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In this project we use an Arduino UNO/Nano to run a laser show with a laser pointer. We are using real galvos (galvanometers) like in commercial laser projectors, since these have become quite affordable recently (around 100 Euros/Dollars) 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 zoom/translate/rotate)
  • Logo rendering
  • Drawing effect (draw object or text incrementally)
  • Line clipping
  • Optimized for small program size (PROGMEM font/objects) 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:

https://www.instructables.com/id/Arduino-Laser-Show-with-Full-XY-Control/

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.

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 crocodile/alligator clips (to easier connect the laser pointer)
  • a breadboard or prototyping PCB
  • jumper wires
  • some Lego bricks (optional, for the laser mounting)
  • a box/casing 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:

http://www.ebay.de/itm/20Kpps-laser-scanning-galvo-scanners-ILDA-/201645259187

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).

Step 2: Laser Pointer

Hacking the laser pointer

For our project, we need to switch a laser pointer on/off from the Arduino. For this, you need to buy a cheap red laser pointer. It will typically have an on/off 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. The easiest will be to use two alligator clips, typically one on the spring (-) and one on the case (+).

Have a look at the images for an example laser pointer.

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. Of course you can use any other material to build it.

Step 3: Setting Up the 20 Kpps Galvos

The galvo set should consist of:

  • The two X/Y 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 220V/110V 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. In the next step, we will connect these to the Arduino / DAC outputs.

Step 4: Wiring the DAC and Laser Pointer

For this project we choose the MCP4822 DAC (as PDIP-8, to be breadboard friendly). It is available for 3-4 euros. It offers dual channel 12bit and there is an Arduino library available for it. It is connected to the Arduino via SPI and supports an additional LATCH pin which offers synchronous update of both channels. It will generate two output signals ranging 0V to 4.096V.

The following links to the datasheet for the DAC:

http://ww1.microchip.com/downloads/en/DeviceDoc/21953a.pdf

The wiring is done like shown in the images above.

The laser pointer is connected to GND and to Arduino pin D5. As said before, if you want to be on the safe side regarding drawing current from the Arduino, you can also use a transistor/MOSFET instead of a direct connection from pin D5.

The connection to the DAC is as follows:

Arduino CLK (pin D13) -> DAC SCK (pin 3)

Arduino MOSI (pin D11) -> DAC SDI (pin 4)

Arduino CS (pin D10) -> DAC CS (pin2)

Arduino pin D7 -> DAC LATCH (pin 5)

Arduino 5V -> DAC VDD (pin 1)

Arduino GND -> DAC VSS (pin 7)

This leaves us with DAC pin 6 and pin 8 which provide us with the two analog output signals.

One output of the DAC is connected to the ILDA driver card for the X galvo and the other one to the Y galvo. Since the ILDA driver cards expect a bipolar signal, in pricipal we would have to generate a signal from -5V to +5V and an inverted signal for the negative driver input. But these driver cards do not care so much about the bipolar signal, so you can wire each DAC output (with is positive 0 to +4.096V) to the ILDA IN+ connector and connect both the ILDA GND and ILDA IN- to the Arduino's GND. This will not drive the galvos to their full angle range, but it should already generate an image in about 1/4 of the galvos range. In a later step, we will learn how to create a correct bipolar signal.

In principle, this DAC is replaceable by any other dual channel DAC
that operates on 5V and supports latching, but you will need to adjust the Arduino sketch to make it work with a different DAC. The DAC code is inside of the Laser.cpp file.

Step 5: Housing / Putting Everything Together

If you don't have a box/case yet, now is a good time to get one. Don't forget to add an opening so that the laser ray can be emitted. I just used a wooden box and sawed a (too big) round hole and added a flap to open/close it. As you can see in the picture, I have plenty of room left, so I should have choosen a smaller box.

After everything is mounted, place the laser pointer near the galvos and adjust it so that it points into the center of the first galvo. I recommend to not fixate it at this point, so that you can re-adjust it later on.

The Arduino should be powered via USB, so you need to connect it to your PC (or later on to a USB charger) to run the laser show. You could also get the power from the galvo power supply, but this would require a DC-DC step down module, which is easy to add but out of scope of this project.

