thermostat/src/channels.rs
2024-10-14 13:25:49 +08:00

654 lines
24 KiB
Rust

use crate::timer::sleep;
use crate::{
ad5680, ad7172,
channel::{Channel, Channel0, Channel1},
channel_state::ChannelState,
command_handler::JsonBuffer,
command_parser::{CenterPoint, Polarity, PwmPin},
pins::{self, Channel0VRef, Channel1VRef},
steinhart_hart,
};
use core::marker::PhantomData;
use heapless::{consts::U2, Vec};
use num_traits::Zero;
use serde::{Serialize, Serializer};
use smoltcp::time::Instant;
use stm32f4xx_hal::hal;
use uom::si::{
electric_current::ampere,
electric_potential::{millivolt, volt},
electrical_resistance::ohm,
f64::{ElectricCurrent, ElectricPotential, ElectricalResistance, Time},
ratio::ratio,
thermodynamic_temperature::degree_celsius,
};
pub enum PinsAdcReadTarget {
VRef,
DacVfb,
ITec,
VTec,
}
pub const CHANNELS: usize = 2;
pub const R_SENSE: f64 = 0.05;
// From design specs
pub const MAX_TEC_I: ElectricCurrent = ElectricCurrent {
dimension: PhantomData,
units: PhantomData,
value: 2.0,
};
pub const MAX_TEC_V: ElectricPotential = ElectricPotential {
dimension: PhantomData,
units: PhantomData,
value: 4.0,
};
const MAX_TEC_I_DUTY_TO_CURRENT_RATE: ElectricCurrent = ElectricCurrent {
dimension: PhantomData,
units: PhantomData,
value: 1.0 / (10.0 * R_SENSE / 3.3),
};
// DAC chip outputs 0-5v, which is then passed through a resistor dividor to provide 0-3v range
const DAC_OUT_V_MAX: ElectricPotential = ElectricPotential {
dimension: PhantomData,
units: PhantomData,
value: 3.0,
};
// TODO: -pub
pub struct Channels {
channel0: Channel<Channel0>,
channel1: Channel<Channel1>,
pub adc: ad7172::Adc<pins::AdcSpi, pins::AdcNss>,
/// stm32f4 integrated adc
pins_adc: pins::PinsAdc,
pub pwm: pins::PwmPins,
}
impl Channels {
pub fn new(pins: pins::Pins) -> Self {
let mut adc = ad7172::Adc::new(pins.adc_spi, pins.adc_nss).unwrap();
// Feature not used
adc.set_sync_enable(false).unwrap();
// Setup channels and start ADC
adc.setup_channel(0, ad7172::Input::Ain2, ad7172::Input::Ain3)
.unwrap();
let adc_calibration0 = adc.get_calibration(0).expect("adc_calibration0");
adc.setup_channel(1, ad7172::Input::Ain0, ad7172::Input::Ain1)
.unwrap();
let adc_calibration1 = adc.get_calibration(1).expect("adc_calibration1");
adc.start_continuous_conversion().unwrap();
let channel0 = Channel::new(pins.channel0, adc_calibration0);
let channel1 = Channel::new(pins.channel1, adc_calibration1);
let pins_adc = pins.pins_adc;
let pwm = pins.pwm;
let mut channels = Channels {
channel0,
channel1,
adc,
pins_adc,
pwm,
};
for channel in 0..CHANNELS {
channels.calibrate_dac_value(channel);
channels.set_i(channel, ElectricCurrent::new::<ampere>(0.0));
}
channels
}
pub fn channel_state<I: Into<usize>>(&mut self, channel: I) -> &mut ChannelState {
match channel.into() {
0 => &mut self.channel0.state,
1 => &mut self.channel1.state,
_ => unreachable!(),
}
}
/// ADC input + PID processing
