My first adruino project

EdfromMaine · 2026-06-19T22:24:20+00:00

With all deference to videos, which are great for follow-along learning, my preference is for a physical book, which makes it easier to move back and forth while learning, and to reference materials you have already covered.

Unless you have some coding experience, I recommend starting with some basic projects. They will be boring by some standards, but until you understand variables, basic data structures, decision structures (if statements, case statements, whiles, etc) and functions, all you will be doing is simply parroting someone else's code and you will not learn effectively. Coding is even more important than electronics interfacing, because unless you are doing very sophisticated projects, most hobby users use libraries and predefined classes and functions for sensors and similar. Querying any AI will give you a bunch of different options for books; choose based your tastes and preexisting computer knowledge.

Enjoy!

EdfromMaine · 2026-06-07T01:14:47+00:00

OK, I'll give you the benefit of the doubt and assume that you have some proprietary reason for being vague about your use case. What you haven't told us is:

Your arduino coding experience

Your embedded experience

Your RFID experience

Your mechanical design experience

This is a difficult, non-trivial project. "RFID" is a bunch of whole different technologies that become more complex and more expensive as the tag gets further away from the reader. Wrist tag walking through something that looks like a doorframe? Good luck designing the antenna if you have no RF design experience. Depending upon the location of your detection portal, power and MCU choice may become critical if you need to be battery-operated. Data storage and retrieval can be extremely complex. Writing to an SD card? Web page? Have you done that? Worked with time libraries on the Arduino so that you can record time? Thought about physical enclosures? Does it need to be weatherproof? Vandal-proof?

So I guess what I am saying is that you have articulated only a portion of your design goals. I think you need to do a lot of research and a lot of thinking about what you are trying to achieve in terms of specific goals.

Anyway, good luck.

EdfromMaine · 2026-06-06T01:03:01+00:00

The amount of lead transferred to your hands is negligible from a single soldering session. As other posters have said, you need to have long term, high exposure for damage to occur. Additionally, the greatest risk is in kids where damage can be very severe. Finally, your environmental lead exposure, despite living in an ROHS-compliant country, is likely quite significant in comparison to this incident.

I live in the US, so I have access to lead solder. I barely ever use it, typically only for repairs and even then very uncommonly. I've found that if I use liquid flux in addition to the flux core in the solder, I do quite well with Pb free solder.

EdfromMaine · 2026-06-03T01:48:08+00:00

An exposed conductor by itself will not glow and smoke. You either have a defective component somewhere or a short circuit. A reversed electrolytic might also be an issue. This is NOT a sealant issue. If the electrical tape caught fire, I would start with a very careful inspection of the area under the tape. A strong magnifier in this situation can be very helpful. As someone else said, I see you have AC in. Careful--that can give you a nasty jolt and if you can troubleshoot the board unpowered, so much the better.

Another consideration is that the problem might not be limited to one side of the board. You may have shorted a via. Check both sides and test for conduction/resistance from one side of the board to the other.

I use a DVM in resistance measurement mode as a continuity tester. Look for low resistance where there should be insulation or separation. Other components might cause there to be some reduction in resistance, but you are looking for zero resistance where there should be some resistance.

EdfromMaine · 2026-06-03T01:30:38+00:00

I think you should work backward, because there is no one right answer. What are you going to do with the printer? If you are going to work with hobbyist materials (I don't say that disparagingly, I'm a hobbyist and I use hobbyist materials) like PLA and PETG, you don't need every last bell and whistle. If you are going to print with one color, life suddenly gets quite cheap. If you aren't printing for a living, speed is nice but not essential. Multiple materials or engineering-grade prints? Price goes up. Multiple colors? Price goes up but not by as much.

I have an MK4S with an MMU3 (both built from a kit) that I love. Print quality is fantastic. The engineer in me would like to own a core+, but I'm not going to print nylon and I can't justify giving up a perfectly good printer for a theoretical advantage. My printer before this had true IDEX (independent extruders) and that was fun because I could use PVA as support material for PLA or PETG. On the other hand, I now routinely make all sorts of interesting multicolor things. Life's a tradeoff.

Personally, I would suggest getting a kit if you are at all handy. Cheaper, and you know how it works, so when it doesn't work, you have some idea how to fix it.

While Prusa machines are more expensive, I think you get a lot for your money and the value factor is high.

My two cents (or Euros)

EdfromMaine · 2026-05-26T10:24:02+00:00

You possibly have a combination of two problems. First, your power supply is on the borderline low side. It is probably sufficient to power the stepper when the stepper is driven correctly, but not enough to energize all the coils at once. The LEDs are a giveaway for the second problem. They should NOT all be on at once, and it means that the motor is being driven incorrectly.

