Can I increase the 5V amparage without destroying my arduino uno

Thread Starter

Miquel19

Joined Aug 16, 2020
37
Yes, and/or use battery voltage whenever possible so you don't waste as much power in voltage regulators.

What is the voltage tolerance of the components being used? What is the current capacity of the battery you're using (is it a 9V transistor radio battery)? How much runtime do you want?
All the components work at 5V, less the motors and motor drivers that work as much at 10.8V(if I pass this limit, the motor drives burns itself).
Actually I'm using normal batteries of 1.5V, but I will use lithium-ion batteries. I want to connect two 3.7V lithium-ion batteries serial, but maybe I will need to connect more in parallel to get more amperage.
I would like between 30 minutes and 1h of runtime.
 

Irving

Joined Jan 30, 2016
3,845
Sorry but I don't have the led matrix datasheet. I believe that what they put on amazon was true (I don't know it, but I can't do more). Here there is the link where I bought it (it's amazon Spain) https://www.amazon.es/AZDelivery-MAX7219-Matriz-Pantalla-Arduino/dp/B07CRF13ZQ/ref=sr_1_5?__mk_es_ES=ÅMÅŽÕÑ&crid=3F5A7ZTZEJDEU&dchild=1&keywords=matriz+led+8x8&qid=1599837610&sprefix=matriz+,aps,180&sr=8-5&th=1

I will be careful not doing loops and using only one common ground.

Now I can't test what you said, because my batteries had already finished. I will buy some more and test the capacitors. I will also order a converter to get another 5V wire and test the idea.

I don't know what is wrong with the Wemos d1 mini wiring. I took it from a tutorial and it has always worked well. What should I do to solve it?
Link to the tutorial - maybe its the way you drew it...

Yes, I saw the same matrix on Amazon UK... not yet convinced it'll be that low...

Below is a partial recreation of your drawing (I didn't add the LED Matrix). The audio and motor drivers will have spikey noisy power usage which may cause problems esp as the battery volts drop.... so a moderately large capacitor 1000uF with a 100nF ceramic in parallel will help keep things quiet. These should be on the individual boards but they never add enough. You might get away with smaller capacitors but i don't know what motors you're driving.... Keep the wires to the motor controllers from the battery as short as possible.

I note your battery life requirement. What motors are you using and what are they doing? I can see they are operating as two motors in tandem using the same PWM inputs.

1599844174403.png
 

Thread Starter

Miquel19

Joined Aug 16, 2020
37
The 2N7000 is an N-channel MOSFET in the TO-92 package that will turn ON with only 2V applied to its gate. When ON it can conduct up to 500mA & 60V for a max of 400 mW load. If more needed then the FQP30N06L N-channel MOSFET in the TO-220 package can turn on at 1V at its gate and conduct 5A & 60V for a max of 79W. Both are readily available and relatively inexpensive components to have when needed. The idea is that the Arduino is the control system, not the powerhouse. The Arduino does not have that many mAs available and they should only be used for the controls. Also, with the loads you say you have your 9V battery will have a very short life. USB can provide ~400-500 mA. More than that you will want to go to a wall wart PS that has more capacity. Not sure exactly what those breadboard power supplies are good for. Have several (they came as freebies) but never liked or used them as there are better solutions readily available.

Edit: When ON the gate on the 2N7000 will draw 1mA, the FQP30N06L 500uA. That is why they are used for logic control of power users. Low turn-on Voltage, fully on @ 3.3V & 5V. Plus extremely low current draw to turn on.
Wow, I had never thought about what transistors are useful for. But if I want to use it I would still need a conversion to 5V (all the modules I'm using need to powered with 5V). I'm using a battery because I'm crafting a control remote car that works with wifi (I have also build a remote controller). For this reason, I need good powering. And yeah, you are right. I won't have much runtime (I don't want to have lots of batteries in the car).
 

Thread Starter

Miquel19

Joined Aug 16, 2020
37
Link to the tutorial - maybe its the way you drew it...

Yes, I saw the same matrix on Amazon UK... not yet convinced it'll be that low...

Below is a partial recreation of your drawing (I didn't add the LED Matrix). The audio and motor drivers will have spikey noisy power usage which may cause problems esp as the battery volts drop.... so a moderately large capacitor 1000uF with a 100nF ceramic in parallel will help keep things quiet. These should be on the individual boards but they never add enough. You might get away with smaller capacitors but i don't know what motors you're driving.... Keep the wires to the motor controllers from the battery as short as possible.

I note your battery life requirement. What motors are you using and what are they doing? I can see they are operating as two motors in tandem using the same PWM inputs.

View attachment 216922
The tutorial is in Spanish (the schematic is at minute 11:42);

I also feel that 160mA it's too low for the 8x8 led matrix, but...

I'm using 4 TT motors. I'm controlling them 2 and 2 (I'm using 2 DRV8833, one driver for 2 motors). I have put a capacitor to each motor. The capacitor is the P22j63. I'm controlling the motors with PWM, so if needed, I can use less power on the motors.