pub fn poll_adc(&mut self, instant: Instant) -> Option<u8> {
self.adc.data_ready().unwrap().map(|channel| {
let data = self.adc.read_data().unwrap();
let state = self.channel_state(channel);
state.update(instant, data);
match state.update_pid() {
Some(pid_output) if state.pid_engaged => {
// Forward PID output to i_set DAC
self.set_i(channel.into(), ElectricCurrent::new::<ampere>(pid_output));
self.power_up(channel);
}
None if state.pid_engaged => {
self.power_down(channel);
}
_ => {}
}
channel
})
}
/// calculate the TEC i_set centerpoint
pub fn get_center(&mut self, channel: usize) -> ElectricPotential {
match self.channel_state(channel).center {
CenterPoint::VRef => self.adc_read(channel, PinsAdcReadTarget::VRef, 8),
CenterPoint::Override(center_point) => {
ElectricPotential::new::<volt>(center_point.into())
}
}
}
/// i_set DAC
fn get_dac(&mut self, channel: usize) -> ElectricPotential {
let voltage = self.channel_state(channel).dac_value;
voltage
}
pub fn get_i(&mut self, channel: usize) -> ElectricCurrent {
let i_set = self.channel_state(channel).i_set;
i_set
}
/// i_set DAC
fn set_dac(&mut self, channel: usize, voltage: ElectricPotential) -> ElectricPotential {
let value = ((voltage / DAC_OUT_V_MAX).get::<ratio>() * (ad5680::MAX_VALUE as f64)) as u32;
match channel {
0 => self.channel0.dac.set(value).unwrap(),
1 => self.channel1.dac.set(value).unwrap(),
_ => unreachable!(),
};
self.channel_state(channel).dac_value = voltage;
voltage
}
pub fn set_i(&mut self, channel: usize, i_set: ElectricCurrent) -> ElectricCurrent {
let i_set = i_set.min(MAX_TEC_I).max(-MAX_TEC_I);
self.channel_state(channel).i_set = i_set;
let negate = match self.channel_state(channel).polarity {
Polarity::Normal => 1.0,
Polarity::Reversed => -1.0,
};
let vref_meas = match channel {
0 => self.channel0.vref_meas,
1 => self.channel1.vref_meas,
_ => unreachable!(),
};
let center_point = vref_meas;
let r_sense = ElectricalResistance::new::<ohm>(R_SENSE);
let voltage = negate * i_set * 10.0 * r_sense + center_point;
let voltage = self.set_dac(channel, voltage);
negate * (voltage - center_point) / (10.0 * r_sense)
}
/// AN4073: ADC Reading Dispersion can be reduced through Averaging
pub fn adc_read(
&mut self,
channel: usize,
adc_read_target: PinsAdcReadTarget,
avg_pt: u16,
) -> ElectricPotential {
let mut sample: u32 = 0;
match channel {
0 => {
sample = match adc_read_target {
PinsAdcReadTarget::VRef => match &self.channel0.vref_pin {
Channel0VRef::Analog(vref_pin) => {
for _ in (0..avg_pt).rev() {
sample += self.pins_adc.convert(
vref_pin,
stm32f4xx_hal::adc::config::SampleTime::Cycles_480,
) as u32;
}
sample / avg_pt as u32
}
Channel0VRef::Disabled(_) => 2048_u32,
},
PinsAdcReadTarget::DacVfb => {
for _ in (0..avg_pt).rev() {
sample += self.pins_adc.convert(
&self.channel0.dac_feedback_pin,
stm32f4xx_hal::adc::config::SampleTime::Cycles_480,
