the raw value do calculations
pub fn new(data: &SenseData) -> Self {
// Lookup distance
let entry = data.mode.entry();
let distance = entry.lookup(data.data.value, data.raw_offset);
// Update key state
let state = match data.analysis.state {
KeyState::On {
cycles_since_state_change,
} => {
if distance <= data.deactivation {
// Key is now off
KeyState::Off {
cycles_since_state_change: 0,
}
} else {
// Key is still on
KeyState::On {
cycles_since_state_change: cycles_since_state_change.saturating_add(1),
}
}
}
KeyState::Off {
cycles_since_state_change,
} => {
if distance >= data.activation {
// Key is now on
KeyState::On {
cycles_since_state_change: 0,
}
} else {
// Key is still off
KeyState::Off {
cycles_since_state_change: cycles_since_state_change.saturating_add(1),
}
}
}
};
// Calculate velocity/acceleration/jerk
let velocity = distance - data.analysis.distance; // / 1
let acceleration = (velocity - data.analysis.velocity) / 2;
// NOTE: To use jerk, the compile-time thresholds will need to be
// multiplied by 3 (to account for the missing / 3)
let jerk = acceleration - data.analysis.acceleration;
SenseAnalysis {
state,
distance,
velocity,
acceleration,
jerk,
}
}
/// Null entry
pub fn null() -> SenseAnalysis {
SenseAnalysis {
state: KeyState::Off {
cycles_since_state_change: u32::MAX,
},
distance: 0,
velocity: 0,
acceleration: 0,
jerk: 0,
}
}
}
/// Stores incoming raw samples
#[derive(Clone, Debug)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
pub struct RawData {
value: u16,
average: u16,
idle_count: u32,
}
impl RawData {
/// Create a RawData instance
pub fn new() -> Self {
Self {
value: 0,
average: 0,
idle_count: 0,
}
}
/// Updates the raw value with a new reading.
/// - Updates the running average
/// - Increments the idle if average is within specified range
/// - If idle count exceeds the specified threshold, the average is returned
/// This average is used to calibrate the minimum distance
pub fn update<const IDLE_LIMIT: usize>(&mut self, value: u16, mode: SensorMode) -> Option<u16> {
self.value = value;
// Update average
self.average = (self.average + value) / 2;
// Update idle count
let entry = mode.entry();
if self.average >= entry.min_idle_value && self.average <= entry.max_idle_value {
self.idle_count += 1;
} else {
self.idle_count = 0;
}
trace!(
"RawData::update: value: {}, average: {}, idle_count: {} ({}..{}:{})",
self.value,
self.average,
self.idle_count,
entry.min_idle_value,
entry.max_idle_value,
entry.sensor_zero,
);
// Return average if idle count exceeds threshold
if self.idle_count > IDLE_LIMIT as u32 {
Some(self.average)
} else {
None
}
}
/// Returns the current value
pub fn value(&self) -> u16 {
self.value
}
/// Returns the current average
pub fn average(&self) -> u16 {
self.average
}
/// Reset data, used when transitioning between calibration and normal modes
pub fn reset(&mut self) {
self.value = 0;
self.average = 0;
self.idle_count = 0;
}
}
impl Default for RawData {
fn default() -> Self {
Self::new()
}
}
/// Sense data is store per ADC source element (e.g. per key)
/// The analysis is stored in a queue, where old values expire out
/// min/max is used to handle offsets from the distance lookups
/// Higher order calculations assume a constant unit of time between measurements
/// Any division is left to compile-time comparisions as it's not necessary
/// to actually compute the final higher order values in order to make a decision.
/// This diagram can give a sense of how the incoming data is used.
/// The number represents the last ADC sample required to calculate the value.
///
/// ```text,ignore
///
/// 4 5 ... <- Jerk (e.g. m/2^3)
/// / | /|
/// 3 4 5 ... <- Acceleration (e.g. m/2^2)
/// / | /| /|
/// 2 3 4 5 ... <- Velocity (e.g. m/s)
/// / | /| /| /|
/// 1 2 3 4 5 ... <- Distance (e.g. m)
/// ----------------------
/// 1 2 3 4 5 ... <== ADC Averaged Sample
///
/// ```
///
/// Distance => Min/Max adjusted lookup
/// Velocity => (d_current - d_previous) / 1 (constant time)
/// There is 1 time unit between samples 1 and 2
/// Acceleration => (v_current - v_previous) / 2 (constant time)
/// There are 2 time units between samples 1 and 3
/// Jerk => (a_current - a_previous) / 3 (constant time)
/// There are 3 time units between samples 1 and 4
///
/// NOTE: Division is computed at compile time for jerk (/ 3)
///
/// Time is simplified to 1 unit (normally sampling will be at a constant time-rate, so this should be somewhat accurate).
