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thatguyer

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  • DIY "Faux" Live Edge River Coasters

    OK, my attempt at the ocean wave cutting board was a fail, but this one turned out better. I used some wood from a downed tree near my house...

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  • DIY Resin Ocean Serving Tray

    I feel like I should post this photo next to yours on one of those "Nailed it!" Subreddits... :-)

    Luckily this was just a piece of scrap plywood, so nothing was lost (I know how this goes!)

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  • DIY Resin Ocean Serving Tray

    This is such a cool project. I have done a lot of woodworking/maker stuff, but I'm relatively new to epoxy. I did some experiments today, with mixed results. The blue water came out fine, but the waves don't look good. Using the heat gun, the white spread over the blue too uniformly, and did not create that lacy look. Are you using white paint directly, or is it white epoxy (white pigment in epoxy)? Any other tips or tricks to share for the waves? Thanks!

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  • thatguyer commented on thatguyer's instructable The Algorithm Machine
    The Algorithm Machine

    Yes! Sorry about that. You can find them here:https://www.thingiverse.com/thing:4178181This STL file has two 10-LED modules, so you need to print it five times to get a total of 10 modules.

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  • thatguyer commented on thatguyer's instructable The Algorithm Machine
    The Algorithm Machine

    Nice job. It took me a lot longer than that! I'm still making improvements to the software, so keep an eye on the GitHub repo.

    Wow, I'm impressed. It took me a lot longer. ;-)I'm still making improvements to the software, so keep an eye out on the GitHub repo

    Wow, I'm impressed. It took me a lot longer. ;-)I'm still making improvements to the software, so keep an eye out on the GitHub repo

    Wow, I'm impressed. It took me a lot longer. ;-)I'm still making improvements to the software, so keep an eye out on the GitHub repo

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  • thatguyer commented on thatguyer's instructable The Algorithm Machine
    The Algorithm Machine

    Great! Tell me more about it -- did you build the whole thing? You should be able to set NUM_LEDS to however many you actually have. The sketch will adapt as necessary.

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  • thatguyer commented on thatguyer's instructable The Algorithm Machine
    The Algorithm Machine

    Hi! All of the buttons are just simple momentary pushbuttons. I used a big button for start/stop, but there is nothing else special about it. Just make sure all of the buttons have pull-down resistors from the input pin to ground.This device uses very little power, especially since most of the indicator LEDs are off at any given time. I just use a 2A or 3A 5V DC adapter (the kind of thing you would use to charge a phone or tablet).

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  • thatguyer's entry The Algorithm Machine is a winner in the STEM Contest contest
  • thatguyer's instructable The Algorithm Machine's weekly stats:
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  • thatguyer commented on thatguyer's instructable The Algorithm Machine
    The Algorithm Machine

    Thanks! I felt the same way. Even when I did finally really understand it, I still couldn't picture exactly what was going on!

    Thank you! Some of my first programming experiences were on a VAX 11/780, so I'm familiar.What you're describing is a variant of radix sort (https://en.wikipedia.org/wiki/Radix_sort). In the form you are describing it is asymptotically faster than any other sorting algorithm ( order N versus order N*logN), but it comes at the cost of space (memory use): the size of the counting array is exponential in the number of bits in the values you're sorting. So, sorting 8 bit values requires 256 counters, sorting 16 bit values requires 65536 counter, and sorting 32 bit values requires around 4 billion counters. Forget about 64 bit values!One strategy to make it feasible is break each value into groups of bits and perform radix sort at each level. You could think of it like sorting numbers by placi…

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    Thank you! Some of my first programming experiences were on a VAX 11/780, so I'm familiar.What you're describing is a variant of radix sort (https://en.wikipedia.org/wiki/Radix_sort). In the form you are describing it is asymptotically faster than any other sorting algorithm ( order N versus order N*logN), but it comes at the cost of space (memory use): the size of the counting array is exponential in the number of bits in the values you're sorting. So, sorting 8 bit values requires 256 counters, sorting 16 bit values requires 65536 counter, and sorting 32 bit values requires around 4 billion counters. Forget about 64 bit values!One strategy to make it feasible is break each value into groups of bits and perform radix sort at each level. You could think of it like sorting numbers by placing them into bins according to each digit, starting with the highest place value. For example, to sort values in the range 0-999, you start by putting each value into one of ten bins according to the digit in the 100s place. Then consider each of those bins, and further divide them into ten bins for each digit in the 10s place. Then continue down to the 1s place. At any given time you only need some multiple of 100 bins (much much less than the exponential-sized algorithm).In this form, radix sort runs in time N * d, where d is the number of digits in the largest number. Since d is always some log factor of the size of the values, however, it ends up being N * logN in practice.

