Graffiti is a good way to convey information to the public.
The earliest known graffiti dates back 30,000 years and uses traditional applications. -paint-to-wall technique.
Although our paintings are now canned rather than extracted from berries, the actual graffiti process has not really evolved from the original cave painting.
Although humans may not evolve new perceptions of cognitive art in thousands of years, our social and technological changes are faster than our brains can keep up with.
In a busy city, getting your message noticed means scrambling for attention.
Make your message stand out in posts-
Modern people, do this simple solar charging, permanent light art graffiti.
The first step is the basic darkness of the circuit. -
The wicked madness science detection circuit we used in the food alarm project.
The image from emslwe will use optical correlation resistors（LDR)
Replace the phototransistor above.
Since I learned how to make circuit boards, I have started every electronic project in this fragile bakery window.
Just put the circuit on the breadboard, Fritzing will automatically create a printed circuit board design in the next tab!
There are only a few components in our circuit.
Next, resistance（right)and LDR (left)
There are only two unpolarized components.
This means that they can be included in any direction of the circuit.
Next, the diode（left), LED (center)
Each circuit has a specific polarity and direction.
The negative end of the diode has a silver band.
The negative conductor of the LED is short, and there is a flat point on the plastic shell next to the negative conductor.
Next, the negative lead of the LED is on the left.
The transistor has three leads: emitter, base and collector.
The intermediate foot will be voltage supplied by the LDR sensor.
When the sensor is dark enough and the base voltage is high enough, the pins of the emitter and collector are connected, and the current can reach the LED through them.
Solar panels also have specific polarities.
Most of them are marked with positive and negative symbols.
Now that we understand the components and circuits of the circuit board, we can arrange the final layout of the circuit board Fritzing made for us.
Below is the final board image seen in the Fritzing program.
Because I couldn't add a white screen printing layer, I added copper text on the board to guide the assembly.
Fritzing will not automatically provide you with the most easily etched circuit boards at home.
I set the tracking width to the maximum to ensure a stable connection.
After clicking the Auto Route button at the bottom of the Fritzing window, adjust the tracking width and separate the tracking from each other as far as possible to avoid short circuit.
This is the last PCB image I used to etch the copper clad laminate. . .
I have two circuit spaces on board. . .
My first iteration had some drawbacks.
I mended them with component wires and some careful welding.
The current design has been determined.
I forgot to add 1K resistance to the circuit diagram!
Fortunately, the hole I drilled was large enough to install resistance leads.
Three AAA batteries keep the LED on at night.
When the morning comes, the LDR turns off the lights and lets the solar panels charge the batteries!
This solar panel has a rating of 4.
Five volts, that's perfect, because three AAA batteries add up to four. 5 volts.
Under a common halogen lamp, the brightness of the battery panel is 4. 14 volts!
If the battery runs out, charge it at 4:00 for a whole day.
Four volts of voltage will bring graffiti back online before nightfall.
Even with full coverage, the panel will pop up 1. 6 volts!
Step 2: A strong shell is important for a durable light graffiti.
Ideally, it should be able to withstand wind, rain and hail. -even floods.
I used this black plastic project box.
It has convenient hole mounting plate, battery and panel with screw.
I fixed the panel with solid wires.
Now I can bend it in any direction to face the sun!
If your circuit board is too big to accommodate the housing, you can cut it to a certain size.
The glass on the board does not inhale dust particles well, so I recommend not cutting with rotary tools.
When wearing breathing safety equipment, use plastic marking knife or steel saw.
I am satisfied with the final board of directors.
It's strong, smooth and self-centered. -perpetuating.
This is a video of a circuit responding to light and dark.
Step 3: To turn your light graffiti into a discardable work of art, we need to paste some rare earth magnets on the shell or circuit board.
I found that epoxy resin can protect magnets very well.
The magnet is firmly attached to it, and you can throw your image onto any metal surface.
With the power of magnetism, you can take your graffiti to places that you can't reach, where it can silently publicize your eternal propaganda without interference.
The fourth step is to show that we need this LED to light up our artwork.
Ordinary computer paper can be used at a critical moment, but the transparent film overhead is a good printable waterproof cover.
Print out your image and fix it in front of the LED.
Alternatively, you can change the circuit to allow the use of the entire graphics consisting of multiple LED lights!
If you're a totally evil person, you can replace the LED with a buzzer that rings every night until the end of time.
It's time to find a place of our own in the landscape of urban hell.
Metal buildings and bridges are great canvas.
If you can throw your graffiti high enough, it will take years.
Most lamp poles can block your lamp boards, but they are likely to be removed immediately.
Show us your graffiti. . .
What's the best place for these permanent art installations in your neighborhood?
Create your own and create a place for your eternal and brilliant works of art this weekend.
Post a photo on the cork board of this or any project to get a free lucid dream goggles kit!
As usual, if you have any questions, please feel free to post them on the forum, send me a message directly, or ask questions in the comments below.