33
votes
How to identify Arduino Mini Pro 5v vs 3.3v
Consideration (go down for the actual solution)
If you have a lot of different China-Arduino-clones, the easiest way will be to just test it. The cloned Arduinos use a lot of different voltage ...
- 431
15
votes
Accepted
Does ADC conversion to a voltage rely on the actual value of the +5 V pin?
The ADC inside the Arduino does not measure voltage, but rather a
voltage ratio. Namely the ratio from the voltage at the analog input
to the voltage at the Vref pin.
In the default configuration, ...
- 42.2k
13
votes
Accepted
How to output a true analog voltage at output pin
You basically have three options:
Switch to an Arduino Due which has a built-in DAC which outputs a real voltage.
Add an external DAC chip (such as the MCP4821/2) to create the voltage for you
Use a ...
- 105k
12
votes
Accepted
Two batteries sharing ground?
Not only can you share the grounds - sharing the grounds is required for there to be any form of meaningful circuit for signals to get around the place.
To copy-and-paste a blog post I wrote some time ...
- 105k
9
votes
Accepted
Powering Arduino Uno from 5V pin, what exactly is the voltage range/tolerance?
Unfortunately there is no one "clear cut" answer for all you ask.
There are some hard limits, though, which you can get from the main chip's datasheet:
Operating Voltage: 1.8 - 5.5V
But that's ...
- 105k
9
votes
Does ADC conversion to a voltage rely on the actual value of the +5 V pin?
A USB-powered Arduino Nano will have an ADC voltage reference which can't be relied on, due to the +/- 5% tolerance of the incoming USB voltage. On top of that, the Nano has an MBR0520 Schottky diode (...
- 2,114
7
votes
How to identify Arduino Mini Pro 5v vs 3.3v
The safe way (i tested it).
First connect to 3.3V USB-TTL output first (also 5V Mini can work with 3.3V).
Now prepare this sketch:
void setup() {
pinMode(13, OUTPUT);
}
void loop() {
...
- 71
7
votes
Accepted
When it says the Uno has logic level at 5 V is that also true of a bareduino/breadboard Arduino?
The logic level is the same as the voltage you supply the chip.
You can think of the IO pins as tiny switches that either connect the output pin to the supply voltage or to ground (when in output ...
- 105k
7
votes
Accepted
Precision voltmeter using Arduino
A divider is used to (as the name suggests) reduce a higher voltage to a lower voltage. Using a divider on a small voltage will only make it smaller and harder to measure.
To get the most out of ...
- 105k
7
votes
Accepted
Do I use 3,3V or 5V, when device supports both?
Using the MAX3232 data sheet , which is what the TTL Converter has on it's board :
The main difference between using 3.3v or 5v is on the receiver data line "R" (or Rout as it is called on the ...
- 600
7
votes
How to output a true analog voltage at output pin
At 5V, a 1 ohm resistor will try to sink 1A and far exceed the 40mA specs. Please use at least a 5/0.040=125 ohm resistor to protect your pin. And if you put the a capacitor between your resistor ...
- 2,332
7
votes
Accepted
Getting 3.3v on 5v pin in Arduino Uno
and an external 5V DC power supply
OK, assuming you are putting 5V into the barrel jack this is exactly what you expect to happen.
From the Arduino Uno specifications you are supposed to supply a ...
- 37.9k
7
votes
Accepted
How can I create a battery level circuit
Firstly, if I understand your schematic right, you're not "dividing" anything there. If the ringed red symbol is where you are connecting the ADC then either you will see near 4V on there (if it's ...
- 105k
6
votes
Accepted
How to power my Arduino mini using wall socket?
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 ...
- 2,114
6
votes
Logic level converter not working?
Based on your schematic, you need to provide a 3.3v power source to the 3.3v side of the logic level converter. You can use the 3.3v pin on the Arduino.
Also, it's really hard to evaluate your ...
