Powering the arduino nano with a Power bank

[narri]

I have a proyect using an Arduino mega rev3, with an ultrasonic sensor and a RGB LED to indicate the distance(calculated with the sensor), it is powered with a verbatin Powerbank, which is conected to the ground and to a resistor in the PCB, to drain the energy, which is the same as conecting to the VIN



Now I want the same but in a reduced size, for what I want to use an arduino nano, with the same equipment except the battery, but I do not know which battery to select (one without a turn on feature), and if i have to make a converted circuit or I can connect it to the VIN pin directly, or even to the USB.

[TomGeorge]

Hi,

I have a proyect using an Arduino mega rev3, with an ultrasonic sensor and a RGB LED to indicate the distance(calculated with the sensor), it is powered with a verbatin Powerbank, which is conected to the ground and to a resistor in the PCB, to drain the energy, which is the same as conecting to the VIN

Can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?
If you are using a 5V USB powerbank, you can connect it directly to the USB socket on the mega.
Thanks.. Tom..

[narri]

Hi Tom

Hi,Can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?
If you are using a 5V USB powerbank, you can connect it directly to the USB socket on the mega.
Thanks.. Tom..

I put the PNG file as an attachment, as you can see is not connected to the USB port directly because in that case the battery turned off sometimes, this is the reason I was asking if you know some manofacturer that have some small battery without that bug/feature, which is because it is not enough current comsumption.

[TomGeorge]

Hi,
The bank is a Lipo type, it has protection circuitry fitted to disconnect the battery when it gets too low and to protect it when it is being charged.
OPs image.

I would suggest you plug the bank in where it is supposed to be.

Can you tell us your electronics, programming, Arduino, hardware experience?

Tom...

[TomGeorge]

Hi,
If you are supplying 5V to Vin, then you will not be getting regulated 5V on the Mega, as Vin is connected to the input of the on board 5V regulator.

I do not see how the resistor you are connected to is providing the current needed to keep the bank switched ON.

Tom...

[rpt007]

If you are supplying 5V to Vin, then you will not be getting regulated 5V on the Mega, as Vin is connected to the input of the on board 5V regulator.

.. and it would not work at all as the built-in regulator needs at least 7V as mimimum input voltage.

[6v6gt]

If the power bank switches itself off when it considers that there is insufficient load on it, then you can sometimes get away with drawing current sporadically to trick it into remaining on.

I got the idea from an Web article somewhere and did some experiments and arrived at the solution of using a 47 Ohm resistor switched for 20mS every 2000mS ( 1% duty cycle) across the output of the power pack I purchased ( a PNY 10400mAh. 10400mAh that is at an undisclosed internal battery voltage).
I actually use a small 555 timer circuit for this with a transistor, but it would also be perfectly possible to use spare Arduino pin, maybe with a transistor or different resistor / timing values to stay in spec of the Arduino.

[narri]

.. and it would not work at all as the built-in regulator needs at least 7V as mimimum input voltage.

Hi,
If you are supplying 5V to Vin, then you will not be getting regulated 5V on the Mega, as Vin is connected to the input of the on board 5V regulator.

I do not see how the resistor you are connected to is providing the current needed to keep the bank switched ON.

Tom...

Sorry but with that it is currently working as I am using the resistor in order to draw the energy, it was an idea I found in a blog nearly a month ago. As it is working my question is if there is a way of doing it in the nano as in the mega, or I shoud use a circuit as in:

http://www.instructables.com/id/USB-External-Battery-Packs-on-Arduino-turns-OFF/

[narri]

If the power bank switches itself off when it considers that there is insufficient load on it, then you can sometimes get away with drawing current sporadically to trick it into remaining on.

I got the idea from an Web article somewhere and did some experiments and arrived at the solution of using a 47 Ohm resistor switched for 20mS every 2000mS ( 1% duty cycle) across the output of the power pack I purchased ( a PNY 10400mAh. 10400mAh that is at an undisclosed internal battery voltage).
I actually use a small 555 timer circuit for this with a transistor, but it would also be perfectly possible to use spare Arduino pin, maybe with a transistor or different resistor / timing values to stay in spec of the Arduino.

Thanks in advance for the help. How is it done the switched, coud it be done with a condenser?, if it that the case do you have any circuit implementing that?

[6v6gt]

Here is what I use to suppress the Auto Power Off "feature" of my powerbank.

[rpt007]

Sorry but with that it is currently working

-> by connecting it via Vin?

Never - the regulator definitely needs at least 7V. This is what I was referring to and not, if you are connecting your power bank to the USB port itself. This will then bypass the onboard regulator and will be powered directly via the USB +5V.

[TomGeorge]

Hi,
I have looked at my mega which is the same as you have pictured.

The green component is a 500mA FUSE in the 5V supply from the USB socket.

So it should make no difference between your connection and using the USB.

Your connection may not be safe for the mega as it could be on the wrong side of the fuse, and so not be protecting your mega or the bank.
I don't see how this is keeping  your bank awake if using the USB socket doesn't.

Tom...