Arduino Usb Adapter

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Enrique Fats

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Aug 3, 2024, 5:53:40 PM8/3/24

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Before i destroy my Arduino UNO by connecting it to this adapter, i would like to ask if this adapter is safe to be used with my UNO? It connects to the mains and it outputs 12 V DC but it also says 2 A, which is what i'm worried about. Isn't that way above the current limit for the Arduino?

A very real danger is that the thoroughly obsolete tutorials on the Arduino site (written ten or more years ago and simply not updated) and others misleadingly imply that the largely ornamental "barrel jack" and "Vin" connections to the on-board regulator allow a usable source of 5 V power.

This is absolutely not the case. It is essentially only for demonstration use of the bare board back in the very beginning of the Arduino project - "back in the days" - when "9V" transformer-rectifier-capacitor power packs were common and this was a practical way to power a lone Arduino board for initial demonstration purposes. And even then it was limited because an unloaded 9 V transformer-rectifier-capacitor supply would generally provide over 12 V which the regulator could barely handle.

This is because the on-board regulator is essentially capable of powering only the microcontroller itself and no more than a couple of indicator LEDs. The on-board regulator might be able to power a few other things if it had a heatsink, but on the Arduinos, it does not.

Powering via the "barrel jack" or "Vin" connections is asking for trouble. The "5V" pin is not by any means an output pin, if anything a "reference" pin but most certainly the preferred pin to which to supply a regulated 5 V.

I have the same power supply in the OP's photo that had been powering an Uno (through the 2.1mm power jack) with a Music Shield and a Wemos D1 Mini (from the Uno 5V pin) for months, often 24/7, (my project is taking forever) and the regulator on the Uno is barely warm.

It is more related to the experience of those of us who answer here to the interminable dribble of posts asking "Why when I added this piece to my Arduino did it suddenly stop working after so-and-so length of time".

I would also opine that Paul__B's assessment of the on-board regulator is excessively pessimistic, but the basic point is there - the regulator can't provide all that much current. Couple hundred mA is all it can be relied upon for. For anything more than that, you need an external 5v supply.

As stated before, I am powering an Uno with the same wall-wart as the OP. The Uno 5V pin is powering a Wemos D1 Mini. And there is an audio shield on the Uno. It's been running almost 27/7 for three months and the chips on the Uno are barely warm.

Using an IR thermometer, the Atmel processor is the hottest chip on the Uno, at 87.5(F). The regulator is slightly cooler at 87.2(f). The ambient temperature in the room is about 79(F), so statements to the contrary above don't appear to present in my project.

The MKR2UNO Adapter allows you to turn your Arduino UNO form factor based project into a MKR based one without too much effort! You can so upgrade your project with a powerful board with integrated LiPo battery charger.

Please keep in mind that the MKR2UNO is just a form factor adapter and so is NOT present any voltage translation. Be careful before connecting a shield since shield without IOREF level shifting capability may not work properly.

I am working on a project where an Arduino UNO reads the time from a DS3231 and controls a relay FL-3FF-S-Z. The relay would be powered for a maximum of 5 mins per day. Would a 9V 1A adapter ( -1a-dc-power-adapter/) work for 2 weeks via DC jack without burning or seriously damaging the Arduino UNO ?

Due to the limitations of the on-board regulator, powering from other than 5 V is a generally bad idea.. One relay (on a module of course, with its control transistor) drawing a nominal 90 mA when actuated you may get away with at 9 V, but the risk is that at some stage you will add something else drawing current and wonder why it becomes unreliable.

Be careful with phone chargers. They are for charging. Some cheap chargers with an 5V output has actually 6-6.5V at low current consumption. If you apply such a voltage to Arduino, it will be bad for him.

So how would I suuply the 5V if a 9V adapter is too much and a 5V adapter might provide higher voltage at low current levels? Is it impossible to use an arduino powered from anything apart from a USB port on a computer or a laptop?

You need 5 V. "Boffin" has spooked you to start with but corrected himself. Just check the voltage with your multimeter in case it is some piece of rubbish. A branded device such as Apple or Samsung should be the real deal or one you buy in a local shop. Ridiculously cheap ones direct from China may not only be poorly regulated, but unsafe.