) as u32;
}
sample / avg_pt as u32
}
PinsAdcReadTarget::ITec => {
for _ in (0..avg_pt).rev() {
sample += self.pins_adc.convert(
&self.channel0.itec_pin,
stm32f4xx_hal::adc::config::SampleTime::Cycles_480,
) as u32;
}
sample / avg_pt as u32
}
PinsAdcReadTarget::VTec => {
for _ in (0..avg_pt).rev() {
sample += self.pins_adc.convert(
&self.channel0.tec_u_meas_pin,
stm32f4xx_hal::adc::config::SampleTime::Cycles_480,
) as u32;
}
sample / avg_pt as u32
}
};
let mv = self.pins_adc.sample_to_millivolts(sample as u16);
ElectricPotential::new::<millivolt>(mv as f64)
}
1 => {
sample = match adc_read_target {
PinsAdcReadTarget::VRef => match &self.channel1.vref_pin {
Channel1VRef::Analog(vref_pin) => {
for _ in (0..avg_pt).rev() {
sample += self.pins_adc.convert(
vref_pin,
stm32f4xx_hal::adc::config::SampleTime::Cycles_480,
) as u32;
}
sample / avg_pt as u32
}
Channel1VRef::Disabled(_) => 2048_u32,
},
PinsAdcReadTarget::DacVfb => {
for _ in (0..avg_pt).rev() {
sample += self.pins_adc.convert(
&self.channel1.dac_feedback_pin,
stm32f4xx_hal::adc::config::SampleTime::Cycles_480,
) as u32;
}
sample / avg_pt as u32
}
PinsAdcReadTarget::ITec => {
for _ in (0..avg_pt).rev() {
sample += self.pins_adc.convert(
&self.channel1.itec_pin,
stm32f4xx_hal::adc::config::SampleTime::Cycles_480,
) as u32;
}
sample / avg_pt as u32
}
PinsAdcReadTarget::VTec => {
for _ in (0..avg_pt).rev() {
sample += self.pins_adc.convert(
&self.channel1.tec_u_meas_pin,
stm32f4xx_hal::adc::config::SampleTime::Cycles_480,
) as u32;
}
sample / avg_pt as u32
}
};
let mv = self.pins_adc.sample_to_millivolts(sample as u16);
ElectricPotential::new::<millivolt>(mv as f64)
}
_ => unreachable!(),
}
}
/// Calibrates the DAC output to match vref of the MAX driver to reduce zero-current offset of the MAX driver output.
///
/// The thermostat DAC applies a control voltage signal to the CTLI pin of MAX driver chip to control its output current.
/// The CTLI input signal is centered around VREF of the MAX chip. Applying VREF to CTLI sets the output current to 0.
///
/// This calibration routine measures the VREF voltage and the DAC output with the STM32 ADC, and uses a breadth-first
/// search to find the DAC setting that will produce a DAC output voltage closest to VREF. This DAC output voltage will
/// be stored and used in subsequent i_set routines to bias the current control signal to the measured VREF, reducing
/// the offset error of the current control signal.
///
/// The input offset of the STM32 ADC is eliminated by using the same ADC for the measurements, and by only using the
/// difference in VREF and DAC output for the calibration.
///
/// This routine should be called only once after boot, repeated reading of the vref signal and changing of the stored
/// VREF measurement can introduce significant noise at the current output, degrading the stabilily performance of the
/// thermostat.