///
/// A variety of thresholds are used during calibration and normal operating modes.
/// These values are generics as there's no reason to store each of the thresholds at runtime for
/// each sensor (wastes precious sram per sensor).
#[derive(Clone, Debug)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
pub struct SenseData {
/// Computed lookup for the raw ADC data
analysis: SenseAnalysis,
/// Calibration status of the sensor
cal: CalibrationStatus,
/// Raw data tracking of the sensor
data: RawData,
/// Temperature/humidity compensation for the ADC->distance lookup
raw_offset: i16,
/// Processing mode + lookup table for ADC
mode: SensorMode,
/// Activation point (distance, push direction)
/// TODO - The logic doesn't handle negative distance values yet where activation is less than
/// deactivation.
activation: i16,
/// Deactivation point (distance, release direction)
deactivation: i16,
}
impl SenseData {
/// Create a new SenseData instance
/// - mode: Sensor mode
/// - activation: Activation point (distance, push direction)
/// - deactivation: Deactivation point (distance, release direction)
pub fn new(mode: SensorMode, activation: i16, deactivation: i16) -> SenseData {
SenseData {
analysis: SenseAnalysis::null(),
cal: CalibrationStatus::NotReady,
data: RawData::new(),
raw_offset: 0, // Starts in NotReady mode, so this value is ignored
mode,
activation,
deactivation,
}
}
/// Add new sensor reading
/// Only returns a value once the sensor has been properly calibrated and is within
/// the expected range.
pub fn add<const IDLE_LIMIT: usize>(&mut self, reading: u16) -> Option<&SenseData> {
// Update raw data
if let Some(average) = self.data.update::<IDLE_LIMIT>(reading, self.mode) {
// New minimum value detected
// Due to temperature and humidity, the sensor may drift
//
// Calculate the offset from the pre-computed lookup table
let entry = self.mode.entry();
self.raw_offset = average as i16 - entry.sensor_zero as i16;
// When we have a new valid minimum value calibration is complete
self.cal = CalibrationStatus::MagnetDetected;
}
// If sensor is calibrated compute SenseAnalysis
// Make sure the incoming value doesn't break the calibration
if self.cal.update_calibration(reading, self.mode) {
// Update analysis
self.analysis = SenseAnalysis::new(self);
Some(self)
} else {
// If key state was active before, deactivate it and send an event
match self.analysis.state {
KeyState::On { .. } => {
self.analysis = SenseAnalysis::null();
Some(self)
}
_ => None,
}
}
}
/// Current sensor analysis
pub fn analysis(&self) -> Option<&SenseAnalysis> {
if self.cal.is_calibrated() {
Some(&self.analysis)
} else {
None
}
}
/// Current sensor calibration status
pub fn calibration(&self) -> CalibrationStatus {
self.cal
}
/// Current raw sensor data
pub fn data(&self) -> &RawData {
&self.data
}
/// Raw offset value
pub fn raw_offset(&self) -> i16 {
self.raw_offset
}
/// Current sensor mode
pub fn mode(&self) -> SensorMode {
self.mode
}
/// Current activation point
pub fn activation(&self) -> i16 {
self.activation
}
/// Current deactivation point
pub fn deactivation(&self) -> i16 {
self.deactivation
}
/// Update activation/deactivation points
pub fn update_activation(&mut self, activation: i16, deactivation: i16) {
self.activation = activation;
self.deactivation = deactivation;
}
/// Change sensor mode
pub fn update_mode(&mut self, mode: SensorMode) {
self.mode = mode;
}
}
// ----- Hall Effect Interface ------
pub struct Sensors<const S: usize> {
sensors: Vec<SenseData, S>,
}
impl<const S: usize> Sensors<S> {
/// Initializes full Sensor array
/// Only fails if static allocation fails (very unlikely)
/// - mode: Sensor mode
/// - activation: Activation point (distance, push direction)
/// - deactivation: Deactivation point (distance, release direction)
