In the next step, we will connect these to the Arduino DAC outputs.We are using real galvos (galvanometers) like in commercial laser projectors, since these have become quite affordable recently (around 100 EurosDollars) and provide a much higher quality than speakers or stepper motors.Hardware On the hardware side, we build the Arduino driven projector by using a external 12Bit DAC (digital to analog converter) and an (optional) amplifier circuit to create the signal for the galvonometers.You can build this project if you have some basic experience with an Arduino board and a breadboard.You can get away without any soldering, although it is probably a better solution to solder a PCB finally.
Software On the software side, a complete Arduino sketch is provided which features: Text rendering (including zoomtranslaterotate) Logo rendering Drawing effect (draw object or text incrementally) Line clipping Optimized for small program size (PROGMEM fontobjects) and speed (fixed-point arithmetic) And a 3D cube that is rendered live. All source code is provided and can be easily adapted to create your own show Inspiration further reading I was originally inspired by the following project, which explains quite well how laser projectors work and which uses speakers to simulate the galvos: Using speakers is very limited regarding quality and complexity of the objects you can draw, which is why we use real galvos in our project. Laser Show System Driver Cards AndAdd Tip Ask Question Comment Download Step 1: Parts You Need an Arduino UNO Nano (or a compatible clone) USB power 20Kpps galvos with driver cards and power supply (these typically come in a set, see below) a 220V or 110V power cord (if galvo power supply does not come with a cord) MCP4822 DAC (a cheap dual channel 12 bit DAC) a red laser pointer some crocodilealligator clips (to easier connect the laser pointer) a breadboard or prototyping PCB jumper wires some Lego bricks (optional, for the laser mounting) a boxcasing to mount the project (optional but recommended) If you want to build the (optional) ILDA amplifier, see the parts list in the amplifier step. The most expensive parts of this project are the 20Kpps galvos. I bought my set on ebay: Just search the internet ebay for 20Kpps galvo and you should find an adequate set. These sets typically come with a bipolar power source (mine uses 15V-15V, if yours is in the range of 12-15V it should not make a difference). Add Tip Ask Question Comment Download Step 2: Laser Pointer Hacking the laser pointer For our project, we need to switch a laser pointer onoff from the Arduino. It will typically have an onoff push button, which you need to fixate to a permanent pushed state. On my pointer, I just used duct tape to permanently press the button. Next you need to remove the battery case (back part of the pointer) and add power supply wires instead of the batteries. ![]() Testing To test the pointer, you can connect it like this: Arduino 5V - Laser, Arduino GND - Laser - If your laser pointer draws too much current to be safely connected to the digital output of the Arduino, you have to use a transistor or MOSFET to switch it. My pointer worked without problems, so it probably draws less than 50mA. Mounting The pointer needs to be at the correct height to point into the galvos, for this you need to build some holder. I used some Lego bricks to build the holder, see above picture. Add Tip Ask Question Comment Download Step 3: Setting Up the 20 Kpps Galvos The galvo set should consist of: The two XY galvos with mirrors (attached to a metal block) Two identical driver boards, on for X and one for Y A power supply Connector cables to wire everything Extra input connector cables Power supply In my set, the power supply did not have a power cord, so I added a standard 3 wire power cord (I used an old PC power cord and removed the PC connector). Be careful when you work with the power supply, since it works on AC 220V110V and this is (as you should know) DANGEROUS I recommend that you get some kind of box to mount everything in and reserve an extra isolated spot for the power supply. I glued a plastic box on top, covering the power supply so that nobody can touch the high voltage input. Connecting everything Now connect the cables from the power supply to each driver card and each driver card to one of the galvos. You should have two remaining connector cables, which you can plug into the ILDA input of each card. You can either use these connector cables or instead you may use individual female jumper cables instead.
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