- 1,149
6
votes
How to measure the supply voltage of Arduino without using an analog pin
Yes, you can do it.
You can measure the voltage of the internal (approximately) 1.1V reference voltage using the ADC and use the results of that to calculate what the reference voltage you used (VCC) ...
- 105k
5
votes
What are the 5V and VIN pins for?
5V pin can be used to power up shields like Bluetooth, RFID, ultrasonic sensors etc..
vin pin is used to power up the Arduino. For example, when using shields such as L298 motor shield which is ...
5
votes
WiFi module ESP8266 + Arduino Uno
Since all of the data pins use 5 V, one of the solutions is to use a voltage regulator, such as LM2596.
You do not want a voltage regulator you need a level shifter.
You can buy them cheaply or make ...
- 37.9k
5
votes
Safely enabling voltage divider on a 12V battery
I use a similar system on a product I recently worked on to monitor the battery voltage - and of course I didn't want it on all the time to drain the battery.
The trick, though, is to do the exact ...
- 105k
5
votes
Accepted
Where is the Aref pin for Attitny88
As shown in the detailed information for the ADMUX register in the ADC section of the datasheet, the ATtiny88 has no external voltage reference. Consider using a ATmega8 or ATmega88PB instead.
- 17.6k
5
votes
Accepted
How do I turn off a 12V 3A RGB LED strip?
That's pretty simple: when you turn off all the colours you are actually turning off the entire strip with very minimum leakage current in each of the three FETs.
- 1,281
5
votes
Accepted
WS2812 - First are white and then they turn red/yellow/orange near the end
See Powering NeoPixels.
Each individual NeoPixel draws up to 60 milliamps at maximum brightness white (red + green + blue).
...
To estimate power supply needs, multiply the number of ...
- 37.9k
5
votes
Accepted
This logic level converter does not want to work
The TSX0108 doesn't magically provide you with a regulated voltage. You have to provide the voltage, the TSX0108 merely switches it.
As you can see from the datasheet, the basic wiring is:
In the ...
- 105k
5
votes
Accepted
Does the Arduino Yun have to be powered exactly at 5V?
It is fine. That is only 2% too high. The microcontroller is the ATmega32U4 and it can have 5.5V. The wifi module runs at 3.3V, and it has a voltage regulator. Some voltage is also lost in the cable. ...
- 3,216
5
votes
The need to use logic level converter
Level logic converting for level shifting is different from powering a device.
Logic level is the state of a digital input/output. No voltage (or very little of it) is considered LOW. Over the ...
- 17.7k
5
votes
Accepted
Digital I/O threshold voltages for ATmega32u4
LVTTL is Low Voltage Transistor-Transistor Logic. In general, the
term "TTL" is used for a digital signal.
The "Low Voltage" part is special,
the ATmega32U4 switches from low to high (and vice versa) ...
- 3,216
5
votes
Accepted
Output voltage range between 0-5v
Short answer: No.
Arduino Unos and Megas have PWM (Pulse Width Modulation) output, which rapidly turn the output on and off with a varying "duty cycle" (The ratio of on time to off time.) ...
- 5,642
4
votes
Safely enabling voltage divider on a 12V battery
I'd use some very large resistors (e.g. 1 and 2 Mega Ohm), and add a small capacitor to the center, to stabilize the value during sampling. Using 1 and 2 MOhm would result in 10uA of current loss, ...
- 11.3k
4
votes
Generating digital positive (+5 V) and negative (-5 V) signal?
It is not so easy to create a -5v power supply using a capacitor or transistor.
A very easy way is to use an additional Wall wart power supply to create -5 volts (while still using your original +5 ...
- 600
4
votes
How to reduce current from a AC TO DC power supply for arduino use
You don't need to reduce the current.
2000MA (2 amps) means the power supply is CAPABLE of supplying this (without overheating). Anything less than this, and your device will work perfectly.
Your ...
- 2,373
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