    That's a great idea. I should put together a web app. In some ways it can do a lot more than a physical device (like change the number of elements in the array)

    Thank you!

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  • thatguyer's entry The Algorithm Machine is a finalist in the STEM Contest contest
  • thatguyer commented on thatguyer's instructable The Algorithm Machine
    The Algorithm Machine

    Yes! I am making a bunch of videos today, so I'll post them as soon as I'm done. I was racing to get it done yesterday, so I didn't have time.

    Just added a video showing bubble sort, insertion sort, quicksort, and merge sort.

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  • Creepy Creature Quad Stilt

    Are there actual instructions somewhere here?

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  • I love the idea of a 3x3 wall of these panels, but seriously, that is a professional-level project (at a professional-level price, too!). I recommend starting small and building up. That's what I did. The first version of this table had just one LED ring and one motion sensor. Once I had that system figured out, I scaled up to around 20 rings, then later to 60 rings. It takes a lot of patience and perseverance, but it pays off!

    Anything is possible! I don't have any experience using audio to control the animation, but I have seen a lot of discussion on various forums about how to do that. If you're not going to have motion sensors you can save yourself a ton of work on the build!WiFi configuration should be pretty straight forward, but you need to know how to use the WiFi libraries.

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  • thatguyer commented on TheTNR's instructable VORONOI HEART LAMP

    I made something similar for my wife for Valentine's Day. I wrote an Arduino sketch that pulses the heart in a realistic way -- I grabbed real data from an EKG! Let me know if you want to try it out on yours.

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  • Sounds like a bug of some sort, but I haven't seen anything like that. Can you tell me more about the hardware setup you have?

    Wow, beautiful! I love the wood and the shape. And the diffuser on the LEDs looks great. What material is it?

    Can you send me your modified code? I'll take a look

    Hi! Sorry it took me so long to reply. Typically, you get that message if you have a short somewhere in the circuit. Sometimes it happens if you try to power the hourglass completely from the USB port, but that is less likely. Unplug everything and check the connections. In particular, look for places where you might have accidentally reversed the polarity -- that is, plugged a wire that supposed to be 5V into the ground, and vice versa. That is the most common cause; I've done it many times myself!

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  • I'm interested. I also have someone else who is interested in a modular design that they could use to build a much bigger installation (like a whole wall!). You can reach me directly at sam.guyer@gmail.com

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  • Here's an instructable describing how to build a table using the Evil Mad Scientist modules:https://www.instructables.com/id/Interactive-LED-t...

    I have seen some products like the one you describe, but for the simpler discrete LED table. The problem is that they aren't cheap -- but maybe having them made yourself would be cheaper. Here's an example:https://www.evilmadscientist.com/2011/octolively-d...I tinkered with making a hand-built module for a single "cell", but it seemed like more trouble than it's worth. A pre-fab PCB would be cool.Another wacky option would be to have a tiny MCU on each cell, so it is completely self-contained, except for power.See the attached photos of the enclosure that I built (you'll see a rotary encoder on there, too, but right now it doesn't do anything).

