thermostat/src/channels.rs

600 lines
22 KiB
Rust

use core::cmp::max_by;
use heapless::{consts::U2, Vec};
use serde::{Serialize, Serializer};
use smoltcp::time::Instant;
use stm32f4xx_hal::hal;
use uom::si::{
f64::{ElectricCurrent, ElectricPotential, ElectricalResistance, Time},
electric_potential::{millivolt, volt},
electric_current::ampere,
electrical_resistance::ohm,
ratio::ratio,
thermodynamic_temperature::degree_celsius,
};
use crate::{
ad5680,
ad7172,
channel::{Channel, Channel0, Channel1},
channel_state::ChannelState,
command_parser::{CenterPoint, PwmPin},
command_handler::JsonBuffer,
pins,
steinhart_hart,
};
pub const CHANNELS: usize = 2;
pub const R_SENSE: f64 = 0.05;
// DAC chip outputs 0-5v, which is then passed through a resistor dividor to provide 0-3v range
const DAC_OUT_V_MAX: f64 = 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.channel_state(channel).vref = channels.read_vref(channel);
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 => {
let vref = self.read_vref(channel);
self.channel_state(channel).vref = vref;
vref
},
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 center_point = self.get_center(channel);
let r_sense = ElectricalResistance::new::<ohm>(R_SENSE);
let voltage = self.get_dac(channel);
let i_tec = (voltage - center_point) / (10.0 * r_sense);
i_tec
}
/// i_set DAC
fn set_dac(&mut self, channel: usize, voltage: ElectricPotential) -> ElectricPotential {
let value = ((voltage / ElectricPotential::new::<volt>(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_tec: ElectricCurrent) -> ElectricCurrent {
let vref_meas = match channel.into() {
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 = i_tec * 10.0 * r_sense + center_point;
let voltage = self.set_dac(channel, voltage);
let i_tec = (voltage - center_point) / (10.0 * r_sense);
i_tec
}
pub fn read_dac_feedback(&mut self, channel: usize) -> ElectricPotential {
match channel {
0 => {
let sample = self.pins_adc.convert(
&self.channel0.dac_feedback_pin,
stm32f4xx_hal::adc::config::SampleTime::Cycles_480
);
let mv = self.pins_adc.sample_to_millivolts(sample);
ElectricPotential::new::<millivolt>(mv as f64)
}
1 => {
let sample = self.pins_adc.convert(
&self.channel1.dac_feedback_pin,
stm32f4xx_hal::adc::config::SampleTime::Cycles_480
);
let mv = self.pins_adc.sample_to_millivolts(sample);
ElectricPotential::new::<millivolt>(mv as f64)
}
_ => unreachable!(),
}
}
pub fn read_dac_feedback_until_stable(&mut self, channel: usize, tolerance: ElectricPotential) -> ElectricPotential {
let mut prev = self.read_dac_feedback(channel);
loop {
let current = self.read_dac_feedback(channel);
if (current - prev).abs() < tolerance {
return current;
}
prev = current;
}
}
pub fn read_itec(&mut self, channel: usize) -> ElectricPotential {
match channel {
0 => {
let sample = self.pins_adc.convert(
&self.channel0.itec_pin,
stm32f4xx_hal::adc::config::SampleTime::Cycles_480
);
let mv = self.pins_adc.sample_to_millivolts(sample);
ElectricPotential::new::<millivolt>(mv as f64)
}
1 => {
let sample = self.pins_adc.convert(
&self.channel1.itec_pin,
stm32f4xx_hal::adc::config::SampleTime::Cycles_480
);
let mv = self.pins_adc.sample_to_millivolts(sample);
ElectricPotential::new::<millivolt>(mv as f64)
}
_ => unreachable!(),
}
}
/// should be 1.5V
pub fn read_vref(&mut self, channel: usize) -> ElectricPotential {
match channel {
0 => {
let sample = self.pins_adc.convert(
&self.channel0.vref_pin,
stm32f4xx_hal::adc::config::SampleTime::Cycles_480
);
let mv = self.pins_adc.sample_to_millivolts(sample);
ElectricPotential::new::<millivolt>(mv as f64)
}
1 => {
let sample = self.pins_adc.convert(
&self.channel1.vref_pin,
stm32f4xx_hal::adc::config::SampleTime::Cycles_480
);
let mv = self.pins_adc.sample_to_millivolts(sample);
ElectricPotential::new::<millivolt>(mv as f64)
}
_ => unreachable!(),
}
}
pub fn read_tec_u_meas(&mut self, channel: usize) -> ElectricPotential {
match channel {
0 => {
let sample = self.pins_adc.convert(
&self.channel0.tec_u_meas_pin,
stm32f4xx_hal::adc::config::SampleTime::Cycles_480
);
let mv = self.pins_adc.sample_to_millivolts(sample);
ElectricPotential::new::<millivolt>(mv as f64)
}
1 => {
let sample = self.pins_adc.convert(
&self.channel1.tec_u_meas_pin,
stm32f4xx_hal::adc::config::SampleTime::Cycles_480
);
let mv = self.pins_adc.sample_to_millivolts(sample);
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 = target_voltage + self.get_center(channel);
}
target_voltage = target_voltage / samples as f64;
let mut start_value = 1;