Your setup should look similiar to the one given in the image above, except for the extra (optional) amplifier PCB on the image, which will be explained later on.

Step 6: Software: Uploading the Laser Show to the Arduino

If you haven't already installed the Arduino IDE, now is a good time to do so.

You can download the complete laser show sketch from:

https://github.com/DeltaFlo/LaserProjector

  • Download the project (Just click on the "Clone or Download" button and choose "Download ZIP").
  • Open the LaserShow/LaserShow.ino sketch in the Arduino IDE.
  • Connect the Arduino via USB.
  • Press the compile and upload button.

If you wired everything as explained, the Arduino should now run the laser show right away.

Since the laser pointer does not have a lot of power, you will need a dark place to fully enjoy the show. Of course you can upgrade the project to a more powerful laser diode, but this is not covered in this tutorial and requires additional safety measures.

Trouble shooting:

  • is the laser pointer not switching on/off? Check if it is wired correctly.
  • is the laser pointer hitting the galvos in the right position? Try readjusting the height/angle of the pointer.
  • are't the galvos moving? Check if the power supply is working. Check if the galvos move when you connect +5V and afterwards GND to the positive input of the driver card instead of the output from the DAC.
  • is the image flipped horizontally or vertically? (adapt the Laser.h header file to flip the projection)
  • is the image rotated 90 degrees (adapt the Laser.h file to swap X/Y)

Fine Tuning:
Have a look at the Laser.h file to fine tune various timings to your hardware. Your laser pointer might have a smaller/bigger on/off delay than mine and the galvos might react differently.

The galvo driver cards typically also have potentiometers to fine tune over/under shooting, so you might play with those as well. In my setup I still had problems reaching the closing point of a contour exactly, probably because of the overshooting.

Step 7: Bipolar Signal With Opamps

NOTE: you only need to do this step if you want to get a bigger projection angle or if you are eager to learn how to generate bipolar signals and their inverse.

In the previous steps, we have already built a working laser projector, but we did not generate the correct bipolar ILDA signal that the driver cards expect. So how does a bipolar signal work? Bipolar means that the signal swings from -5V to +5V (so it has a range of 10V and GND is the center). In additional, the ILDA standard wants the same signal again as an inverted signal. For example a negative ILDA input of e.g. -5V requires a positive ILDA input of +5V.

Want we want to build now is an amplifier circuit which amplifies the unipolar DAC signal (from 0V to +4.095V) to the bipolar range -5V to +5V. For this we need a bipolar power supply. Luckily we can just use the power supply of the galvos, which is bipolar.

We are going to build the amplifier for X and Y separately, since it is the exact same circuit. To amplify an analog signal and to invert it, an opamp (operational amplifier) is used. Since we want to make the amplifier adjustable, we will add potentiometers for the gain and the offset, instead of fixed resistors. This makes the whole setup adjustable to different input ranges from the DAC and different power supply voltages.

Parts needed:

  • 2x TL082 opamp (PDIP-8)
  • 2x 1 KOhm resistor
  • 2x 47 KOhm resistor
  • 4x 10 KOhm resistor
  • 4x 10 KOhm potentiometers

The above images show the circuit for one signal line, you need to build it two times. I generated a circuit view and a breadboard view. I decided to put it on prototyping PCB together with the DAC, but that is totally up to you, breadboards will work fine as well. My PCB is shown on the last image.

Finally you need to connect the two DAC outputs to the two amplifiers and their +/- output to the ILDA driver inputs. Make sure that you also connect the GND of the Arduino with the GND of the galvo power supply, to get a common ground. Connect the power supply to the two amplifiers as well. Now everthing should be setup and you can run the laser show and adjust the image using the potentiometers.

How the amplifier works

One potentiometer is used for the GAIN (it scales the image) and the other for the OFFSET (it moves the image). The TL082 IC contains two separate opamps. One opamp is used to move and scale the signal (and also invert it), the output is the negative ILDA INPUT-. The second opamp is used to invert the signal again to get the positive ILDA INPUT+.