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  • Great questions. The PIR sensor sounds like a good idea to save energy and probably extend the lifetime of the panel.I've been thinking about many of the same things because I'm hoping to make a wall panel as well! You are absolutely right that the 3-wire jumpers add a lot of depth. What I did is create more of a box, with the LED panel as the top and a sheet of 1/4 MDF for the bottom. I bolted them together with aluminum spacers and beams to make room for the jumpers. This also leaves plenty of room to attach the MCU and the power supply to the MDF board under the panel.The layers from top to bottom are:(1) plexiglass(2) diffuser (usually very thin)(3) Thin strips of wood a little thicker than the height of the IR sensors/emitters, so they don't get squished.(4) Cardboard panel with LED …

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    Great questions. The PIR sensor sounds like a good idea to save energy and probably extend the lifetime of the panel.I've been thinking about many of the same things because I'm hoping to make a wall panel as well! You are absolutely right that the 3-wire jumpers add a lot of depth. What I did is create more of a box, with the LED panel as the top and a sheet of 1/4 MDF for the bottom. I bolted them together with aluminum spacers and beams to make room for the jumpers. This also leaves plenty of room to attach the MCU and the power supply to the MDF board under the panel.The layers from top to bottom are:(1) plexiglass(2) diffuser (usually very thin)(3) Thin strips of wood a little thicker than the height of the IR sensors/emitters, so they don't get squished.(4) Cardboard panel with LED rings and IR emitters/sensors (analog multiplexers are glued underneath)(5) Aluminum L-shaped track to support the cardboard (along the long edges, but you could make a box)(6) Aluminum tubes cut to about 2 inches for spacers -- should be plenty of room for the jumpers.(7) MDF board hold the MCU and power supply.2 1/2" or 3" bolts go through all the layers (and through the spacer tubes) to hold it together. It's surprisingly sturdy. I'll take some some photos this evening and put them up.Going forward, I might try to chain the LED rings together in a different way to reduce the thickness of the assembled panel. I'm not exactly sure how, though. One of the side benefits of my original scheme is that the three-pin headers on each LED ring do a great job holding the in place in the correct orientation, even when the panel is held vertically, so there is no need for hot glue or any permanent attachment (which was also good because a couple of the rings had dead pixels!) I'd have to think about where to put the power supply, but it doesn't need to be right on the panel itself if you're not going to move it around a lot.

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  • Oops! Those were separate libraries. What I did is just copy the contents right into VizTimer.ino. I just pushed the changes to GitHub, so if you update your repo you should get a copy that compiles. Sorry about that!

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    • VizTimer: the Electronic Hourglass
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  • Switching to the TTP223 is no big deal -- it has the same pins. Using the ADXL345 is more complicated because it uses digital output (I2C) instead of analog output. The wiring would be a little different, but you would need to change the code more, too.

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  • Funny comment -- thanks!Yes, you can definitely build this project with an Arduino Nano. It is almost identical to the Adafruit Metro that I used. In fact, you can use any microcontroller that runs on 5V and has at least 3 analog inputs, 1 digital input, and 1 digital output.

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  • Thanks!

    I hear you. You can find all the same things at AliExpress:Microcontroller: https://www.aliexpress.com/item/5LOT-Funduino-Nano...Accelerometer: https://www.aliexpress.com/item/GY-61-ADXL335-Modu...Capacitive touch button: https://www.aliexpress.com/item/10Pcs-TTP223-Touch...LED strips (get 144/m): https://www.aliexpress.com/item/1m-4m-5m-WS2812B-S...

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  • I don't know the exact number. It depends a lot on the particular pattern and on the global brightness level set in the software. I have a 30amp power supply, but I'm guessing that most patterns use less than 5amps

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  • I use a Mac with High Sierra, and I have not had problems. What are you seeing? Is it a problem with the Arduino IDE recognizing the board?I am guessing that Mega would also work. The only issue is making sure you have enough pins. You need at least four analog inputs for my design -- fewer if you build a smaller surface.

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  • Oh man, I made that same mistake a bunch of times! Looking at your first photo, the horizontal and vertical lines look great, and the angle of the diagonals is right (up 3 and over 1). HOWEVER, they are not close enough together. If you follow a single vertical line up, there should be an intersecting diagonal every *two* units (every 60mm), not every three units. Look at Step 11 again, in particular the fourth photo that shows just two diagonal lines. Does that make sense?Also: do you have a plan for making all of those little holes in the plywood? It could be a huge pain!

