package main
import (
"bufio"
"errors"
"fmt"
"log"
"math/rand"
"os"
"strconv"
"strings"
)
func findSerial() (string, error) {
dir, err := os.Open("/sys/bus/w1/devices/")
if err != nil {
return "", err
}
defer dir.Close()
devices, err := dir.Readdirnames(0)
if err != nil {
return "", err
}
for _, d := range devices {
if !strings.Contains(d, "w1 bus master") {
return d, nil
}
}
return "", errors.New("no 1-wire devices. did you load the kernel modules?")
}
func (s *SousVide) InitTherm() error {
var err error
if *FakeTemp {
s.Temp = s.Target
return nil
}
if s.Gpio.Stub {
s.Gpio.ThermFd, err = os.OpenFile(
"test_temp.txt", os.O_RDONLY|os.O_SYNC, 0666)
if err != nil {
return err
}
} else {
serial, err := findSerial()
if err != nil {
return err
}
s.Gpio.ThermFd, err = os.OpenFile(
fmt.Sprintf("/sys/bus/w1/devices/%s/w1_slave", serial),
os.O_RDONLY|os.O_SYNC, 0666)
if err != nil {
return err
}
}
s.Gpio.ThermReader = bufio.NewReader(s.Gpio.ThermFd)
return nil
}
func (s *SousVide) MeasureTemp() error {
if *FakeTemp {
if s.Heating {
s.Temp += Celsius(rand.Float64())
} else {
s.Temp -= Celsius(rand.Float64())
}
if s.Temp < 0 {
s.Temp = 0
}
return nil
}
s.Gpio.ThermFd.Seek(0, 0)
line, err := s.Gpio.ThermReader.ReadString('\n')
if err != nil {
return err
}
line = strings.TrimSpace(line)
data := strings.Split(strings.Split(line, "=")[1], " ")
if len(data) != 2 {
return errors.New(
fmt.Sprintf("malformed line from 1-wire interface: %s", line))
}
if data[1] != "YES" {
// read the next line to flush the buffer. when we get a NO status
// there's still a line with the last temperature it read
s.Gpio.ThermReader.ReadString('\n')
return errors.New(fmt.Sprintf(
"thermocouple did not return 'YES' status, got %s", line))
}
line, err = s.Gpio.ThermReader.ReadString('\n')
if err != nil {
return err
}
line = strings.TrimSpace(line)
val := strings.Split(line, "=")[1]
floatVal, err := strconv.ParseFloat(val, 64)
if err != nil {
return err
}
s.Temp = Celsius(floatVal / 1000)
log.Printf("read temperature %f", s.Temp)
return nil
}