18

The genuine Pro Mini's use a MIC5205 regulator which should accept up to 16V at it's input normally, with an absolute maximum of 20V. It's unlikely that the regulator would be damaged by 15.1V. However, the component you have indicated that has blown is a capacitor. SMD capacitors are available in different voltage ratings, typically 4V, 6.3V, 10V, 16V, 25V,...


15

I made up a small torch locator which used an ATtiny85 powered from a button-cell (CR2032). It looks like this: Other side: That currently weighs 5.9g. The battery-holder weighs 1.6g so you could save that by making a more light-weight holder (perhaps a bit of plastic for insulation, and soldering directly to the battery). The chip socket weighs at least 0....


11

There are three things you can do: Remove the bootloader entirely and program the board with a hardware programmer (USB-ASP, Another Arduino, etc). Edit the bootloader source, recompile, and reinstall it to the board using a hardware programmer (as in option 1). Just don't use pin 13 for the relay. Of the three options the third one is by far the simplest.


10

Nowadays, most smartphones come with a charger that is linked to the USB plug of the phone. The charger for my HTC says: 5V, 1A, I guess this voltage must be regulated (but I haven't checked it has the charger is sealed). The charger itself has a female USB socket on which you can plug any USB cord to link to your Arduino. IMPORTANT! I have never tried it ...


10

I can suggest you to try this : AC DC Step Down Converter It is as small as the Apple's tiny cube, and it can be placed inside of a wall easily. (I'm personally using this with an arduino micro)


10

It is more the differences between ATMega328P + FTDI (Pro Mini) vs ATMega32u4 (Pro Micro) Apart from the minor pin differences, the peripherals for both MCUs are the same. The major difference is the ATMega32u4 has built in full-speed USB. This allows the board to function as a USB device by implementing the appropriate USB stack. E.g. it can act as a USB ...


9

I have good news, and I have bad news. The good news is that only two changes to the board are required to change it from a 5V board to a 3.3V (or any voltage within spec) board. The bad news is that there's no way in hell you'll be able to do them. So, we work around them and get the board up and running. The first is obvious: a 3.3V board should be ...


8

Call serial.end() to stop receiving. Then call serial.begin(...) again when you want to start listening again.


8

I would personnaly suggest an ATtiny 45/85. It is pretty much a small AVR with 5 GPIOs. You can program it with the Arduino IDE and use the Arduino as ISP. If you can design you own custom PCB, a SMD version of the ATtiny is small, low and compact. The total circuit to make the ATtiny function is also minimal. Also, at a low clock speed (0-4MHz), you can ...


7

After poking around for a bit more, it turns out my problem was the baud rate. I could make it work by setting it to 19200, just a little slower. Alternatively, you can modify the ArduinoISP sketch to enable higher baud rates. I used this post to enable 115200 baud and I was able to successfully use avrdude at the higher rates. Not sure how I missed this ...


7

Can I use a I/O as (input/supply) GND? You can use an I/O pin as a supply for another (low power) device, but you should power the Arduino itself from its Vcc and GND pins. I could use the reset button, but would it still give me "random enough" numbers? You will likely see the very same sequence every time you reset it. There are ways around this: ...


6

The last resort option is to open a 5v phone charger and replace the metal prongs that go in a socket with two wires, and replace the usb socket with another pair of wires that go the arduino board, but still, an Arduino Pro Mini or an Arduino Nano is smaller than the phone charger. You will probably have to do something like that. Because of the nature of ...


6

It's hard to tell from your pictures, but are all the header pins soldered to the boards? If not, they need to be: there's no chance that the proper electrical connections will be made reliably if they're just inserted loosely into the holes.


6

This is what I have managed to achieve ... Library IRLib - GitHub Version 1.51 March 2015 Copyright 2013-2015 by Chris Young http://tech.cyborg5.com/irlib/ This library is a major rewrite of IRemote by Ken Shirriff which was covered by GNU LESSER GENERAL PUBLIC LICENSE ... Code Modified code (from the demo IRrecord example): /* Example ...


6

The only thing about the 3.3V Pro Mini that is actually 3.3V is the 3.3V regulator. The main chip (pretty much the only other component) is good for anything from 1.8V up to 5.5V. Running direct from a 3.7V LiPo or Li-Ion will be perfectly fine. You might want to disconnect or otherwise disable the regulator though to reduce current consumption - the ...