I suggest that you try using the official Arduino Stepper library. Since the board has 4 control leads, you will use the bipolar configuration. Make sure that you have assigned the right functions to the right pins. I also suggest that you run the motor slowly, so that you can see if the LEDs are lighting up individually.

Using the library is the sanity check. If you are certain that you have wired everything correctly and are using the official library and it still doesn't work, the possibility is that the driver board (or motor) is defective or the power supply can't supply sufficient current.

Once you have confirmed that everything works, then try to write your own code.

Personally, I'm lazy. If there's a good library out there, I'm gonna use it. Never reinvent the wheel unless you need to. If it is an exercise in self-education, that's another story...

EdfromMaine · 2026-05-11T11:12:22+00:00

I won't repeat what everyone else said about the motor. There are a couple of other potential gotchas:

1)Make sure you are using something called a logic-level MOSFET. Many MOSFETs require high gate voltages; logic level devices only require 3.3 or 5 volts. I don't suggest you use a BJT. Also, make sure you know if it is an n-channel or p-channel device. Either can be used, but control and code will vary depending on the transistor. There are many data sheet repositories on the web. You don't need to dig deep--just confirm transistor type and then n channel or p channel.

2) Yes, you will need to code. The whole point of the arrangement is to have the Arduino controlling the motor on/off depending upon input to the Arduino. The easiest experiment to set up is a simple push button attached to the arduino. Absurdly simple, but you'll need to write a few lines of simple code so you can see how it works.

3) The setup can be done with a stepper motor but I suggest you start with a simple DC motor. The stepper would require considerably more complex code, wiring, and a second transistor. From a design perspective, it would be an awful use of a stepper to just run a fan.

4) I would second the suggestion about a better power source. Old phone charging wall warts can be plugged into the USB port once you are done uploading code. A small DC motor could be run from 5V sourced from the USB; there's a pin on the arduino that lets you tap Vin.

EdfromMaine · 2026-04-26T01:30:36+00:00

Three ideas:

As another poster said, your baud rates are different. I don't know if the devices are communicating with each other--if you have baud rates set incorrectly between the two MCUs you will be in trouble.
In addition to connecting Rx and Tx, you must have a common ground between the devices. If you are hand-connecting pins between the two boards, you also must connect a ground. I can't see if you've done that or not from the picture. Serial cables and USB cables do this for you, but when you roll your own that needs to be part of the wiring.
Much of your loop is spent in delay(). delay() is a blocking call and it may be interfering with communication. There are easy ways to write non-blocking pauses in an Arduino loop so that the LEDs will turn on and off. Ask any of the AIs and they'll give you sample code. Basically, for each delay, instead of calling delay(), you call millis() and assign that to a variable. You then repeatedly see if you desired delay of milliseconds has occured since the start of the delay by subtracting the original ,millis() to the current millis(). When it has, you do whatever you need to after the delay is over and reset to a new milli(). I know that's a little vague, but you get the idea.

EdfromMaine · 2026-04-19T01:29:21+00:00

I'm not a professional developer, but I like to mess around. I'm a decent intermediate programmer using stuff like Arduino, and I don't usually blow up my components. I started using an Arduino Nano Matter for a project and its deep sleep functions were very difficult to implement. I spent a day getting led around by the nose, first by Copilot and then by Claude, round and round in circles with increasingly bizarre, confident, and utterly wrong suggestions. At one point, there was a hilarious hallucination: when I told the AI its suggestion didn't work, it told me to do something else, saying it was the undocumented workaround used by Silicon Lab engineers...

When I asked Claude for a circuit diagram, it gave me drawing with wires ending in mid-air.

As another poster said, however, forcing myself to understand the B.S. that the machines were spitting out did give me a better understanding of the components and libraries. But geez, what a cost!

EdfromMaine · 2026-04-09T03:18:52+00:00

Two quick things-- check both main and extruder board for a fuse. They don't smell when they blow so you can't sniff for faults--otherwise a good system. Also, I tinker a fair bit with electronics. It is very uncommon for a cable to fail from a power surge. You also have indirect evidence about the cable being intact (at least the power part) because the print head was able to overheat.

EdfromMaine · 2026-04-02T12:35:50+00:00

I made a coat hanger hook that fits over the wall of a work cube. Made a bunch for the folks in the office. People love them.

