M-Labs/thermostat
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channels: fix/optimize calibrate_dac_value()

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This commit is contained in:
Astro 2020-05-20 23:07:31 +02:00
parent cca0a77657
commit 35af543e33
3 changed files with 50 additions and 32 deletions
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1
src/channel.rs
View File

@ -1,3 +1,4 @@
use stm32f4xx_hal::hal::digital::v2::OutputPin;
use crate::{
ad5680,
channel_state::ChannelState,

79
src/channels.rs
View File

@ -1,4 +1,3 @@
use stm32f4xx_hal::hal::digital::v2::OutputPin;
use smoltcp::time::Instant;
use log::info;
use crate::{
@ -91,7 +90,6 @@ impl Channels {
_ => unreachable!(),
};
let value = (voltage.0 * dac_factor) as u32;
info!("set_dac {} {}", voltage, value);
match channel {
0 => {
self.channel0.dac.set(value).unwrap();
@ -127,6 +125,18 @@ impl Channels {
}
}
pub fn read_dac_feedback_until_stable(&mut self, channel: usize, tolerance: f64) -> Volts {
let mut prev = self.read_dac_feedback(channel);
loop {
let current = self.read_dac_feedback(channel);
use num_traits::float::Float;
if (current - prev).0.abs() < tolerance {
return current;
}
prev = current;
}
}
pub fn read_itec(&mut self, channel: usize) -> Volts {
match channel {
0 => {
@ -197,40 +207,47 @@ impl Channels {
/// for i_set
pub fn calibrate_dac_value(&mut self, channel: usize) {
let vref = self.read_vref(channel);
let mut best_value = 0;
let mut best_error = Volts(100.0);
for value in 1..=ad5680::MAX_VALUE {
match channel {
0 => {
self.channel0.dac.set(value).unwrap();
self.channel0.shdn.set_high().unwrap();
}
1 => {
self.channel1.dac.set(value).unwrap();
self.channel1.shdn.set_high().unwrap();
}
_ => unreachable!(),
}
let value = self.calibrate_dac_value_for_voltage(channel, vref);
info!("best dac value for {}: {}", vref, value);
let dac_feedback = self.read_dac_feedback(channel);
let error = vref - dac_feedback;
if error < Volts(0.0) {
info!("calibration done at {} > {}", dac_feedback, vref);
break;
} else if error < best_error {
best_value = value;
best_error = error;
}
}
self.set_dac(channel, Volts(0.0));
info!("best dac value for {}: {}, itec={}", vref, best_value, self.read_itec(channel));
let dac_factor = best_value as f64 / vref.0;
let dac_factor = value as f64 / vref.0;
match channel {
0 => self.channel0.dac_factor = dac_factor,
1 => self.channel1.dac_factor = dac_factor,
_ => unreachable!(),
}
}
fn calibrate_dac_value_for_voltage(&mut self, channel: usize, voltage: Volts) -> u32 {
let mut best_value = 0;
let mut best_error = Volts(100.0);
for step in (1..=12).rev() {
for value in (best_value..=ad5680::MAX_VALUE).step_by(2usize.pow(step)) {
match channel {
0 => {
self.channel0.dac.set(value).unwrap();
// self.channel0.shdn.set_high().unwrap();
}
1 => {
self.channel1.dac.set(value).unwrap();
// self.channel1.shdn.set_high().unwrap();
}
_ => unreachable!(),
}
let dac_feedback = self.read_dac_feedback_until_stable(channel, 0.001);
let error = voltage - dac_feedback;
if error < Volts(0.0) {
break;
} else if error < best_error {
best_value = value;
best_error = error;
}
}
}
self.set_dac(channel, Volts(0.0));
best_value
}
}

2
src/main.rs
View File

@ -56,7 +56,7 @@ const HSE: MegaHertz = MegaHertz(8);
#[cfg(not(feature = "semihosting"))]
const WATCHDOG_INTERVAL: u32 = 100;
#[cfg(feature = "semihosting")]
const WATCHDOG_INTERVAL: u32 = 10_000;
const WATCHDOG_INTERVAL: u32 = 30_000;
#[cfg(not(feature = "generate-hwaddr"))]
const NET_HWADDR: [u8; 6] = [0x02, 0x00, 0xDE, 0xAD, 0xBE, 0xEF];