Arduino Biped project

Projects General Guidance
1

Hi. I have this project that I want to do. It’s a biped robot, controlled by an Arduino uno and a sensor shield. After lots of research, here is the list of what I bought so far in terms of arduino, shield and servos. I also have a second question about if yes or not I can add an ultrasonic sensor to my robot. Note that I haven’t purchased any batteries or power source yet because I need you guy’s help.

  1. 1x Arduino « uno » board
  1. 1x Generic sensor shield (to control the 6 servos)
  1. 6x generic MG996R servo motors

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First question is about how to power the shield, arduino board, and 6 servos.

I want to use an external power source the power the 6 servo motors. The shield has the possibility to power the servo motors using an external power supply, just need to remove the jumper. But my question is: what should I use as an external power source for the servos? A rechargeable battery? 4 1.5v AA batteries? Or something else? I need guidance for that and also how to use it, what voltage and if I need an extra part to make it work. Remember that I’m using 6 MG996R servo motors. I know there was other posts about the same issue, but they were absolutely not clear.

Now how do I power the arduino?
Should I just use a 9v battery? Or should I again use rechargeable batteries or something else? Please guide me on that.
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Now, can I use an ultrasonic sensor (HC-SR04) with my robot? I know that there is only 6 PWM pins on the arduino uno, and because I use 6 servo motors all 6 pins are going to be used. Does an ultrasonic sensor requires at least 1 PWM pin or can use any Digital pins? If it’s possible, is it hard to code? Because i’m not that good with coding haha. The goal of adding an Ultrasonic sensor would be: When the biped sees a wall or obstacle, it moves backwards. So is adding an ultrasonic sensor too complicated if all 6 pins of the uno already used by the 6 servos? If it’s too complicated or impossible I’m just going to keep it simple and not add one haha

I know it’s a lot of questions but I really needs help so it’s really appreciated :slight_smile:

Thank you all in advance :slight_smile:

2

9V block battery won't do. Use 4xAA at minimum, better 2sLiPo / 2x 18650. The rest ... just build it and see for your self, otherwise you won't learn :slight_smile:

3

Thanks dude :slight_smile:

4

So, I’m going to be using 2 18650 batteries to power the uno. But what about the 6 servos? Does anyone know if the ultrasonic sensor needs PWM pins to work? Thank you all again :slight_smile:

5

Or maybe it is more safe to use 6 x AA batteries to power the arduino uno instead of 2x18650 batteries? I want to power the uno trough the DC jack :slight_smile:

6

antoine35:
I know that there is only 6 PWM pins on the arduino uno, and because I use 6 servo motors all 6 pins are going to be used.

What you think you know is wrong. Servos do not need PWM pins. They can use any of the digital pins.

As it happens an HC-SR04 doesn't need PWM pins either. So definitely no problem there.

Steve

7

Thank you for that information, I wasn’t aware of that. But I still don’t know what to use to power my servos? Thank you in advance :slight_smile:

8

Four "AA" or "C" cells.