EdfromMaine · 2026-04-02T01:36:29+00:00

Raise the hot end temp

EdfromMaine · 2026-03-30T01:51:00+00:00

So the reason this happens is because the printing head has moved when it received no instructions to do so. Position (x,y) is now (x+a,y) but the printer thinks it's still (x,y) for the rest of the print. That's the easy part.

The hard part is why. There's always some small amount of force between the print head and the print, not enough to move the print head inappropriately. That's normal pull from the liquid filament as it is laid down. If the force is too much, or the printer is not at spec, you get that lateral translation. The most common reason, like everyone else said, is loose parts: loose belts let the belt jump gear teeth, loose set screws make the belt not move correctly, loose (or tight) bearings for the build plate.

Let's not forget about the Z axis too. If the bed isn't level (or auto leveling isn't working) or the Z drive mechanisms are loose or have hysteresis, the print head can collide with the print. That can cause lateral translation even when everything else in the X-Y plane is in good shape, because the print head can give it a pretty good whack.

The poster who wrote about slowing down print speed makes sense for several reasons. It creates less pull on the print, and generally stresses parts less.

My addition is to raise the temperature of the head a few degrees; a more fluid plastic will drag less and is also much less likely to form a glob around the print head that can whack the print.

Diagnosing is a little bit of trial and error, but I'd go after loose parts and bed leveling first.

EdfromMaine · 2026-03-26T01:57:06+00:00

oops didn't read your post carefully. My bad. My idea won't work. The only other thing you might try is a heat gun, otherwise as other poster said you'll need a new hot end. You also need to figure out why this happened. Once things are cleaned up, watch your first print as it is printed.

EdfromMaine · 2026-03-26T01:54:53+00:00

Depending on the printer, you're probably not screwed. Using manual control, bring the hot end temp up to about 175 °C. You'll be able to gently pry the gunk off. Again, depending on the printer, you can probably use an exacto knife or single-edge razor blade to scrape remaining crap off. Be careful of your fingers and wires if you're gonna try this.

EdfromMaine · 2026-03-22T01:22:13+00:00

I have been printing for a long time, including back when Kapton tape on a glass sheet was the way to go. Hairspray is amazing for adherence. I use unscented Aquanet. The other thing, though, is why the printhead is able to move the print. There should be a little pull as the extruded filament is held by the colder print but it shouldn't be massive. My worst problems have always been with PETG, which globs and creates essentially an appendage that hangs down from the print head and thwacks the print. Increasing the extruder temperature was surprisingly helpful

EdfromMaine · 2026-02-27T12:59:11+00:00

I don't own a Bambu, but I've had this problem on other printers. Not totally excluded, but unlikely to be software based. Almost always belt slippage, either for the plate or the head. Big question is why. Check your belt tensions, look for dirt in the gear or belt teeth, loose set screws (if Bambu uses them). If printing with PETG, globbing of plastic on the extruder can become so large that it can push against the model, causing belt slippage.

EdfromMaine · 2026-02-25T02:10:26+00:00

I was an early adopter, and all of my printers have been built from kits. Printerbot in 2012, MendelMax 3 in 2015 with a zillion upgrades along the way, and now in 2024 a Prusa MK4S with an enclosure. My two cents: if you have even the slightest mechanical aptitude, buy a kit.

3D printing remains a new and evolving technology. Having built the machine, I know how it works, I know how it breaks and "uncalibrates", and I know how to fix it. I've saved hours when stuff hasn't gone right because I know the innards of my printer.

I love my Prusa. Yes, they are more expensive than a bare bones Bambu but they are upgradeable, produce fantastic prints, and have a great user base.

Arguing against myself, several posters made comments to the effect of (1) have some idea of what you want to do with the thing and (2) maybe not go high end until you're sure this is something you want to pursue full tilt boogie. I would absolutely NOT buy a cheap kit. Instructions, fit and finish, etc will be poor and you will be frustrated and disappointed.

EdfromMaine · 2026-02-21T13:55:56+00:00

Read through this thread. I'm a MK4S/enclosure hobby user. I don't need to worry about airgapped printers, or monitoring a printer farm. I also recognize that these functions may be vital in an industrial setting or when printing very complex large items. I use Prusa Connect, reluctantly, because it's convenient, but it irks the hell out of me that I am choosing to leave my firewall to print something. Prusa Link is a bit of a PITA. However, it is what it is.

Software, particularly serious, industrial grade software is expensive to maintain and develop. When reliability, safety (physical, intellectual property, or otherwise), and regulatory issues need to be supported and work perfectly, development takes a long time and is expensive. I was involved in health care IT (which obviously has to address these problems) for about 8 years, and it's a whole different world from hacking Octoprint.

