go-embedded/embd
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embd
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fix bug with negative currents and add Power

This commit is contained in:
Cullen Jennings 2016-05-22 09:33:55 -06:00
parent 69655b6c03
commit e87156263c
2 changed files with 30 additions and 6 deletions
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9
samples/ina219.go
View File

@ -23,7 +23,7 @@ func main() {
bus := embd.NewI2CBus(1)
ina := ina219.New(bus, 0x40, 0.1)
ina := ina219.New(bus, 0x40, 0.001)
defer ina.Close()
for {
@ -42,7 +42,12 @@ func main() {
panic(err)
}
fmt.Printf("Shunt Voltage=%v Voltage=%v Current=%v\n", sv, v, c)
p, err := ina.Power()
if err != nil {
panic(err)
}
fmt.Printf("Shunt Voltage=%v Voltage=%v Current=%v Power=%v \n", sv, v, c, p)
time.Sleep(500 * time.Millisecond)
}

27
sensor/ina219/ina219.go
View File

@ -3,6 +3,7 @@
// interfcace.
// TODO - add options to config voltage range, sensitivity and averaging
// TODO - add documentation
package ina219
@ -54,7 +55,10 @@ func (d *INA219) setup() error {
d.mu.Lock()
defer d.mu.Unlock()
config := uint16(0x219F) // 12, bit no integration, 32v bus range , 40mV shunt range
//config := uint16(0x219F) // 12, bit no integration, 32v bus range , 40mV shunt range
//config := uint16(0x2777) // 12, bit 64x integration, 32v bus range , 40mV shunt range
config := uint16(0x2F77) // 12, bit 64x integration, 32v bus range , 80mV shunt range
err := d.Bus.WriteWordToReg(d.address, configReg, config)
if err != nil {
return err
@ -62,7 +66,7 @@ func (d *INA219) setup() error {
calib := uint16(0.5 + 40.96/d.shuntResitance)
err = d.Bus.WriteWordToReg(d.address, calibReg, calib) // .1 ohm sense resitor
err = d.Bus.WriteWordToReg(d.address, calibReg, calib)
if err != nil {
return err
}
@ -84,7 +88,7 @@ func (d *INA219) ShuntVoltage() (float64, error) {
return math.NaN(), err
}
voltage := float64(v) / 100000.0
voltage := float64( int16(v) ) / 100000.0
return voltage, nil
}
@ -114,7 +118,22 @@ func (d *INA219) Current() (float64, error) {
return math.NaN(), err
}
current := float64(v) / 1000.0
current := float64( int16(v) ) / 1000.0
return current, nil
}
func (d *INA219) Power() (float64, error) {
if err := d.setup(); err != nil {
return math.NaN(), err
}
v, err := d.Bus.ReadWordFromReg(d.address, powerReg)
if err != nil {
return math.NaN(), err
}
current := float64( int16(v) ) / 50.0
return current, nil
}