Build a Quick, Easy (& Free) Ground Terminal!





Add all the microcontroller inputs and outputs your pretty lil' heart desires* by building a super simple ground terminal (block) out of common materials found at home!

Use this ground terminal to connect the ground leads of various components in your circuit. This is especially useful for Arduino or other microcontroller projects since there are a limited number of ground ("GND") pins.

Terminal blocks help simplify a circuit, provide a secure (& solderless) point of electrical connection, and reign in some of those pesky wires (which typically like to hang out all over the place and get tangled and stuck to everything..).

You can connect all the ground wires to one terminal or build multiple, electrically connected terminals for each component, like commercially available terminal blocks.

*Offer limited to the number of I/O pins on the microcontroller.

Step 1: Materials!

- One (1) 1" x 1" cardboard square

- One (1) metal paperclip

- One (1) bolt

Bolt size doesn't matter much as long as the washers and nuts are compatible.

- Two (2) washers

- Two (2) nuts

- One (1) wire

Step 2: Build It! Pt. 1

1. Poke a hole in the center of the cardboard square smaller than the size of the bolt.

2. Place one washer onto bolt, then add the paperclip, followed by the second washer. Push washers + paperclip to top of the bolt.

3. Twist one nut onto the bolt until it secures the washers around the paperclip.

Step 3: Build It! Pt. 2

1. Push bottom of bolt through cardboard hole.

2. Attach second nut on the bottom of the cardboard and tighten until it secures the bolt to the cardboard.

3. Add a ground wire to the paperclip (twist it on or use alligator clips), or otherwise electrically connect it to the bolt. Connect that ground wire to your circuit ground.

4. Add ground wires for each component with a ground connection.*

*You can also easily create a (low voltage/current) common wire with this!

Step 4: Connect It to Your Circuit!

And you're done!

This design was inspired while prototyping projects with a bunch of components that each require a GND connection. Typically, I'd end up with a giant mess of wires and alligator clips, half of the time accidentally shorting my circuit. This finally prompted me to design a super simple + quick ground terminal using materials easily available and plentiful at home.

Try different designs depending on your available materials and project needs-- most metals conduct electricity so there are tons of possibilities for a ground terminal! Share your designs in the comments below, or post a tutorial of your own! :D

Happy building!

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    3 Discussions


    1 year ago

    Using a single point for grounding, as this article advocates, prevents
    the problem known as "ground loop." If the circuit grounds are connected
    at different points, as to the chassis of an audio amplifier or the
    frame/unibody of a car, the tiny resistance between the points may
    allow a difference in potential (voltage) and a current will be noted
    between the points. For headlights and heater motors, the resistance
    is not a problem. The most common consequence is a "hum" noted in audio
    equipment. Whether this causes a problem in digital equipment is likely
    dependent on the frequency of the digital signals, potentially
    causing/allowing ringing or parasitic oscillation.

    Because the problem is small in terms of the signal, it may be difficult
    to find. People searching for the problems (there will never be only one)
    may suffer headaches, ulcers, hair loss, hair color change, tendency to
    throw things and scream at bystanders... Small children should not be
    allowed in the area.

    Years ago, I was working in a large performance building and talked with
    the head sound technician for a popular rock group. They would be having
    a show in a few hours. I asked and the sound (electrical) output of all
    the amplifiers on the stage and he calculated about 20,000 watts total.
    While we were talking, a crew member told him he had been shocked while
    assembling the aluminum stage.

    They had intentionally isolated the ground for the audio systems from
    the electrical ground for the building and somehow a serious ground loop
    had been created. He left me to go deal with it, saying he would have to
    find the piece of equipment whose signal ground was not connected to
    the master grounding point. I suppose he did, because the concert went
    on that evening. Fearing for my ears, I didn't attend.


    2 years ago

    Whew! For a second there, I thought you were suggesting using the bolt screw, to connect to a grounding pin of a power socket. (AC house Current ('.') ) (In certain parts of Europe, BAD Idea! since all 3 socket holes are round!). Another alternative, I usually use a Protoshield with the Arduino, and simply assign two wires from the two GND pins, to two adjacent breadboard pin sets[:::::], giving 8 more GND plugs. [::::]

    I just modified a pair of Protoshields, removing the outer pin rails, and replacing them with through-hold sockets, so now each pin is doubled. Mainly did this, because I wanted to use the Protoshield along with the keypad/LCD shield

    1 reply

    Reply 2 years ago

    Oh jeez yea using this with the house main voltage could end up very bad! It would probably be fine as the gnd connection, but shorts would be very dangerous and not worth the risk.

    Super cool to hear how you've solved the limited Arduino gnd pins in a different way, that sounds like a great approach! I might actually try that -- I've wanting to add an LCD screen to different projects but never seem to have enough pins leftover after adding sensors and such, lol.