Step 8: Further Project Extensions

You can extend this project in various way. If anyone is interested, I plan to write additional instructables that extend this project:

  • Upgrade to a Teensy 3.2 microcontroller and create a live spectrum analyzer

    (https://www.youtube.com/watch?v=QLwdwvleztA)

    (Source code here: https://github.com/DeltaFlo/LaserProjector/tree/master/LaserSpectrumAnalyzer)

  • Add an ESP8266 to show content from the Web

  • Create an Etch-A-Sketch Webpage which sends the drawn sketch to the laser projector
<p>Many thanks for the great project. It is exactly what I was looking for. I plan to project a simple time and the date when needed to the wall. For that I have a rtc3231 with on the board provided. I have unfortunately a small problem. Why is everything twisted in x-direction? I have the opamps synonymous built according to your circuit. Pin 1 of the respective opAmp goes to ilda- and Pin 7 to Ilda + or do I have to invert one of them?</p>
<p>You can also invert x in the code, there is a #define in Laser.h to flip in x and y direction.</p><p>Funny, I actually did the same, the projector shows date/time, weather report and per date infos onto my bed room wall. I added Wifi so that it can get weather and other infos from the web.</p>
<p>Many thanks, that was the solution. In future I will also be able to spend a few more info, which is to be asked about an esp-12e module but unfortunately I still lack the necessary knowledge around the programming of the arduino. What do you think the use of a stm32 would reduce the flicker?</p><p>http://www.ebay.de/itm/like/252277680988?lpid=106&amp;chn=ps&amp;ul_noapp=true</p>
<p>... Or are the galvos too slow?</p>
<p>A faster micro controller helps a bit, I am using a Teensy 3.3 (or nowadays a 3.5). The nice thing is that it is almost 100% compatible with the arduino. But don't expect it to get much smoother (maybe a factor of two faster), the final limit are the galvos. When they are driven too fast, the lines get non-linear. You can try that with the Arduino already, if you change the quality parameter in Laser.h it will send less intermediate points and you can see the non-linear movement.</p><p>A Teensy works very nice to communicate with the esp over serial because it has two hardware serial lines. </p>
<p>Hi, I now have a teensy 3.5 but only the laser flickers. I have made the connections 1:1. There is no movement of the galvos. Where do I have to make changes to the sketch for the teensy? Can you please help me?</p><p>thanks</p>
<p>Did you connect the correct SPI CLK and MOSI pins to the MCP4822?</p>
<p>Thank you for your fast feedback.</p><p>Same Pin Numbers as Nano or Pro Mini</p><p>Teensy: 10 - CS0, 11 - MOSI0 , 13 - SCK0</p>
<p>Try disabling MCP4X_PORT_WRITE on the MCP library header file, maybe the port writing does not work on Tennsy 3.5?</p><p>On my Teensy 3.2 it worked out of the box, the only thing I had to change was the gain in the MCP library because the voltage is only 3.3V, but even witout changing the gain, you should see an image... If the galvos don't move it has to be the wiring of the MCP.</p>
<p>呃,can i use uno to enjoy it?</p>
<p>thank you but unfortunately did not help :-(</p><p>When compiling I noticed however:</p><p>Laser.cpp:155: warning: 'y' may be used uninitialized in this function </p><p> outcode1 = computeOutCode(x1, y1);</p><p>Laser.cpp:153: warning: 'x' may be used uninitialized in this function </p><p> x1 = x;</p><p>myLaserShow: In function 'void drawArduino2DRotate()':</p><p>myLaserShow:208: warning: unused variable 'hX' </p><p> long centerX, centerY, hX, hY, w,h;</p><p>myLaserShow:208: warning: unused variable 'hY' </p><p> long centerX, centerY, hX, hY, w,h;</p><p>myLaserShow: In function 'void drawScroller(String, float, int, int)':</p><p>myLaserShow:341: warning: comparison between signed and unsigned integer expressions </p><p> for (int c = 0; c &lt; s.length() + maxChar; c++) {</p><p>myLaserShow:367: warning: comparison between signed and unsigned integer expressions </p><p> if (c&lt;s.length()) {</p><p>Opening Teensy Loader...</p>
