Hello everyone! I am new to the Arduino platform and in desperate need of help for a particular project that I am working on. I am using Arduino Uno and I am trying to connect 5 sensors to the board via a breadboard.
The List of sensors I am using:
The issue I am facing I believe (not completely sure) is that the Arduino is not able to supply enough power to all the sensors simultaneously. I tried and tested each sensor individually and they were working fine. Even the DHT, Ph, and light sensors connected simultaneously are able to function properly and give accurate readings, however, adding any more sensor than that causes the DHT sensor to give "nan" values.
I tried connecting the Arduino to an external supply as well in which case it gives readings of 4 of the 5 sensors, however, the readings of the pH sensor ( which is directly related to the voltage supply to the sensor) drop by a value of almost 1, which is a pretty huge drop.
It would be great if someone can suggest a solution or give advice on how to tackle this situation, Thanks.
What is "external power"? Where did You connect it? Which controller is uded?
Ude a good 5 volt supply and connect it to the 5 volt, or Vcc pins on sensirs and controller.
The Arduino is a micro controller, it is not a power supply. You need a 5V power supply connected to the 5V pin or the USB connector, an old phone charger would be a good choice. You can then power things from the 5V power supply.
As a hint for future, make a point of collecting old power supplies from electronic equipment that is being thrown away, that way you will always have a power supply for your projects.
Railroader:
What is "external power"? Where did You connect it? Which controller is uded?
Ude a good 5 volt supply and connect it to the 5 volt, or Vcc pins on sensirs and controller.
Sorry for not clarifying, by external power I meant I have connected the Arduino Uno to an adapter of 12V.
PerryBebbington:
The Arduino is a micro controller, it is not a power supply. You need a 5V power supply connected to the 5V pin or the USB connector, an old phone charger would be a good choice. You can then power things from the 5V power supply.
As a hint for future, make a point of collecting old power supplies from electronic equipment that is being thrown away, that way you will always have a power supply for your projects.
I have connected the Arduino to a 12V adapter through the DC power jack, but the sensors are still not functioning properly.
temp07:
I I have connected the Arduino to a 12V adapter through the DC power jack, but the sensors are still not functioning properly.
There's a tiny little regulator on the board that in simple terms takes excess voltage and converts it to heat. Out of 12V you only want 5V, so 7V (more than half!) gets wasted as heat. The tiny little regulator gets hot then shuts down.
You need a 5V power supply connected to the 5V pin.
temp07:
Sorry for not clarifying, by external power I meant I have connected the Arduino Uno to an adapter of 12V.
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That is the fault.
Read reply #1, #2, and perrys reply]
PH sensor based on my experience is the most sensitive sensor to change the behavior while work with other sensor, really pain in the ass when debugging.
so my approach was disconnect all other sensor while reading PH value with mosfet. and mosfet triggered by digital pin.
A very real danger is that the obsolete tutorials on the Arduino site 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 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.
If you are asking this question, it is highly likely that you will wish to connect something else. In which case, the answer is regulated 5 V.
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 (older) 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.
A practical power supply for the Nano (or UNO, Pro Mini, Leonardo etc.) is a "phone charger" with a USB output connector for 5 V, generally up to a couple of Amps though you can not feed more than 500 mA through the USB connection.
If you want to power it from 12 V or a car system, you need a 5 V switchmode "buck" regulator to supply the 5 V.
Paul__B:
A very real danger is that the obsolete tutorials on the Arduino site 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 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.
If you are asking this question, it is highly likely that you will wish to connect something else. In which case, the answer is regulated 5 V.
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 (older) 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.
A practical power supply for the Nano (or UNO, Pro Mini, Leonardo etc.) is a "phone charger" with a USB output connector for 5 V, generally up to a couple of Amps though you can not feed more than 500 mA through the USB connection.
If you want to power it from 12 V or a car system, you need a 5 V switchmode "buck" regulator to supply the 5 V.
Thank you so much Paul for such a detailed answer! It really helped in providing insight into the issue I am facing.
I just have one (pretty noob) question, I am not getting how exactly to connect the phone charger to the 5V pin and where(or how) to connect the Vcc pins of the sensors to the Arduino?
It would be really great if you could tell me how to do that. Thank you!
Ah, well, given the phone charger has a USB "A" socket on it, you "sacrifice" a USB cable to split out the red and black wires to connect to the Arduino pins and to the other 5 V devices. Neater if you get a USB plug to which you can connect your own wires as ready-made USB cables frequently have quite flimsy wire.