    If the LEDs are definitely 1.2V 20ma, then I'd probably go with something like 47 Ohm resistors. It's pushing them a little bit.But LEDs vary quite a bit, and resistors are really cheap, so I would recommend getting the LEDs and figuring out the best resistor yourself using a multimeter.

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  • I found it confusing, too. You want the ones with female (socket) connectors on both ends. Sometimes the sellers call these male-to-male connectors because they join things that have male connectors on them. Just look carefully at the pictures before you buy anything.

    It depends on a lot of factors, but mine is sensitive up to 3 or 4 feet away. The factors that influence sensitivity are the power of the emmitters, how reflective the object is (eg, your hand vs a piece of white paper), and whether or not you have a diffuser over the surface. I used a minimal diffuser for exactly this reason.

    That's a good point. I found some IR emmitters that are more powerful and have a voltage drop more like 1.5v to 1.6v. I found it better to just try out different resistors and measure the current directly with my multimeter. I'll update the discussion. Thanks.

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  • I found this confusing myself. The connectors you need are ones that have female (socket) connectors on both ends. But the way the sellers describe them is as male-to-male connectors, since they attach to male connectors. So, the link is correct, though somewhat confusing. Hope that helps!

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  • thatguyer's instructable NeoPixel Reactive Table's weekly stats:
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  • It will mainly affect the sensitivity of the surface. I assume that the smaller IR emitters produce less light. With less infrared light emitted, there is less to reflect back to the sensor, so you might have to put your hand closer in order to trigger it.

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  • Thanks! The rings are very cool. When you're ordering some, look carefully at the arrangement of the solder pads on the bottom -- there are a few different schemes I've seen. I used rings with two sets of three pads, which makes it relatively easy to string them together. Good luck!

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  • Just a minor comment on the wording: saying "don't go below 14awg" might be misleading to people who don't realize that higher numbers are actually thinner wires

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  • thatguyer commented on thatguyer's instructable 100 Watt Light Saber

    I can send you whatever files you need. I don't have a wiring diagram, per se, but all the connections can be determined in software. What's your skill level in electronics? Do you have the equipment to assemble a surface mount PCB?

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  • thatguyer commented on thatguyer's instructable 100 Watt Light Saber

    Thanks. I'm trying to get all the information together, but "work" is getting in the way! ;-) Aside from the blade, the electronics consist of four main parts: a Trinket Pro (from Adafruit) to run the program, a DFPlayer (from DFRobot, or one of the millions of clones) to handle the sounds, a gyro/accelerometer (you can get a breakout from Adafruit) for the motion, and an LED controller. Of all of the these parts, the LED controller is the most specialized. I ended up designing a custom PCB using Eagle and getting it made at OSHPark. It consists of a PCA9685 PWM controller and a bunch of N-channel MOSFETs to switch the higher power/voltage. I'm happy to share the project files. You can also just order the board directly here:<a href="https://oshpark.com/shared_projects/6…

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    Thanks. I'm trying to get all the information together, but "work" is getting in the way! ;-) Aside from the blade, the electronics consist of four main parts: a Trinket Pro (from Adafruit) to run the program, a DFPlayer (from DFRobot, or one of the millions of clones) to handle the sounds, a gyro/accelerometer (you can get a breakout from Adafruit) for the motion, and an LED controller. Of all of the these parts, the LED controller is the most specialized. I ended up designing a custom PCB using Eagle and getting it made at OSHPark. It consists of a PCA9685 PWM controller and a bunch of N-channel MOSFETs to switch the higher power/voltage. I'm happy to share the project files. You can also just order the board directly here:<a href="https://oshpark.com/shared_projects/6GX19Svs"><img src="https://oshpark.com/assets/badge-5b7ec47045b78aef6eb9d83b3bac6b1920de805e9a0c227658eac6e19a045b9c.png" alt="Order from OSH Park"></img></a>The alternative is to use the PWM pins on the microcontroller, but you'll still need to control the LEDs indirectly through power transistors.There's also a huge, crazy world of lightsaber builders (way beyond what I'm doing here!). You can find really good tips at https://www.fx-sabers.com/

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  • Nice description! Two things that I've found helpful. First, like you, I prefer to cut the tails first, since the angles don't matter much. The crucial detail, though, is that the saw must be perpendicular to the face of the board, otherwise the tails have a slightly different size/shape on the two sides, which can mess up the scribing of the pins. Second, I saw a nice trick (in Fine Woodworking, I think) for helping with the pins. One of the issues is that it can be hard to get a clean line on end grain. What they do is put a strip of blue painter's tape across the end of the board, then trace the tails onto the pins with a sharp knife. Peel away the parts where the tails will be, and you're left with nice clean pieces of tape where the pins should be.