<p>No, I don't think it is those warnings...</p><p>Hm, try a minimum example with the MCP library and write 0 and 4095 </p><p>using dac.output2(value1, value2) and check if you get 0 and 3.3V on the outputs of the DAC.</p>
<p>I'm not quite sure but I think you mean at this position?</p><p>// Called by the output* set of functions.</p><p>void MCP4X::output2(unsigned short data_A, unsigned short data_B) {</p><p> data_A=0; data_B=4095; &lt;------------ i have put This </p><p>this-&gt;output(MCP4X_CHAN_A, data_A);</p><p>this-&gt;output(MCP4X_CHAN_B, data_B);</p><p>I Have only 0V and 2V on the Output Pin6 and Pin8 on DAC</p><p>Can a level shifter help here?</p>
<p>Uups, with an Arduini ProMini i have the same Results :-O</p><p>0V and 2V</p>
<p>I have made 2 pictures with my mini osziloskop. These are the start sequences after the turn on. Can do with the fact that the Teensy with 120MHz. Is clocked?</p><p>Picture1 ProMin</p><p>Picture2 Teensy 3.5</p>
<p>Probably the Teensy is so fast that the galvos don't move at all.</p><p>2V is fine, because the MCP only gets 3.3 V and if gain is set to 1X, you get 0 - 2.047V instead of 0 - 4.096 with gain 2X and 5V. Gain 2X does not work with 3.3V because the MCP can not go above 3.3V, so the output will be clamped.</p><p>Regarding the speed, yes, you need to adjust the Laser.h parameters:</p><p>improve the quality:</p><p>#define LASER_QUALITY 8</p><p>enable the move delay:</p><p>#define LASER_MOVE_DELAY 5</p><p>Try putting laser quality between 1 - 16 and laser move delays between 1 - 10.</p>
<p>Another thing, the MCP library uses the old deprecated SPI API to set clock speed, see</p><p><a href="https://www.pjrc.com/teensy/td_libs_SPI.html" rel="nofollow">https://www.pjrc.com/teensy/td_libs_SPI.html</a></p><p>for details. This means the SPI speed depends on the MHz of your Teensy. Try compiling with 96Mhz (which is what I used with my Tennsy) instead of full speed. Alternatively the SPI init code in the MCP library could be changed to use SPISettings and SPI.beginTransaction() to specify a fixed SPI clock rate across all micro controllers.</p>
<p>Thank you for your great support. the speed was only a part of problem that is now solved. I can now work well with the parameters. The main problem I was myself! I didn't notice that I've given voltage at the teensy about 6V. Thus he is not properly run and gave no values at the SPI port for the DAC. </p><p>I didn't notice that because I've programmed only on the PC with a USB and after that i put the teensy in the circuit. Now something is blown on the teensy but it works anyway.</p><p>I would like to apologize for my mistake which has made you so much unnecessary work!</p><p>Many Thanks for your Help.</p>
<p>You are welcome, no problem! I am happy you solved it.</p>
<p>OK, thank you. I have unfortunately no teensy to try. I will try to port it on a stm32. But basically it is not tragic, because I want to represent anyway only a static text without animations. My problem is at the moment, that I still do not know how I should represent several lines at the same time. For a tip I would be grateful.</p><p>Apologize my bad english, I communicate via babelfish translater.</p><p>best regards</p>
<p>You can draw multiple lines using multiple calls to</p><p>Drawing::drawString(text, x, y);</p><p>inside of a loop. The more you draw, the slower it gets ofcourse.</p>
<p>I will try to see if I can do it. Because of the pcb. I have it on my milling machine and still have 2 with small errors, which are however not tragic. do you live in Germany? I can send this pcb-board if you want</p>
<p>By the way, I really like the PCB you designed. That is completely outside of my skills!</p>
<p>thank you, I will try to see if I can do it. Because of the pcb. I have it on my milling machine and still have 2 with small errors, which are however not tragic. do you live in Germany? I can send this pcb-board if you want.</p>
<p>That's really nice of you! But I don't really need it since I am not going to build another one. Big thanks anyways!</p>