I think responders are mixing metaphors.
If you supply +5V through the 5V pin, then the 5V has to be well-regulated, clean and capable of at least 1 Amp. Most phone chargers don't provide a well-regulated 5V or 1 Amp.
If you provide 7V to 12V to the barrel jack, you are OK. Anything less won't work because the 5V regulator on the PCB won't regulate to 5V. 7 to 9V is best. If you power ONLY the Arduino with 12V through the barrel jack, you will not likely ever have an issue. I have powered Uno projects using a 12V wall-wart for weeks at a time and never an issue. (Yes, the on-board regulator gets warm. Not hot). If you power downstream peripherals such as LED strings, relays or motors through the 5V pin, then you are probably out of spec and risk smoking the on-board regulator.

Is you connected you 5V 4A to your Arduino, and you wanted to control a 500ma motor (using a relay or some driver) you cannot connect the 500ma motor to any of the 5V pins on the board, it must be connected directly to the 5V 4A supply.

This is one of my pet peeve's. Real cheap ac adapters from China rarely meet the stated output requirements. The sellers count on the fact that most users buying supplies on ebay will never draw more that 50% of the rated current. You can google ac adapter teardown and find many sites showing the poor build quality of these adapters.

And the worst issue with cheap AC adapters. If they are not UL approved** the isolation between mains voltage and the DC output is woefully inadequate. This means that if the adapter is dropped one too many times or allowed to get too hot too many times, one of the input pins could become connected to the output. Not a good situation.

I have made a home automation Arduino project using an HC-05 Bluetooth module. I want to power my Arduino from the main AC supply. Can I use a mobile charger/adapter to power it? Or should I buy a 12v adapter, and solder it to a barrel connector that fits the Arduino input?

Try to stay away from the QC2.0 or QC3.0. they are intelligent and negotiate the output voltage on the phone, up to 9 or 12v. They are compatible with non smart load but you don't want to run the risk.

I am in the middle of this problem now and it seems the two out of three chargers I tried attempt to negotiate the voltage with my Arduino system. Those are Huawei and Meizu ones designed to be used with multiple devices of their respective brands. The multimeter reads solid 5.2V output before I flip the switch to Arduinos. Once I flip the switch the multimeter starts jumping hectically from 1.8 to 2.6v and all the LEDs on Arduinos and other components start flashing like a Christmas tree. Browning out, I assume. The adapter that works is a really cheap nameless one that I got for free in some package.

Plugging Arduinos into the battery bank and the charger into that battery bank seems to be a very stable and versatile solution that hasn't created any problems for me yet. Except that most battery banks have trouble producing over 2 amperes of current if your system needs that much.

In a lot of situations, it would be useful to have a Y-shaped jumper wire to split signals. For example, many variants of the Arduino Uno have only a single 5V pin. Unfortunately, most breakout boards require to connect their GND and 5V pins to the Arduino. If you do not use a breadboard, this can become very annoying due to the very limited amount of only a single 5V pin. Moreover, if you want to share a signal with an Arduino Uno and an oscilloscope, a Y-adapter for your pin could come in handy, too.

When I was looking for such Y-shaped jumper wires on shopping portals, I was a bit surprised that I could barely find any offer. Therefore, I decided to make my own Y-shaped jumper wire. If you are new with crimping connectors, it makes sense to have a look at my previous crimping tutorial.

Has anyone here encountered a similar issue or has any insights on what might be going wrong? Any advice on troubleshooting steps, configuration adjustments, or alternative approaches to establish a successful connection between my Arduino and Micro-Manager would be greatly appreciated. I currently am attempting to create my own configuration file without having to rely on the Hardware Configuration Wizard as a last resort.

Thanks for the reply! I actually initially attempted to upload the firmware you mentioned, however ran into a compilation error in the Arduino IDE and could not successfully upload it. By any chance, could this firmware be outdated?

Your UNO R4 has a very different processor from the previous versions of the Arduino, i.e. a 32 bit ARM Cortex-M4. Luckily, Bonno Meddens has written firmware for these types of boards. Look at: Arduino32bitBoards.

It sounds like you are trying to upload the source code for the Arduino Device adapter. That will not work. The firmware for the Arduino 32bit boards can be found here: Arduino32BitBoards/Firmwares at master bonnom/Arduino32BitBoards GitHub