The 6-12V range applies only to the onboard voltage regulator(if you provide power via Vin or the barrel jack). The Arduino itself runs on 5V and the regulator needs a bit headroom above that to do the regulation.
You can run the Arduino via USB, since it has 5V, just as needed by the Arduino
And you can provide power directly to the 5V pin (with a voltage ...
Using the 1.1V internal analog reference to measure a draining VCC
source by using a voltage divider on it
You could indeed use a voltage divider, and measure a scaled-down Vcc
against the internal 1.1 V reference. This is, however, not what
the code you posted is doing. It is instead measuring the internal
reference against Vcc, as stated in the comment ...
There is a basic error in your methodology which leads to incorrect conclusions.
You cannot determine what is going on from just two data points. Instead you need far more.
Here is a voltage sweep from 5V to 12V with a 0.05V resolution (overkill, but the default setting for the script I use) connected to a Mega:
As you can see the current steadily climes ...
It will not be possible for you to PWM dim your LED with that LED driver (power supply).
That is a constant current driver with under/over-voltage protection. It delivers a specific amount of current (1.5A) and varies the voltage to allow that to happen.
If the voltage rises too high or falls too low then there must be a fault, so it shuts the power off. ...
Well, if you put 5V into your barrel jack, your UNO's onboard 5V regulator is going to drop that down to 3.5V or so. You must have more than 5V into the regulator to get 5V out of it. This is referred to as the regulator's "drop out" voltage.
The specs for an UNO say to power it from at least 7V for that reason.
As an experiment you ...
If anyone else is confused by this:
Will it hurt your Arduino?
No, this is a internal voltage reference between VCC & the 1.1v internal analog reference.
Is a voltage divider necessary?
Not unless you have something external of the Arduino to measure!
Is the internal reference actually 1.1v?
No, it seems like each pro mini I have the the 1.1v ...
To keep the same brightness, you have to keep the same duty cycle (percent of on time over off time). So to change the rate without changing the brightness, you have to increase
delayMicroseconds(onTime) by the same percent you increase delay(strobeDelay). But note that as you go slower, the on time will be too long to freeze the motion you are trying to ...
It all depends on the external device. If it has high-impedance inputs,
then it makes no difference. The Arduino itself has high-impedance on
its pins configured as INPUT. If the device draws current from this
signal, then chances are it will draw more current from an OUTOUT
HIGH than from an INPUT_PULLUP. How much more? We cannot say without
knowing the ...
No,you cannot split the voltage and expect the devices (Arduino and LED strip) to work correctly together (would lead to different ground levels beside other problems). For getting a different voltage you would need a voltage regulator. A switching "buck" regulator is the better choice here than a linear regulator (lile the one on the Arduino), ...
On the nodeMCU board all the 3.3v pins have continuity. That means they all do the same thing. And yes, you can apply ~3.3v to them. I have trouble with voltages under ~2.8 though, 2.5v is likely not going to work.
Use a buck+boost to keep it 3.3v if needed. For cheap dc/dc converters, I strongly prefer ones with XL semi chips; clean enough to please the ...
I think the answer to your question can best be summed up by one word: "Kinda".
The best reasoning is the NodeMCU Lua documentation which states:
Time keeping on the ESP8266 is technically quite challenging. Despite being named RTC, the RTC is not really a Real Time Clock in the normal sense of the word. While it does keep a counter ticking while ...
As mentioned in the comments, you cannot power your robot from a 9V block battery. These are made for low power projects (like a smoke detector) and cannot provide enough current to drive even only the motors correctly. Using 2 of them does not really help much. You need to change to a different battery type. If you want to stay with alkalines, you could use ...
Motors draw a LOT of current compared to CMOS circuits.
The 3.3V output on most Arduinos can only provide a very small amount of current. The Arduino Uno, for example, says it only provides a max of 50mA from its 3.3V regulator. Your motor driver probably needs >10X more than that.
The overload protection on the Arduino's voltage regulator will probably ...
If you connect it from the USB port on your computer to the USB plug on the Mega, you'll do fine. What you can't do is connect a 5v source to the barrel jack; that goes to the board's voltage regulator which needs ~ 7v minimum to provide 5v out.
"Quite a bit of power" is a rather vague specification. A USB port can supply 500mA unless the device in ...
That is a perfectly legitimate use of the RESET pin. Holding the chip in reset perfectly valid. Everything in the chip will be stopped.
Releasing it will start your sketch from the start again perfectly fine.