<p>Just made it - works perfectly! I did Arduino nano and Tennsy and have a switch before ILDA amplifier to select the source. Arduino provides the original presentation and Teensy spectrum analyser :) I also added a tactile button to switch between Analyser modes in more controlled fashion :)</p><p>Great thanks for whole idea and source code!</p>
<p>Cool! I like it!</p>
<p>Hi, trying to create own drawings. I managed to get a png into paths and exported it in svg format (using Gimp). What kind of tools have you used to convert svg to gcode (if at all ;) ) ?</p><p>If you have not been using svg - what was your drawing development toolachain or process to create a new drawing?</p><p>br,</p><p>Greg</p>
<p>Hm, I used a custom software from my work (which I can't share).</p><p>But you can search for Python libraries that convert SVG to Gcode and use that to convert SVG. Alternatively you could change such a library to directly output the format for the laser, which is just on/off and 15bit x and 16bit y.</p>
<p>Hi,</p><p>thanks for information :) I found a converter from SVG to Gcode - <a href="https://www.cnctoolsworld.com/application-all_to_g_code_converter_free-2.html." rel="nofollow">https://www.cnctoolsworld.com/application-all_to_g...</a> It's quite ok, the only thing I need yet to work out is how to avoid getting too many points on path generated out of my SVG...</p><p>br,</p><p>Greg</p>
<p>Hello I am from bangladesh .. I wanna make this project ... for my department <br>I have few question :<br>1. will it run by arduino mega ?<br>2. u make the pin 5 for laser .. .for example code is there will be any difficulty if all connections are made carefully.. ? I mean complexity chances are high or low ?</p>
<p>Yes, you can get it to run on an Arduino Mega, but it would definitely be easier if you just buy a Arduino Nano (clones only cost 5 Euros).</p><p>If you use a Mega you will have to:</p><p>- change the pins for SPI:</p><p>Arduino Nano: pin 11 instead goes to pin 51 on Mega</p><p>Arduino Nano: pin 13 instead goes to pin 52 on Mega</p><p>- you have to REMOVE this line in mcp library AND in Laser.cpp:</p><p>#define MCP4X_PORT_WRITE 1</p><p>- to use different pins for the laser, the latch and cs, you can select any digital pin on the Mega and change the code at Laser.cpp</p><p>dac.init(..., 10,7,1)</p><p>Replace 10 with your Mega pin you choose for CS, replace 7 with your latch pin.</p><p>This leaves us with the pin for the laser, that is specified in LaserShow.ino in the constructor of Laser().</p>
<p>Hello Florian, I follow your project very long. </p><p>I would also like to use another processor, the STM32 for the control because it is very small, very cheap, very fast and 99% arduino compatible. </p><p>You write for use with the Mega: &quot;#define MCP4X_PORT_WRITE 1 - you have to REMOVE this line to mcp library AND in Laser.cpp:&quot; </p><p>If I have understood correctly, this definition is nevertheless responsible for PORTB and accelerates the output. </p><p>Why disable PORT_WRITE 1?</p>
<p>... or otherwise asked, Pin10 of Uno or Nano is PB2. Pin10 of Mega is PB4. Can I use &quot;PORTB | = (1 &lt;&lt; 4)&quot; instead of &quot;PORTB | = (1 &lt;&lt; 2)&quot; and &quot;PORTB &amp; = 0xEF&quot; instead of instead of &quot;PORTB &amp; = 0xfb&quot;? I do not know if I am on the right track or completely wrong. I am really concerned that the function PORTB does not exist in STM32. Here I can bit manipulations with &quot;GPIOA ... GPIOB ...&quot; etc. work. I would like to take over, so my question.</p>
<p>well, disabling the port write will use digitalWrite(), which does not have to be slow depending on the target platform. It is slow on the Arduino, so portwrite is more direct that digitalwrite. But if the portwrite is emulated, e.g. on the Teensy, then it does not bring any performance improvements.</p><p>Of course you can optimize the MCP library for your target platform, so you can adapt it to portwrite on the Mega as well or to specific STM32 functions/ports. But as the first step to get things working cross platform I would turn the portwrite off and see how good it works with digitalWrite.</p>
<p>thank you, i will try</p>
many thanks.for reply. the galvos are coming by shipment... hope that everything should run without any disturb :) :)
