jeol-t330a/succbone/succd/process.go

289 lines
6.5 KiB
Go

package main
import (
"context"
"errors"
"fmt"
"math"
"sync"
"time"
"k8s.io/klog"
)
// daemon is the main state of the succdaemon.
type daemon struct {
// adcPirani is the adc implementation returning the voltage of the Pfeiffer
// Pirani gauge.
adcPirani adc
failsafe bool
highPressure bool
gpioDiffusionPump gpio
gpioRoughingPump gpio
gpioBtnPumpDown gpio
gpioBtnVent gpio
gpioBelowRough gpio
gpioBelowHigh gpio
// mu guards state variables below.
mu sync.RWMutex
// adcPiraniVolts is a moving window of read ADC values, used to calculate a
// moving average.
adcPiraniVolts []float32
rpOn bool
dpOn bool
vent momentaryOutput
pumpdown momentaryOutput
aboveRough thresholdOutput
aboveHigh thresholdOutput
}
// momentaryOutput is an output that can be triggered for 500ms.
type momentaryOutput struct {
// output of the block.
output bool
// scheduledOff is when the block should be outputting false again.
scheduledOff time.Time
}
func (m *momentaryOutput) process() {
m.output = m.scheduledOff.After(time.Now())
}
func (m *momentaryOutput) trigger() {
m.scheduledOff = time.Now().Add(time.Millisecond * 500)
}
// thresholdOutput outputs true if a given value is above a setpoint/threshold.
// It contains debounce logic for processing noisy analog signals.
type thresholdOutput struct {
// output of the block.
output bool
// debounce is when the debouncer should be inactive again.
debounce time.Time
// threshold is the setpoint of the block.
threshold float64
}
func (t *thresholdOutput) process(value float64) {
if time.Now().Before(t.debounce) {
return
}
new := value > t.threshold
if new != t.output {
t.output = new
t.debounce = time.Now().Add(time.Second * 5)
}
}
// process runs the pain acquisition and control loop of succd.
func (d *daemon) process(ctx context.Context) {
ticker := time.NewTicker(time.Millisecond * 100)
defer ticker.Stop()
for {
select {
case <-ticker.C:
if err := d.processOnce(ctx); err != nil {
if errors.Is(err, ctx.Err()) {
return
} else {
klog.Errorf("Processing error: %v", err)
time.Sleep(time.Second * 10)
}
}
case <-ctx.Done():
return
}
}
}
// processOnce runs the main loop step of succd.
func (d *daemon) processOnce(_ context.Context) error {
v, err := d.adcPirani.Read()
if err != nil {
return fmt.Errorf("when reading ADC: %w", err)
}
d.mu.Lock()
defer d.mu.Unlock()
// Process pirani ringbuffer.
d.adcPiraniVolts = append(d.adcPiraniVolts, v)
trim := len(d.adcPiraniVolts) - 100
if trim > 0 {
d.adcPiraniVolts = d.adcPiraniVolts[trim:]
}
d.pumpdown.process()
d.vent.process()
_, mbar := d.piraniUnlocked()
d.aboveRough.process(float64(mbar))
d.aboveHigh.process(float64(mbar))
// max rate of 1.0 in 500 ms because ringbuffer holds 5 values
if d.piraniRateOfChange() > 2.0 {
if !d.failsafe {
d.failsafe = true
klog.Errorf("Pressure changed too fast; entering failsafe mode")
}
} else if mbar < 4e-6 {
// Unrealistic result, Pirani probe probably disconnected. Failsafe mode.
