References
https://discuss.ardupilot.org/t/3dr-power-module/37684
Application
3DR ubec step down
Lithium Polymer (LiPo) Batteries
Arduino analogue read.
Pre-requisites knowledge
Arduino IDE
C++
Github
Download the github using the link below and save it in your Arduino projects folder.
https://github.com/brisbaneroboticsclub/Read3DRUbec
3DR ubec Pinout
The voltage and current sensor measures the voltage and current in the MAIN power circuit. It does not measure the 5 volt circuits.
Add a 12V DC motor to the main power circuit so we have some data to measure.
Connect the Arduino and motor to the ubec
| ubec | Arduino | DC motor |
| GND | GND | |
| GND | ||
| Voltage Sensor | A0 | |
| Current Sensor | A1 | |
| 5V | ||
| 5V | ||
| Main VCC | Motor +ve | |
| Main GND | Motor GND |
On a DC motor, it doesn’t matter which terminal is GND or VCC, the motor will turn the opposite direction.
Run the Arduino code
Now open the Arduino code download from the github.
Connect the Arduino to your computer. Ensure you’re using the right COM port and board type and UPLOAD the code.
Notes:
The voltage and amp signal are received as a ratio of 5V. The Arduino reads the voltage and converts it to a number between 0 and 1023.
We need to rescale this value to represent our data.
We measured the voltage across the DC motor while it was working and recorded 7.3Volts. To rescale the data, we multiplied the analogue value by 50.
You may want to verify the voltage you are reading is the same as the voltage drop across your device on the main power circuit.
The amp draw was too low and we were unable to verify it’s data. We used the same calculation to measure the amps. If you have a better solution, please let us know.
Did it work for you?
If this didn’t work, please message us or raise an issue on our github.