let mut best_error = ElectricPotential::new::<volt>(100.0);
for step in (0..18).rev() {
let mut prev_value = start_value;
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!(),
}
let dac_feedback = self.read_dac_feedback_until_stable(channel, ElectricPotential::new::<volt>(0.001));
let error = target_voltage - dac_feedback;
if error < ElectricPotential::new::<volt>(0.0) {
break;
} else if error < best_error {
best_error = error;
start_value = prev_value;
let vref = (value as f64 / ad5680::MAX_VALUE as f64) * ElectricPotential::new::<volt>(DAC_OUT_V_MAX);
match channel {
0 => self.channel0.vref_meas = vref,
1 => self.channel1.vref_meas = vref,
_ => unreachable!(),
}
}
prev_value = value;
}
}
// 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!(),
}
}
fn get_pwm(&self, channel: usize, pin: PwmPin) -> f64 {
fn get<P: hal::PwmPin<Duty=u16>>(pin: &P) -> f64 {
let duty = pin.get_duty();
let max = pin.get_max_duty();
duty as f64 / (max as f64)
}
match (channel, pin) {
(_, PwmPin::ISet) =>
panic!("i_set is no pwm pin"),
(0, PwmPin::MaxIPos) =>
get(&self.pwm.max_i_pos0),
(0, PwmPin::MaxINeg) =>
get(&self.pwm.max_i_neg0),
(0, PwmPin::MaxV) =>
get(&self.pwm.max_v0),
(1, PwmPin::MaxIPos) =>
get(&self.pwm.max_i_pos1),
(1, PwmPin::MaxINeg) =>
get(&self.pwm.max_i_neg1),
(1, PwmPin::MaxV) =>
get(&self.pwm.max_v1),
_ =>
unreachable!(),
}
}
pub fn get_max_v(&mut self, channel: usize) -> ElectricPotential {
let max = 4.0 * ElectricPotential::new::<volt>(3.3);
let duty = self.get_pwm(channel, PwmPin::MaxV);
duty * max
}
pub fn get_max_i_pos(&mut self, channel: usize) -> (ElectricCurrent, ElectricCurrent) {
let max = ElectricCurrent::new::<ampere>(3.0);
let duty = self.get_pwm(channel, PwmPin::MaxIPos);
(duty * max, max)
}
pub fn get_max_i_neg(&mut self, channel: usize) -> (ElectricCurrent, ElectricCurrent) {
let max = ElectricCurrent::new::<ampere>(3.0);
let duty = self.get_pwm(channel, PwmPin::MaxINeg);
(duty * max, max)
}
// Get current passing through TEC
pub fn get_tec_i(&mut self, channel: usize) -> ElectricCurrent {
(self.read_itec(channel) - self.read_vref(channel)) / ElectricalResistance::new::<ohm>(0.4)
}
// Get voltage across TEC
pub fn get_tec_v(&mut self, channel: usize) -> ElectricPotential {
(self.read_tec_u_meas(channel) - 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 duty = (max_v / max).get::<ratio>();
let duty = self.set_pwm(channel, PwmPin::MaxV, duty);
(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 duty = (max_i_pos / max).get::<ratio>();
let duty = self.set_pwm(channel, PwmPin::MaxIPos, duty);
(duty * max, 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 duty = (max_i_neg / max).get::<ratio>();
let duty = self.set_pwm(channel, PwmPin::MaxINeg, duty);
(duty * max, max)
}
fn report(&mut self, channel: usize) -> Report {
let vref = self.channel_state(channel).vref;
let i_set = self.get_i(channel);
let i_tec = self.read_itec(channel);
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,
vref,
dac_value,
dac_feedback: self.read_dac_feedback(channel),
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)
}
fn pwm_summary(&mut self, channel: usize) -> PwmSummary {
PwmSummary {
channel,
center: CenterPointJson(self.channel_state(channel).center.clone()),
i_set: (self.get_i(channel), ElectricCurrent::new::<ampere>(3.0)).into(),
max_v: (self.get_max_v(channel), ElectricPotential::new::<volt>(5.0)).into(),
max_i_pos: self.get_max_i_pos(channel).into(),
max_i_neg: self.get_max_i_neg(channel).into(),
}
}
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) -> f64 {
max_by(self.get_tec_i(0).abs().get::<ampere>(),
self.get_tec_i(1).abs().get::<ampere>(),
|a, b| a.partial_cmp(b).unwrap_or(core::cmp::Ordering::Equal))
}
}
#[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,
vref: ElectricPotential,
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),
}
}
}
#[derive(Serialize)]
pub struct PwmSummaryField<T: Serialize> {
value: T,
max: T,
}
impl<T: Serialize> From<(T, T)> for PwmSummaryField<T> {
fn from((value, max): (T, T)) -> Self {
PwmSummaryField { value, max }
}
}
#[derive(Serialize)]
pub struct PwmSummary {
channel: usize,
center: CenterPointJson,
i_set: PwmSummaryField<ElectricCurrent>,
max_v: PwmSummaryField<ElectricPotential>,
max_i_pos: PwmSummaryField<ElectricCurrent>,
max_i_neg: PwmSummaryField<ElectricCurrent>,
}
#[derive(Serialize)]
pub struct PostFilterSummary {
channel: usize,
rate: Option<f32>,
}
#[derive(Serialize)]
pub struct SteinhartHartSummary {
channel: usize,
params: steinhart_hart::Parameters,
}