if !d.failsafe {
d.failsafe = true
klog.Errorf("Pirani probe seems disconnected; enabling failsafe mode")
}
} else {
if d.failsafe {
d.failsafe = false
klog.Infof("Values are plausible again; quitting failsafe mode")
}
}
if mbar >= 1e-1 {
if !d.highPressure {
d.highPressure = true
klog.Errorf("Pressure is too high; enabling diffusion pump lockout")
}
} else {
if d.highPressure {
d.highPressure = false
klog.Infof("Pressure is low enough for diffusion pump operation; quitting diffusion pump lockout")
}
}
if d.failsafe {
d.aboveRough.output = true
d.aboveHigh.output = true
d.dpOn = false
}
if d.highPressure {
d.dpOn = false
}
// Update relay outputs.
for _, rel := range []struct {
name string
gpio gpio
// activeHigh means the relay is active high, ie. a true source will
// mean that NO/COM get connected, and a false source means that NC/COM
// get connected.
activeHigh bool
source bool
}{
{"rp", d.gpioRoughingPump, false, d.rpOn},
{"dp", d.gpioDiffusionPump, true, d.dpOn},
{"pumpdown", d.gpioBtnPumpDown, true, d.pumpdown.output},
{"vent", d.gpioBtnVent, true, d.vent.output},
{"rough", d.gpioBelowRough, false, d.aboveRough.output},
{"high", d.gpioBelowHigh, false, d.aboveHigh.output},
} {
val := rel.source
if rel.activeHigh {
// Invert because the relays go through logical inversion (ie. a
// GPIO false is a relay trigger).
val = !val
}
if err := rel.gpio.set(val); err != nil {
return fmt.Errorf("when outputting %s: %w", rel.name, err)
}
}
return nil
}
func (d *daemon) piraniRateOfChange() float32 {
max := d.adcPiraniVolts[0]
min := d.adcPiraniVolts[0]
for _, val := range d.adcPiraniVolts {
if val < min {
min = val
}
if val > max {
max = val
}
}
max_bar = math.Pow(10.0, float64(max)-8.5);
max_mbar = float32(max_bar * 1000.0)
min_bar = math.Pow(10.0, float64(min)-8.5);
min_mbar = float32(min_bar * 1000.0)
(max_mbar - min_mbar)
}
// pirani returns the Pirani gauge voltage and pressure.
func (d *daemon) pirani() (volts float32, mbar float32) {
d.mu.RLock()
volts, mbar = d.piraniUnlocked()
d.mu.RUnlock()
return
}
func (d *daemon) piraniUnlocked() (volts float32, mbar float32) {
volts = 0.0
for _, v := range d.adcPiraniVolts {
volts += v
}
if len(d.adcPiraniVolts) != 0 {
volts /= float32(len(d.adcPiraniVolts))
}
// Per Pirani probe docs.
bar := math.Pow(10.0, float64(volts)-8.5)
mbar = float32(bar * 1000.0)
return
}
// rpSet enables/disables the roughing pump.
func (d *daemon) rpSet(state bool) {
d.mu.Lock()
defer d.mu.Unlock()
d.rpOn = state
}
// rpGet returns whether the roughing pump is enabled/disabled.
func (d *daemon) rpGet() bool {
d.mu.RLock()
defer d.mu.RUnlock()
return d.rpOn
}
// dpSet enables/disables the diffusion pump.
func (d *daemon) dpSet(state bool) {
d.mu.Lock()
defer d.mu.Unlock()
d.dpOn = state
}
// dpGet returns whether the diffusion pump is enabled/disabled.
func (d *daemon) dpGet() bool {
d.mu.RLock()
defer d.mu.RUnlock()
return d.dpOn
}
func (d *daemon) vacuumStatusGet() (rough, high bool) {
d.mu.RLock()
defer d.mu.RUnlock()
rough = !d.aboveRough.output
high = !d.aboveHigh.output
return
}
// pumpDownPressed toggles the pump down relay for 500ms.
func (d *daemon) pumpDownPress() {
d.mu.Lock()
defer d.mu.Unlock()
d.pumpdown.trigger()
}
// ventPress toggles the vent relay for 500ms.
func (d *daemon) ventPress() {
d.mu.Lock()
defer d.mu.Unlock()
d.vent.trigger()
}