1. The document discusses measuring energy usage of an Android Things project on a Raspberry Pi 3 using an Arduino Uno and INA219 sensor. It describes connecting the sensor to measure voltage, current and power usage, and reading the sensor data on the Arduino and into a Go program. 2. The project being measured consists of a Raspberry Pi 3 with screen, Ethernet, and USB power running an Android Things program with a Rainbow HAT add-on. Autonomy of the system is estimated based on measured power usage and battery capacity. 3. The conclusion emphasizes the importance of measurement for energy optimization and provides contact information for energy-related questions.

1. IotCeption
Energy Measurement of Android Things
on Raspberry PI 3 with Arduino Uno
[Olivier Philippot - @simplygreenit]

2. Who I am?
CTO Greenspector
@simplygreenit

3. Why you need to measure energy ?

5. In Classical Android
import android.os.BatteryManager;
import android.content.Context;
BatteryManager mBatteryManager =
(BatteryManager)Context.getSystemService(Context.BATTERY_SERVICE);
Long energy =
mBatteryManager.getLongProperty(BatteryManager.BATTERY_PROPERTY_ENERGY_COUNTER);
Slog.i(TAG, "Remaining energy = " + energy + "nWh");

6. Energy ...

7. The project schema ...
Shunt : INA219

8. I2C Interface

9. In real life

10. Android Things

11. The project under test
1 Raspberry Pi 3
1 Screen + 1 HDMI (Optional)
1 Ethernet
1 USB Cable for power (With some modifications)
1 micro SDCard
1 Rainbow Hat project

12. Why so much hate?
I2C can be read on Android Things ?

13. Arduino to measure
Arduino IDE + INA219 Library (C)
shuntvoltage = ina219.getShuntVoltage_mV();
busvoltage = ina219.getBusVoltage_V();
current_uA = ina219.getCurrent_mA()*1000;
loadvoltage = busvoltage + (shuntvoltage / 1000);
poweruWh = loadvoltage * current_uA;
Serial.println(poweruWh);
delay(100);

14. Serial reading on PC

15. Serial reading in golang
In Arduino program :
Serial.begin(115200);
Serial library in Go: github.com/goburrow/serial
flag.StringVar(&address, "a", "/dev/ttyACM0", "address")
flag.IntVar(&baudrate, "b", 115200, "baud rate")
flag.IntVar(&databits, "d", 8, "data bits")
flag.IntVar(&stopbits, "s", 2, "stop bits")
flag.StringVar(&parity, "p", "N", "parity (N/E/O)")

16. Making an computer oscillo
Highchart which read the data : http://localhost:8000/

17. Now we can play...

18. Results

19. Autonomy ?
1,4w in continuous / 5v = 280mAh
3000mAh battery ~ 11h of autonomy
2w in continuous / 5v = 400mAh
3000mAh battery ~ 7,5h of autonomy

20. Conclusion : Measure, Measure and
Measure
For Energy questions : @simplygreenit