pub fn calibrate_dac_value(&mut self, channel: usize) {
let samples = 50;
let mut target_voltage = ElectricPotential::new::<volt>(0.0);
for _ in 0..samples {
target_voltage += self.get_center(channel);
}
target_voltage /= samples as f64;
let mut start_value = 1;
let mut best_error = ElectricPotential::new::<volt>(100.0);
for step in (5..18).rev() {
for value in (start_value..=ad5680::MAX_VALUE).step_by(1 << step) {
match channel {
0 => {
self.channel0.dac.set(value).unwrap();
}
1 => {
self.channel1.dac.set(value).unwrap();
}
_ => unreachable!(),
}
sleep(10);
let dac_feedback = self.adc_read(channel, PinsAdcReadTarget::DacVfb, 64);
let error = target_voltage - dac_feedback;
if error < ElectricPotential::new::<volt>(0.0) {
break;
} else if error < best_error {
best_error = error;
start_value = value;
let vref = (value as f64 / ad5680::MAX_VALUE as f64) * DAC_OUT_V_MAX;
match channel {
0 => self.channel0.vref_meas = vref,
1 => self.channel1.vref_meas = vref,
_ => unreachable!(),
}
}
}
}
// Reset
self.set_dac(channel, ElectricPotential::new::<volt>(0.0));
}
// power up TEC
pub fn power_up<I: Into<usize>>(&mut self, channel: I) {
match channel.into() {
0 => self.channel0.power_up(),
1 => self.channel1.power_up(),
_ => unreachable!(),
}
}
// power down TEC
pub fn power_down<I: Into<usize>>(&mut self, channel: I) {
match channel.into() {
0 => self.channel0.power_down(),
1 => self.channel1.power_down(),
_ => unreachable!(),
}
}
pub fn get_max_v(&mut self, channel: usize) -> ElectricPotential {
ElectricPotential::new::<volt>(self.channel_state(channel).pwm_limits.max_v)
}
pub fn get_max_i_pos(&mut self, channel: usize) -> ElectricCurrent {
ElectricCurrent::new::<ampere>(self.channel_state(channel).pwm_limits.max_i_pos)
}
pub fn get_max_i_neg(&mut self, channel: usize) -> ElectricCurrent {
ElectricCurrent::new::<ampere>(self.channel_state(channel).pwm_limits.max_i_neg)
}
// Get current passing through TEC
pub fn get_tec_i(&mut self, channel: usize) -> ElectricCurrent {
let tec_i = (self.adc_read(channel, PinsAdcReadTarget::ITec, 16)
- self.adc_read(channel, PinsAdcReadTarget::VRef, 16))
/ ElectricalResistance::new::<ohm>(0.4);
match self.channel_state(channel).polarity {
Polarity::Normal => tec_i,
Polarity::Reversed => -tec_i,
}
}
// Get voltage across TEC
pub fn get_tec_v(&mut self, channel: usize) -> ElectricPotential {
(self.adc_read(channel, PinsAdcReadTarget::VTec, 16) - ElectricPotential::new::<volt>(1.5))
* 4.0
}
fn set_pwm(&mut self, channel: usize, pin: PwmPin, duty: f64) -> f64 {
fn set<P: hal::PwmPin<Duty = u16>>(pin: &mut P, duty: f64) -> f64 {
let max = pin.get_max_duty();
let value = ((duty * (max as f64)) as u16).min(max);
pin.set_duty(value);
value as f64 / (max as f64)
}
match (channel, pin) {
(_, PwmPin::ISet) => panic!("i_set is no pwm pin"),
(0, PwmPin::MaxIPos) => set(&mut self.pwm.max_i_pos0, duty),
(0, PwmPin::MaxINeg) => set(&mut self.pwm.max_i_neg0, duty),
(0, PwmPin::MaxV) => set(&mut self.pwm.max_v0, duty),
(1, PwmPin::MaxIPos) => set(&mut self.pwm.max_i_pos1, duty),
(1, PwmPin::MaxINeg) => set(&mut self.pwm.max_i_neg1, duty),
(1, PwmPin::MaxV) => set(&mut self.pwm.max_v1, duty),
_ => unreachable!(),
}
}
pub fn set_max_v(
&mut self,
channel: usize,
max_v: ElectricPotential,
) -> (ElectricPotential, ElectricPotential) {