6

Most USB to serial chips set the DTR to LOW on connecting, but it keeps it LOW. This would reset the arduino, but since the DTR never goes HIGH the Arduino will never get out of this reset state, and not run your code. The capacitor will AC couple the signal. The the DTR goes low, the other side of the capacitor will go LOW too, but the pull-up resistor ...


6

Officially, no. Practically, often but not always. If I follow the datasheet to the the letter, this configuration should not work. BUT... After some test, it did work. The data sheet does not say that it "should not" work, it says that it is that the part is not qualified for operation at 16 MHz below some voltage higher than you want to use. That ...


6

I have connected the Relay and IR receiver directly to the Arduino mini. Pin 10-14 are used for the relays Ins and PWD 3 for IR output. I hope you don't mean that you have connected the coils of the relays directly to the Arduino pins. If that's the case, the surprise won't be the regulator blowing up, but the MCU surviving. Please edit the post and add ...


5

This is part of a Fritzing circuit I used to control the x'mas tree lights (the relays and sensors have been snipped out) with an XBee. This circuit uses a 3.3v LDO you may have to change the capacitor values depending on your regulator specs. I chose to use a separate 5V regulator (not shown) but it will work off the Pro Mini's +5V power rail. There are ...


5

This error means that the program responsible for uploading (avrdude) can not communicate with your arduino. Did you reset the board just before programming? The reset pin of the arduino seems unconnected in your picture; so the board wouldn't be executing the bootloader when the serial cables expects it to. Try either to reset the board manually just ...


5

Bootloader of the Mini and Uno are pretty much the same. (I can't find the source-code but the hex files are only slightly different). The 2k is because they haven't updated mini328.upload.maximum_size in boards.txt. Probably because that would break the board for users that haven't updated the bootloader yet. The 2560 is using a stk500v2 compatible boot ...


5

To generate a square wave, you only need to update the output at a rate of two points per cycle. (Technically, when the Arduino's PWM output is configured for 50% duty cycle, that's a square wave at some frequency.) But to generate a clean sine wave (without a lot of distortion), you need to update a lot more frequenclly than two points per cycle. ...


5

rx -> tx tx -> rx Please check your connections.


4

The smallest is probably a plug-in USB charger such as Apple's tiny cube. The cheapest is bound to be a ~9v (output) wall-wart scrounged from the lost and found in a tourist's/traveller's hotel.


4

wanted to do a similar thing and I found and just ordered these: http://uk.farnell.com/recom-power/rac03-05scr-277/conv-ac-dc-3w-90-305v-in-5v-out/dp/2289701 A fully sealed power supply, disk-shaped, 5cm diameter and 11mm thick. THey are available in 3.3V, 5V, and 12V. They are designed to be put inside walls or behind switches.


4

An obvious answer has been omitted which is: transformerless power supply. If your average power requirements are low (<10mA) then this is the most compact way to achieve the desired voltage. For an in-depth study see: http://ww1.microchip.com/downloads/en/AppNotes/00954A.pdf Another solution: jeelabs.org /2011/11/27/ultra-low-power-supply/ Some ...


4

One of the most obvious issues here is that you are enabling the watchdog timer with a delay of 1S and then you are asking the micro controller to sleep for 2S, printing something and then going back into the loop. This, in theory, should be fine(your wdt should trigger a reboot during the 2 second wait) but I've seen it cause issues. Additionally some ...


4

Arduino Pro Mini is programmed through serial, using a bootloader. It uses STK500 protocol, which is described by Atmel. In theory, it can be possible to program multiple boards if only one TX Arduino pin is connected to USB-Serial converter, and all RX are in parralel, but this is an unreliable method. Only the board with TX pin connected can send its ...


4

The device ID and every other stuff is working fine. The only issue being that my code gets stuck at Wire.endTransmission(). Nothing is transmitted until you call Wire.endTransmission() so that is where it will hang. You should not try to do Wire transmissions inside an ISR (if you are doing that). There is an alternative to the Wire library which times-out ...


4

See this nice article by Adafruit, which explains how to run an Arduino Uno at 16Mhz with 3.3v. Both the Arduino Pro Mini and the Uno use the same ATmega328p chip, and they claim that even though running at 16Mhz is out of specs, it should work. As Ignacio mentioned in his answer, there will be no alternative to downclocking the Mini Pro if you want to ...


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