Basically, my project is making a remote control car and its respective controller. For communication, I'm using the esp8266. Then de DFPlayer mini and the 8x8 led matrix are just complementing. For the battery I will pick some lithium-ion batteries (those ones of 3,7V) Maybe I will need to pick 4 of them, and connect in parallel two serial batteries (to get more amperage)
 

SamR

Joined Mar 19, 2019
5,031
The digital I/O pins on the Arduino are capable of sourcing up to 40mA each so attaching them to the gate which needs only 1mA or less is no problem. That is why switching transistors are used. They require very little power to turn them on and can conduct more power than the Arduino is capable of providing. There is quite a bit to learn as to how Arduinos can be used.
 

Thread Starter

Miquel19

Joined Aug 16, 2020
37
The digital I/O pins on the Arduino are capable of sourcing up to 40mA each so attaching them to the gate which needs only 1mA or less is no problem. That is why switching transistors are used. They require very little power to turn them on and can conduct more power than the Arduino is capable of providing. There is quite a bit to learn as to how Arduinos can be used.
Yeah, I will look about it, it seems interesting
 

Deleted member 115935

Joined Dec 31, 1969
0
The digital I/O pins on the Arduino are capable of sourcing up to 40mA each so attaching them to the gate which needs only 1mA or less is no problem. That is why switching transistors are used. They require very little power to turn them on and can conduct more power than the Arduino is capable of providing. There is quite a bit to learn as to how Arduinos can be used.

Totally agree with what @SamR posted,
a note for any future readers,
there is also a limit on how many IO can have 40mA at once, and how many you can switch at once,
its in the specs of the chips, but ruel of thumb one or two is no problem, 8 or more is problem, between, user beware.
 

Thread Starter

Miquel19

Joined Aug 16, 2020
37
Link to the tutorial - maybe its the way you drew it...

Yes, I saw the same matrix on Amazon UK... not yet convinced it'll be that low...

Below is a partial recreation of your drawing (I didn't add the LED Matrix). The audio and motor drivers will have spikey noisy power usage which may cause problems esp as the battery volts drop.... so a moderately large capacitor 1000uF with a 100nF ceramic in parallel will help keep things quiet. These should be on the individual boards but they never add enough. You might get away with smaller capacitors but i don't know what motors you're driving.... Keep the wires to the motor controllers from the battery as short as possible.

I note your battery life requirement. What motors are you using and what are they doing? I can see they are operating as two motors in tandem using the same PWM inputs.

View attachment 216922
Schematic_Cotxe_2020-09-12_12-42-29.png
This is my schematics now.
 

Thread Starter

Miquel19

Joined Aug 16, 2020
37
Totally agree with what @SamR posted,
a note for any future readers,
there is also a limit on how many IO can have 40mA at once, and how many you can switch at once,
its in the specs of the chips, but ruel of thumb one or two is no problem, 8 or more is problem, between, user beware.
That limit is a problem. But I'm only using the pins for controlling and sending orders to the wemos d1 mini, the motors, the matrix, and the DFPlayer mini. I would have problems with that? I will be powering that with an extra rail of 5V.
 

SamR

Joined Mar 19, 2019
5,031
One of the advantages of switching transistors is that they do not have to conduct just 5V. Yes, 5V to the base or gate turn them on but what they can conduct is limited only by the max voltage specification for the transistor. What you do have to watch is the wattage rating of the transistor since exceeding it will burn the transistor out. The other thing that needs to be mentioned is the use of optical isolators to protect the Arduino from hi voltage. Yes, a transistor can switch 120VAC but you would not want the transistor to short out and deliver 120VAC to the pin of the Arduino. So there are some safeguards to be considered when dealing with transistor switching of higher voltage than the Arduino is rated for.
 

Irving

Joined Jan 30, 2016
3,845
That limit is a problem. But I'm only using the pins for controlling and sending orders to the wemos d1 mini, the motors, the matrix, and the DFPlayer mini. I would have problems with that? I will be powering that with an extra rail of 5V.
Indeed, so all the discussion on output current limits for Arduino pins, and the use of external MOSFETs as auxilary switches, whilst interesting and valid, is irrelevant to what you're doing right now, and has no bearing on your current consumption. So note for the future and carry on!

The tutorial is in Spanish (the schematic is at minute 11:42);

I also feel that 160mA it's too low for the 8x8 led matrix, but...

I'm using 4 TT motors. I'm controlling them 2 and 2 (I'm using 2 DRV8833, one driver for 2 motors). I have put a capacitor to each motor. The capacitor is the P22j63. I'm controlling the motors with PWM, so if needed, I can use less power on the motors.