let max = 4.0 * ElectricPotential::new::<volt>(3.3);
let max_v = max_v.min(MAX_TEC_V).max(ElectricPotential::zero());
let duty = (max_v / max).get::<ratio>();
let duty = self.set_pwm(channel, PwmPin::MaxV, duty);
self.channel_state(channel).pwm_limits.max_v = max_v.get::<volt>();
(duty * max, max)
}
pub fn set_max_i_pos(
&mut self,
channel: usize,
max_i_pos: ElectricCurrent,
) -> (ElectricCurrent, ElectricCurrent) {
let max = ElectricCurrent::new::<ampere>(3.0);
let max_i_pos = max_i_pos.min(MAX_TEC_I).max(ElectricCurrent::zero());
let duty = (max_i_pos / MAX_TEC_I_DUTY_TO_CURRENT_RATE).get::<ratio>();
let duty = match self.channel_state(channel).polarity {
Polarity::Normal => self.set_pwm(channel, PwmPin::MaxIPos, duty),
Polarity::Reversed => self.set_pwm(channel, PwmPin::MaxINeg, duty),
};
self.channel_state(channel).pwm_limits.max_i_pos = max_i_pos.get::<ampere>();
(duty * MAX_TEC_I_DUTY_TO_CURRENT_RATE, max)
}
pub fn set_max_i_neg(
&mut self,
channel: usize,
max_i_neg: ElectricCurrent,
) -> (ElectricCurrent, ElectricCurrent) {
let max = ElectricCurrent::new::<ampere>(3.0);
let max_i_neg = max_i_neg.min(MAX_TEC_I).max(ElectricCurrent::zero());
let duty = (max_i_neg / MAX_TEC_I_DUTY_TO_CURRENT_RATE).get::<ratio>();
let duty = match self.channel_state(channel).polarity {
Polarity::Normal => self.set_pwm(channel, PwmPin::MaxINeg, duty),
Polarity::Reversed => self.set_pwm(channel, PwmPin::MaxIPos, duty),
};
self.channel_state(channel).pwm_limits.max_i_neg = max_i_neg.get::<ampere>();
(duty * MAX_TEC_I_DUTY_TO_CURRENT_RATE, max)
}
pub fn set_polarity(&mut self, channel: usize, polarity: Polarity) {
if self.channel_state(channel).polarity != polarity {
let i_set = self.channel_state(channel).i_set;
let max_i_pos = self.get_max_i_pos(channel);
let max_i_neg = self.get_max_i_neg(channel);
self.channel_state(channel).polarity = polarity;
self.set_i(channel, i_set);
self.set_max_i_pos(channel, max_i_pos);
self.set_max_i_neg(channel, max_i_neg);
}
}
fn report(&mut self, channel: usize) -> Report {
let i_set = self.get_i(channel);
let i_tec = self.adc_read(channel, PinsAdcReadTarget::ITec, 16);
let tec_i = self.get_tec_i(channel);
let dac_value = self.get_dac(channel);
let state = self.channel_state(channel);
let pid_output = ElectricCurrent::new::<ampere>(state.pid.y1);
Report {
channel,
time: state.get_adc_time(),
interval: state.get_adc_interval(),
adc: state.get_adc(),
sens: state.get_sens(),
temperature: state
.get_temperature()
.map(|temperature| temperature.get::<degree_celsius>()),
pid_engaged: state.pid_engaged,
i_set,
dac_value,
dac_feedback: self.adc_read(channel, PinsAdcReadTarget::DacVfb, 1),
i_tec,
tec_i,
tec_u_meas: self.get_tec_v(channel),
pid_output,
}
}
pub fn reports_json(&mut self) -> Result<JsonBuffer, serde_json_core::ser::Error> {
let mut reports = Vec::<_, U2>::new();
for channel in 0..CHANNELS {
let _ = reports.push(self.report(channel));
}
serde_json_core::to_vec(&reports)
}
pub fn pid_summaries_json(&mut self) -> Result<JsonBuffer, serde_json_core::ser::Error> {
let mut summaries = Vec::<_, U2>::new();
for channel in 0..CHANNELS {
let _ = summaries.push(self.channel_state(channel).pid.summary(channel));
}
serde_json_core::to_vec(&summaries)
}
pub fn pid_engaged(&mut self) -> bool {