<p>I have a another question if u dont mind .. <br>1. What is the dimension of the text in real world ? something 1 feet by 1 feet ? If not is there any solution to increase the dimension like putting the box in distance around 20 feet or 15 feet from the wall ...or using glass .. <br>2. The galvo comes with the scanner which can scan sd card files for laser show .. and display that .. how that works ? i see some examples that by some softwares raw file is designed and mounted in the SD card and then scaned , displayed by ILDA... is this possible... In this particular case is there no need of laser pointer ? Or how efficient that method is ??</p>
<p>I don't know what you have ordered. Maybe you can post a link to the scanner you ordered? It sounds like it vontains more than the galvos and the driver cards.</p>
<p><a href="https://www.aliexpress.com/item/20K-Laser-Galvo-Mirror-w-Power-supply-program-board-IC-Animation-laser-light/32407806023.html?spm=2114.10010108.1000013.2.CDgtVx&scm=1007.13339.33317.0&pvid=ec0f5272-1f3d-4fd0-8637-6e59e50ddacb&tpp=1" rel="nofollow">https://www.aliexpress.com/item/20K-Laser-Galvo-Mi...</a> <br><br>This item comes with scanner</p>
<p>Yes, looks like it contains a controller that can play animations from SD card, although it does not explain anything on how to do that. But I did not see a laser on the item list, so you still need a laser pointer or laser module to do the show. You don't need the controller part, that will be done by your Arduino.</p>
<p>oooo is this module is okay to set up with ur project...? I am little bit tensed... and whats about the real dimension of text ? pls </p>
<p>Yes, it should work, but you don't need the controller card which comes with it. The size depends on the angles the galvos can move to and the distance to the wall/projection surface, a typical angle for the galvos is 10 degrees. So you can project on your neighbors house and it will be a big projection but of course for large projections the laser pointer might not be powerful enough.</p>
Spectrum analyser looks really cool. Much better than any other I have ever seen. Really great idea to make it laser based. Looking forward for your instructable for it:)
<p>I uploaded the source code for the spectrum analyzer to Github, I am not planning to write an instructable on that. It is basically just replacing the Arduino Nano with a Teensy 3.2 / 3.5 and adding an audio input circuit. Since the Teensy is very compatible, it is straight forward to switch from Nano to Teensy,</p>
Ach, OK,<br><br>Thanks for the code on github. I will figure out all that is needed from there :) I'm going to build the projector directly based on teensy 3.2. Thanks a lot for all tje code and setup!<br><br>Br,<br>Greg
<p>This was a lot of fun! Thank you for all of the time you put into it and for sharing it with the rest of us. While testing the circuit before hooking up the galvos and laser, for giggles I put the oscilloscope in x-y mode. Sure enough, the images appeared on the scope screen! I hope you will share more projects with us in the future. Cheers!</p>
<p>Cool! I like the oscilloscope idea!</p>
<p>Yeah, it looks pretty cool. Now I have to order a Teensy to speed things up a bit. Any tips? I have never used one before. Should I get a 3.2 or a 3.5? Also excited about your spectrum analyzer. Will you be making an instructable for that?</p><p>Cheers</p>
<p>I used a 3.2, but you should get a 3.5, I think. There is no reason to get a Teensy 3.2, because it is not much cheaper than the 3.5. The source code for the Laser works out of the box, the only difference is that the Teensy is 3.3V so you need to change the gain in Laser.cpp and you need to change the timings because the Teensy is much faster.</p><p>Regarding the spectrum analyzer, I don't have plan for an instructable at the moment, but I can send you the source via private mail if you want.</p>

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Bio: I'm a software guy, starting to learn electronics.
More by DeltaFlo:Arduino Laser Show with real galvos 
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