Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: w31ha0 on July 29, 2015, 10:49:26 PM

Title: Can I connect jumper leads to solder onto a simple dc motor?
Post by: w31ha0 on July 29, 2015, 10:49:26 PM
Hi,

I'm new to robotics and am wondering if I can solder a jumper lead onto a DC motor with the other end connected to the raspberry pi. The jumper lead I'm thinking of is this:

http://www.kiatronics.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/7/0/70658.jpg (http://www.kiatronics.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/7/0/70658.jpg)

The left side will be connected to the raspi GPIO and the right side will be soldered to the DC motor. I've tried doing that but it doesn't seem to work.

If this is not possible,what kind of wires should I use to connect the motor directly to the raspi GPIO outputs?

Thanks
Title: Re: Can I connect jumper leads to solder onto a simple dc motor?
Post by: Plague on July 29, 2015, 11:47:10 PM
The left side will be connected to the raspi GPIO and the right side will be soldered to the DC motor. I've tried doing that but it doesn't seem to work.

If this is not possible,what kind of wires should I use to connect the motor directly to the raspi GPIO outputs?

If I understand your question you want to solder the jumper wire to the DC motor but the solder won't work?
If that the case,  you can  strip the tip of the jumper wire,  removing the pin and exposing the wire inside.  That way the solder can attach to the wire and the motor. Your jumper wire won't be jumping any more  ;D
Title: Re: Can I connect jumper leads to solder onto a simple dc motor?
Post by: cyberjeff on July 30, 2015, 03:21:42 AM
STOP

It's not clear what you are doing.

A servo has 3 wires, a power wire, a ground wire, and a signal wire. The signal wire carries a minute amount of  current and is typically hooked up to a GPIO pin configured as PWM. The ground and power carry the full load which may be an amp or so.

The GPIO of a Pi has a 16 mA  (.016A) max rating,  that is sufficient for lighting LEDS (a few) and signal wires to servos. It will not directly power motors.

If you have a servo, the wire shown is fine for connecting to the signal connection of the servo.

A DC motor has 2 connections and will probably draw several hundred mA. Hooking up a DC motor directly is a recipe for baked Pi. Don't even consider that!
Title: Re: Can I connect jumper leads to solder onto a simple dc motor?
Post by: cyberjeff on July 30, 2015, 08:18:09 AM
Shields are usually used to connect motors. You may also see that as a motor controller. Google that.

If  this is all new to you, you may wish to start with an Arduino as there are many off the shelf plug in boards that require no soldering.

The point I wish to make is that neither the Pi or any of the microcontrollers like an Arduino has enough current to drive a motor directly. It will need an interface to protect it and to supply enough current.