The only negative point is that your switch will be pulling power through the reset pin's pullup resistor, so will waste a little power.
As soon as I connect up the battery, I loose the Serial Monitor connection (even though the USB cable is still connected). So I can no longer see what's going on inside the Arduino for debugging purposes. Why? How can I continue to see the Serial Monitor? Is there a way to see the serial output from somewhere other than the USB jack?
Probably because ...
I've seen people saying something about putting the grounds of the board and the module together
Yes, I believe this is what you need to do.
Servo is connected by to pin 10, and the ground and power are both routed through the 5V power module which is attached to a 9V battery.
From what I understand, you are wiring like this
Servo 5V - 5V Power module
The only way to keep millis() running is sleep mode is to sleep in
SLEEP_MODE_IDLE. Switching to Timer 2 would make no difference, as
all timers but the watchdog are stopped in other sleep modes. The
watchdog is horribly inaccurate, so you do not want to rely on it for
any kind of timekeeping.
I don't see much advantage to sleeping for 1 ms.
Sleeping for ...
In fact, for a project like this, you should use two Arduinos, one as SLAVE and the other as MASTER.
You mentioned 4 sensors for measuring water quality, but you will have more modules such as RTC and MicroSD to store the data.
So, I think you should use Slave to colect the data from sensors using the Tentacle Shield, and the other Arduino as Master, to ...
I would do as follows:
Arduino is in sleep mode
every x seconds (x depending on your needs), wake up then switch on and read one sensor after the other and transmit the results or whatever you want to do.
then go back to sleep
as you have 4 sensors, you can connect their outputs to the arduino analog inputs (or digital...)
you will ...
You can use a branded 5 V charger made for cars. You can directly connect this to 5 V pin of the Arduino.
By doing this:
you are protecting the Arduino from the noise as well as high voltage spikes coming from the car 12 V supply
protecting yourself and others coming in contact with the Arduino or the sensors connected to the Arduino.
You can also
The official page for the Nano 33 BLE Sense mentions various things including the datasheet for the light sensor. That appears to be much more sophisticated than an LDR.
According to the sensor documentation (above):
Upon power-up, POR, the device initializes and immedi-ately enters the low power SLEEP state. In this operational state the internal ...
As is described in this post from the arduino forum, There is a MOSFET switch in series with the USB connector +5V input line. If the battery booster 5V output is connected to the USB input jack, then it will automatically power the UNO whenever power is disconnected from the barrel jack, and will be automatically disconnected whenever at least 7.0V is ...
Please have a look at the schematics:
The USB connector uses a resistor (1500 Ohms) against the 5V net and a 3.6 Volt Z-Diode on it's (D-)-Pin. In addition to the current that is drawn by the microcontroller, this part of the circuit draws some extra ...
Instead of calling analogRead(), this sketch performs the equivalent actions by directly manipulating the hardware registers to begin a conversion, wait until the conversion is complete, and collect the converted value.
Just reading the final value is accomplished by the statements:
result = ADCL;
result |= ADCH<<8;
All of the statements following ...
Yes, you can simultaneously connect external power supply and USB. As explained in one of the answers, that you linked, the Arduino chooses it's power input through the supplied voltage on Vin/barrel jack. Vin has no direct connection to the VUSB, so the USB port will not get any voltage from the external supply, thus it does not get damaged.
BUT: Your ...
If you buy a 30V current-limiting power supply set to limit the current to 1.5A, you should be able to use it to power your LED light through a high power logic level MOSFET. You could control the MOSFET with a PWM signal from an Arduino and use that to vary the brightness of your light. With a little googling I found an adjustable power supply with an ...
"Ground" is just a lump of metal and each ground "pin" is connected to it. That includes the ground connection in the barrel jack. It's all one thing.
Wherever you connect your fan's ground to it's all ground. That is, as long as all grounds external to the Arduino are connected, ultimately, to the Arudino.
Most USB powerbanks will automatically turn off if there is not a minimum current draw to keep them turned on. The Arduino is obviously drawing current below the limit for the devices you have.
A couple of options:
Add some additional load to keep the powerbank on indefinitely. Of course this may waste power but that's part of the price to pay.
Find a ...
Your idea is sound, but your implementation is flawed.
First, you don't want to bother with "wake" and things like that - when the chip gets power it just starts from scratch - that's your "wake" signal. Your code will just be "Hold it on" and "Make a sound" followed by "Let it switch off".
You only need one ...