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  • thatguyer commented on thatguyer's instructable 100 Watt Light Saber

    Hi! Thanks. I will be updating this instructable or writing a new one soon. I'm just waiting for all the parts to arrive. The COB LEDs came from aliexpress. The ones I used are only 6cm long, so I needed a lot of them. At $1 each, the LEDs were around $40. Here is the link:https://www.aliexpress.com/item/NEW-10pcs-3v-3w-L6...All-in-all, this is not a cheap project to make. The goal was to make something super-bright, regardless of the cost.I'm working on a more complete parts list now. Stay tuned!

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  • thatguyer commented on thatguyer's instructable 100 Watt Light Saber

    Incidentally, that's only about 60% of the theoretical max brightness. I started to get a little worried about safety.

    UPDATE: Here is a video of the completed saber:

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  • thatguyer commented on thatguyer's instructable 100 Watt Light Saber

    Thanks! I'm trying to get the whole thing finished in time for Halloween, but my plan is to post a more detailed instructable with information about how to build the handle, details on how to choose and assemble the electronics, and a complete set of design files (including the code to drive it).

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  • thatguyer commented on spaktashabit's instructable Simple Lightsaber

    I've made a few saber blades this way, and there are some useful details that you should mention. First, the LEDs are actually wired in parallel, not in series. Sometimes this can cause a problem when you don't have a current-limiting resistor on each one, but I found that if you buy all the LEDs together they are pretty well matched. Second, it is really, really important to get them all oriented the same way (all the anodes on one side, all the cathodes on the other side). Once you bend the leads it is hard to see which one is longer, so what I did is first put a little mark on the cathode side of all the LEDs with sharpie. Third, you didn't mention how you're powering the blade. The blue LEDs usually pull 20-30mA each at around 3.2V-3.4V. With 110 of them, that's 2-3 amps! I've found t…

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    I've made a few saber blades this way, and there are some useful details that you should mention. First, the LEDs are actually wired in parallel, not in series. Sometimes this can cause a problem when you don't have a current-limiting resistor on each one, but I found that if you buy all the LEDs together they are pretty well matched. Second, it is really, really important to get them all oriented the same way (all the anodes on one side, all the cathodes on the other side). Once you bend the leads it is hard to see which one is longer, so what I did is first put a little mark on the cathode side of all the LEDs with sharpie. Third, you didn't mention how you're powering the blade. The blue LEDs usually pull 20-30mA each at around 3.2V-3.4V. With 110 of them, that's 2-3 amps! I've found that the limiting factor on brightness is the internal resistance of the battery. You can switch to a high-drain 3.7V LiPo battery (like the ones for remote control vehicles) to boost the power. Although the voltage on a LiPo is a little high (especially when fully-charged), there is enough voltage drop along the LED string that it ends up being OK.Finally, if you want to take this design to the next level, you can wire the LEDs into separate segments and light them up in sequence using a microcontroller. Most microcontrollers cannot provide that kind of power directly through a ping, though, so you need to use a transistor (use a MOSFET) to switch the power.

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  • Another interesting option, if you haven't seen it, is the chip-on-board (COB) lights. I've been tinkering with the 12V strips that are sold as car accent lights. A 17cm COB can contain as many as 80 discrete LEDs, producing a very uniform light without needing a lot of added diffusion. Try searching for "cob led" on eBay. I pull off the outer frame and assembly, and re-solder them into various configurations. Cutting them is tricky because the underlying PCB has a peculiar circuit pattern, but I have been able to do it. They are ridiculously cheap -- $3 - $4 for a pair.

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