for channel in 0..CHANNELS {
if self.channel_state(channel).pid_engaged {
return true;
}
}
false
}
fn pwm_summary(&mut self, channel: usize) -> PwmSummary {
PwmSummary {
channel,
center: CenterPointJson(self.channel_state(channel).center.clone()),
i_set: self.get_i(channel),
max_v: self.get_max_v(channel),
max_i_pos: self.get_max_i_pos(channel),
max_i_neg: self.get_max_i_neg(channel),
polarity: PolarityJson(self.channel_state(channel).polarity.clone()),
}
}
pub fn pwm_summaries_json(&mut self) -> Result<JsonBuffer, serde_json_core::ser::Error> {
let mut summaries = Vec::<_, U2>::new();
for channel in 0..CHANNELS {
let _ = summaries.push(self.pwm_summary(channel));
}
serde_json_core::to_vec(&summaries)
}
fn postfilter_summary(&mut self, channel: usize) -> PostFilterSummary {
let rate = self
.adc
.get_postfilter(channel as u8)
.unwrap()
.and_then(|filter| filter.output_rate());
PostFilterSummary { channel, rate }
}
pub fn postfilter_summaries_json(&mut self) -> Result<JsonBuffer, serde_json_core::ser::Error> {
let mut summaries = Vec::<_, U2>::new();
for channel in 0..CHANNELS {
let _ = summaries.push(self.postfilter_summary(channel));
}
serde_json_core::to_vec(&summaries)
}
fn steinhart_hart_summary(&mut self, channel: usize) -> SteinhartHartSummary {
let params = self.channel_state(channel).sh.clone();
SteinhartHartSummary { channel, params }
}
pub fn steinhart_hart_summaries_json(
&mut self,
) -> Result<JsonBuffer, serde_json_core::ser::Error> {
let mut summaries = Vec::<_, U2>::new();
for channel in 0..CHANNELS {
let _ = summaries.push(self.steinhart_hart_summary(channel));
}
serde_json_core::to_vec(&summaries)
}
pub fn current_abs_max_tec_i(&mut self) -> ElectricCurrent {
(0..CHANNELS)
.map(|channel| self.get_tec_i(channel).abs())
.max_by(|a, b| a.partial_cmp(b).unwrap_or(core::cmp::Ordering::Equal))
.unwrap()
}
}
#[derive(Serialize)]
pub struct Report {
channel: usize,
time: Time,
interval: Time,
adc: Option<ElectricPotential>,
sens: Option<ElectricalResistance>,
temperature: Option<f64>,
pid_engaged: bool,
i_set: ElectricCurrent,
dac_value: ElectricPotential,
dac_feedback: ElectricPotential,
i_tec: ElectricPotential,
tec_i: ElectricCurrent,
tec_u_meas: ElectricPotential,
pid_output: ElectricCurrent,
}
pub struct CenterPointJson(CenterPoint);
// used in JSON encoding, not for config
impl Serialize for CenterPointJson {
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: Serializer,
{
match self.0 {
CenterPoint::VRef => serializer.serialize_str("vref"),
CenterPoint::Override(vref) => serializer.serialize_f32(vref),
}
}
}
pub struct PolarityJson(Polarity);
// used in JSON encoding, not for config
impl Serialize for PolarityJson {
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: Serializer,
{
serializer.serialize_str(match self.0 {
Polarity::Normal => "normal",
Polarity::Reversed => "reversed",
})
}
}
#[derive(Serialize)]
pub struct PwmSummary {
channel: usize,
center: CenterPointJson,
i_set: ElectricCurrent,
max_v: ElectricPotential,
max_i_pos: ElectricCurrent,
max_i_neg: ElectricCurrent,
polarity: PolarityJson,
}
#[derive(Serialize)]
pub struct PostFilterSummary {
channel: usize,
rate: Option<f32>,
}
#[derive(Serialize)]
pub struct SteinhartHartSummary {
channel: usize,
params: steinhart_hart::Parameters,
}