Basically, my project is making a remote control car and its respective controller. For communication, I'm using the esp8266. Then de DFPlayer mini and the 8x8 led matrix are just complementing. For the battery I will pick some lithium-ion batteries (those ones of 3,7V) Maybe I will need to pick 4 of them, and connect in parallel two serial batteries (to get more amperage)
The tutorial is correct and identical to what I drew. Must be the way you transferred the info to your schematic. :)
 

Thread Starter

Miquel19

Joined Aug 16, 2020
37
Indeed, so all the discussion on output current limits for Arduino pins, and the use of external MOSFETs as auxilary switches, whilst interesting and valid, is irrelevant to what you're doing right now, and has no bearing on your current consumption. So note for the future and carry on!


The tutorial is correct and identical to what I drew. Must be the way you transferred the info to your schematic. :)
I have it like this. Its ok?Schematic_Cotxe_2020-09-12_17-18-50.png
I will make what you said with the DFPlayer mini, and when I have tested with the batteries I will say something. Thanks a lot
 

dl324

Joined Mar 30, 2015
16,846
Yeah, I will look about it, it seems interesting
It should be pointed out that the 40mA output current that's often quoted is an absolute maximum parameter and devices aren't intended to operate at those levels for "extended" periods of time according to Atmel:
clipimage.jpgclipimage.jpg

Also note that the absolute maximum current for the VCC and GND pins is 200.0mA. Note also that the absolute maximum current per I/O pin is 40.0mA, which implies that 40.1mA will damage the pin.

Unless you want to risk damaging the microcontroller, you should plan on not operating many of the GPIO's at high currents; unless you've taken the maximum current for all I/O's plus current used by the uC into consideration.

Fairchild included this in their absolute maximum warning:
clipimage.jpg
 

Thread Starter

Miquel19

Joined Aug 16, 2020
37
It should be pointed out that the 40mA output current that's often quoted is an absolute maximum parameter and devices aren't intended to operate at those levels for "extended" periods of time according to Atmel:
View attachment 217000View attachment 217001

Also note that the absolute maximum current for the VCC and GND pins is 200.0mA. Note also that the absolute maximum current per I/O pin is 40.0mA, which implies that 40.1mA will damage the pin.

Unless you want to risk damaging the microcontroller, you should plan on not operating many of the GPIO's at high currents; unless you've taken the maximum current for all I/O's plus current used by the uC into consideration.

Fairchild included this in their absolute maximum warning:
View attachment 217003
Hi, sorry for my lateness. I think that I won't pass this limit. I mean, for only transmitting data I will not overcome this limit right?
 

Irving

Joined Jan 30, 2016
3,845
Nothing you are doing will load any of the Arduino I/O pins remotely near their limits... you don't need to worry. But I note in your last diagram you're still powering the DFPlayer, Wemos and LEDs off the Arduino 5v - as previously discussed this won't work, at least not for long - once you start exercising all those peripherals in anger... though before that its likely you'll see odd behavours as the 5v rail experiences 'brown outs'.
 
Last edited:

Thread Starter

Miquel19

Joined Aug 16, 2020
37
Nothing you are doing will load any of the Arduino I/O pins remotely near their limits... you don't need to worry. But I note in your last diagram you're still powering the DFPlayer, Wemos and LEDs off the Arduino 5v - as previously discussed this won't work, at least not for long - once you start exercising all those peripherals in anger... though before that its likely you'll see odd behavours as the 5v rail experiences 'brown outs'.
Mh, okay, thanks, I was getting confused
 

djsfantasi

Joined Apr 11, 2010
9,156
@Irving identified two limits you need to design for with an Arduino. I’m posting this to clarify what those limits are.

The first limit concerns the GPIO pins. They can only supply a maximum of 40mA per pin but practically speaking, you should keep their current draw at 20mA. And the TOTAL of all pins must be kept below 200mA.

The second limit applies to the 3.3V and 5V pins used to power shields and peripherals. That limit depends on the Arduino model. For an Uno R3, the pin can supply 400mA if powered by USB or higher when using the power jack. It’s practical limit is 800mA
 

SamR

Joined Mar 19, 2019
5,031
As I pointed out several times. Which is why I brought switching XSTRs to the table for consideration. I still don't know if it sank in. Ah well... Something about leading to water comes to mind...
 

djsfantasi

Joined Apr 11, 2010
9,156
As I pointed out several times. Which is why I brought switching XSTRs to the table for consideration. I still don't know if it sank in. Ah well... Something about leading to water comes to mind...
Came to my mind as well. I posted this to (hopefully) clarify that there are TWO limits which are separate and different. I thought that might be the source of the TS confusion he mentioned in his last post. I didn’t mention that the Arduino load is included in the latter limit. I wanted just to be sure the TS understood the two limits.
 

Irving

Joined Jan 30, 2016
3,845
All of which is true people, but the TS was specifically asking about the 5v rail output when powering from Vin.

He was confused because he couldn't see how the discussion on pin capacity and switching transistors applied to his situation, which it doesn't.

The discussion on the 5v output is relevant, and we ascertained he will almost certainly exceed that at some point as he develops his software and starts exercising the peripherals.
 
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