Hi everyone
I'm working a bit of a newbie and working on a first project following the Arduino Starter Kit.
I have read up quite a bit on the forums (and the documentation) regarding powering multiple components with external power but would appreciate a sanity check on my numbers as it's quite likely I made a mistake.
The project itself involves an ultra-sound sensor mounted to a servo (the popular "Radar" project), with a bluetooth module, and two DC motors to drive the whole thing around.
Based on data sheets and empirical comments on this forum and elsewhere I have determine the following power needs:
| Item | V | I (mA) | Comment |
|---|---|---|---|
| SG90 Servo | 5 V | 270 | Stall current up to 650+ mA |
| LED + 2kO Resistor | 5 V | 4 | |
| Ultrasonic distance sensor | 5 V | 15 | |
| bluetooth module | 5 V | 40 | |
| Arduino board overhead | 5 V | 100 | |
| Dual DC motors (2x) | 3 V | 2400 | Stall current at 2100 mA each |
| TOTAL | 2829 |
Here's how I think I can power it:
- I think the servo, the ultrasonic distance sensor, the LED, the bluetooth module as well as the arduino board could be powered with 5V through the USB port (up to 500mA) or a USB powerbank. I believe unless the Servo stalls this is sufficient and I have tested it (except for the bluetooth module) successfully.
- The Dual DC motors need 3V and draw a lot higher current. I think I can power it with 2x AA battery in series, thus yielding the necessary 3V. This would be connected to the VIN of the DRV8835 Dual Motor Driver Shield (powered separately from the rest of the Arduino).
Any guidance & advise would be appreciated!