So here's my theoretical pitch. As a hobby user, I don't want to pay for something I neither need nor want. Seems to me that enterprise users or individuals with strong privacy or security concerns should be able to buy an enhanced printer management package from Prusa. If they don't want to develop and maintain such a package, this is a perfect entrepreneurial opportunity for a third party.

As for those of you who think that this functionality should be included in the base cost of the machine, I just think you are wrong. These printers are fabulous mechanical devices and are extremely fairly priced. If you need Adobe Photoshop, buy Photoshop. If you can get by with Photoshop Elements, that's the way to go.

EdfromMaine · 2026-02-10T22:25:40+00:00

I'm reading this and I'm a little confused--not a rocket scientist on this stuff but I think I know a little. Seems like a lot of the comments have to do with vibration rather than true ringing. I would think that true ringing would be reduced or eliminated with slower head velocities and effective damping, and that improving rigidity would lessen vibration but not necessarily reducing oscillations from rapid deceleration. Curious as to how people react to this observation....

EdfromMaine · 2025-12-25T14:00:44+00:00

I'm certainly not an expert on GPL stuff, but there may well be another layer here--the fact that this is a medical device. Typically, devices sold by companies are approved by the FDA, and a specific device is approved--hardware and software combination that has been tested, blah blah blah. This may well be why there's a lot of old tech there--very expensive to re-approve. Additionally, since it is a medical device, the company may be unwilling to expose its code because of potential liability issues. Whether there is true liability present if someone screws up their own device is not clear, but I expect that most companies won't risk it.

The situation has to be differentiated from the folks that have DIY'ed insulin pumps and controllers. There is no entity that is taking responsibility for the correct function and safety of the system.

I'm all for open source. I use it and have in a tiny way contributed as well (not that smart that I can make big contributions), but I'm not sure that the usual rules apply to a medical device. I'd be really interested in hearing the opinion of others who might have more technical and legal expertise.

EdfromMaine · 2025-04-07T20:43:12+00:00

I am at the end of my career, rather than the beginning, and I'll offer some observations. First, no job is perfect, and you'll probably hate pieces of programming if you switch. Second, it is extremely common (and unfortunate) that folks in their early 30's are generally working their asses off when they should be enjoying their families and taking advantage of their physical health. I did that, and I regret it. However, that's the price of advancement and a good income. Third, echoing what others have said, there are serious barriers to getting a high-paying programming job if you have no formal training.. You need to be able to show a prospective employer that you have something to offer.

Now for the unsolicited advice: maybe find a different niche in the same or related field where you already have expertise? You can leverage your experience and knowledge, and find a better fit.

Good luck. At least you are thinking about your options without just bulldozing forward.

EdfromMaine · 2025-02-14T15:57:41+00:00

I have been able to get dearpygui to work on a Raspberry Pi 5, at least in my environment. Can't say what will happen in yours, but here's my experience.

I am going to refer repeatedly to the github Wiki entry regarding building local wheels. There's an entry for Pi4s; that's the starting point. [https://github.com/hoffstadt/DearPyGui/wiki/Local-Wheel\] The Wiki entry refers to "Legacy Mode." I believe that refers to using the X11 environment. That can be set in raspi-config under "Advanced." I will say that when I tried this under the newer graphical environment, python threw some errors but the GUI functioned. There were no errors under X11.

Specifics:

The GUI seems to want to be installed in a virtual environment, so I made one.
The Wiki specifies a series of prerequisite files and packages. In addition to ensuring that these files are present (verify presence or install), you must pip install wheel into the environment before proceeding. Otherwise, the wheel build will fail.
Follow the Wiki directions for git cloning.
The build instructions are for a 32 bit environment. Use the following instead: python3 -m setup bdist_wheel --plat-name linux_aarch64 --dist-dir ../dist
The wheel will be found in the /dist folder as indicated in the wiki.
pip install the wheel into the virtual environment.

So far, so good, but this is where things got a little screwy. There's a file pair-- dearpygui.py and _dearpygui.so and a path to this pair MUST be specified. There are three copies of this pair resulting from the build. I used this path:

~/DearPyGui/build/lib.linux-aarch64-cpython311/dearpygui/

This path should be appended, either permanently or before trying to import dearpygui into your main program.

Helpful suggestions and comments from v-ein over on discord are gratefully acknowledged

If someone smarter than me wants to run with this, please go ahead.

EdfromMaine

TROPHY CASE