pub fn new(
mode: SensorMode,
activation: i16,
deactivation: i16,
) -> Result<Sensors<S>, SensorError> {
let mut sensors = Vec::new();
if sensors
.resize(S, SenseData::new(mode, activation, deactivation))
.is_err()
{
Err(SensorError::FailedToResize(S))
} else {
Ok(Sensors { sensors })
}
}
/// Add sense data for a specific sensor
pub fn add<const IDLE_LIMIT: usize>(
&mut self,
index: usize,
reading: u16,
) -> Result<Option<&SenseData>, SensorError> {
trace!("Index: {} Reading: {}", index, reading);
if index < self.sensors.len() {
Ok(self.sensors[index].add::<IDLE_LIMIT>(reading))
} else {
Err(SensorError::InvalidSensor(index))
}
}
pub fn get_data(&self, index: usize) -> Result<&SenseData, SensorError> {
if index < self.sensors.len() {
if self.sensors[index].cal == CalibrationStatus::NotReady {
Err(SensorError::CalibrationError(self.sensors[index].clone()))
} else {
Ok(&self.sensors[index])
}
} else {
Err(SensorError::InvalidSensor(index))
}
}
/// Max number of sensors
pub fn len(&self) -> usize {
S
}
pub fn is_empty(&self) -> bool {
S == 0
}
}
#[cfg(feature = "kll-core")]
mod converters {
#[cfg(feature = "defmt")]
use defmt::*;
#[cfg(not(feature = "defmt"))]
use log::*;
use crate::{CalibrationStatus, KeyState, SenseData, SensorMode};
use heapless::Vec;
use kll_core::layout::TriggerEventIterator;
impl SenseData {
/// Convert SenseData to a TriggerEvent
/// Criteria used to generate the event (an event may not be ready yet)
/// - Distance movement must be non-zero (velocity)
/// - Enough samples must be generated for each kind of event
/// This only matters when initializing the datastructures, steady-state always has
/// enough samples
/// * 1 sample for distance
/// * 2 samples for velocity
/// * 3 samples for acceleration
/// * 4 samples for jerk
///
/// In LowLatency mode only PressHoldReleaseOff events are generated using the per key
/// activation point configuration
pub fn trigger_events<const MAX_EVENTS: usize>(
&self,
index: usize,
ignore_off: bool,
) -> TriggerEventIterator<MAX_EVENTS> {
let mut events = Vec::new();
// Only create events if the sensor is calibrated
if self.cal == CalibrationStatus::MagnetDetected {
// Handle on/off events
match self.analysis.state {
KeyState::On {
cycles_since_state_change,
} => {
if cycles_since_state_change == 0 {
trace!("Reading: {} {:?}", index, self.analysis.state);
events
.push(kll_core::TriggerEvent::Switch {
state: kll_core::trigger::Phro::Press,
index: index as u16,
last_state: 0,
})
.unwrap();
} else {
events
.push(kll_core::TriggerEvent::Switch {
state: kll_core::trigger::Phro::Hold,
index: index as u16,
last_state: cycles_since_state_change,
})
.unwrap();
}
}
KeyState::Off {
cycles_since_state_change,
} => {
if cycles_since_state_change == 0 {
trace!("Reading: {} {:?}", index, self.analysis.state);
events
.push(kll_core::TriggerEvent::Switch {
state: kll_core::trigger::Phro::Release,
index: index as u16,
last_state: 0,
})
.unwrap();
// Ignore off events unless ignore_off is set
} else if !ignore_off {
events
.push(kll_core::TriggerEvent::Switch {
state: kll_core::trigger::Phro::Off,
index: index as u16,
last_state: cycles_since_state_change,
})
.unwrap();
}
}
}
// Handle analog events
match self.mode() {
SensorMode::Test(_) | SensorMode::Normal(_) => {
if self.analysis.velocity != 0 || ignore_off {
events
.extend_from_slice(&[
kll_core::TriggerEvent::AnalogDistance {
index: index as u16,
val: self.analysis.distance,
},
kll_core::TriggerEvent::AnalogVelocity {
index: index as u16,
val: self.analysis.velocity,
},
kll_core::TriggerEvent::AnalogAcceleration {
index: index as u16,
val: self.analysis.acceleration,
},
kll_core::TriggerEvent::AnalogJerk {
index: index as u16,
val: self.analysis.jerk,
},
])
.unwrap()
}
}
_ => {}
}
}
TriggerEventIterator::new(events)
}
}
}