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Topic: Arduino Nano Expansion Board (Read 17305 times) previous topic - next topic


Sep 03, 2017, 09:02 am Last Edit: Sep 03, 2017, 09:08 am by ardy
I have one of these Arduino Nano expansion boards.

Does anyone have a schematic for these?

The board has a 3.3 volt regulator. How is it connected to Nano?



Sep 03, 2017, 11:19 am Last Edit: Sep 03, 2017, 11:20 am by Whandall
I think it only sources the extra 3.3V connectors.

Ah, this is obviously some strange usage of the word 'safe' that I wasn't previously aware of. (D.Adams)


Ok. So the DC jack goes straight to the Nano's Vin pin then?


If straight means via a diode and buffered by capacitors, yes.
Ah, this is obviously some strange usage of the word 'safe' that I wasn't previously aware of. (D.Adams)


Sep 03, 2017, 12:20 pm Last Edit: Sep 03, 2017, 12:28 pm by ardy
I think I actually found a schematic for this type of board.


According to it, the power goes from the shield to the Nano, then returns back to the shield as VCC (5V), before being downregulated to 3.3V. Is it your understanding too?

I think it would better if the shield converted DC to 3.3V directly, without having to go through the Nano first.


Then maybe you would prefer a Nano IO shield (wich has a NRF24L01 and XBEE Bluetooth socket)

Ah, this is obviously some strange usage of the word 'safe' that I wasn't previously aware of. (D.Adams)


That is a nice board, but pricier, and kind of a waste of real estate if I don't need RF.


Ah, this is obviously some strange usage of the word 'safe' that I wasn't previously aware of. (D.Adams)


I have one of these and I can not get is to run servo motors. Does anyone know how?


The basic problem with this board is that the servo V+ is connected with the output of the Nano board regulator.  for example if you have a 6 volt battery the nano 5 volt power comes  from a small three terminal regulator that can't handle the servo current needs. 

Thus you need to rework the board to run the servos directly from the Battery 


Hello guys, new to arduino here. Does anyone know if you can connect 5V regulated to power (input) a nano connected to this board? Do I just peak one of the 5V connections on the board and hope it works?


Hi everyone, I am a complete newbie at this and need some help, I am a bloody good hardware engineer and thought in my retirement i would try  a project using an Arduino V3 with expansion IO board.
 I have 3D printed a hand and need to use 7 servos to move the fingers etc.

 OK, I have the coding, and programmed the Nano V3.  Using an external power supply 3Amp 7.2 volt battery, servos all centre, but I have no switching on any of the inputs.

The code has four versions in it, i have tried to use it as is, and also taken out three versions, this compiled OK but still no switch control.
 I am beginning to think that the nano V3 needs a separate supply to the servos.

The hand is on

The I/O board I am using is from eBay

Any help in the code and how to get this switched part working would be so nice.


   What do you mean "no switch control"?
   Besides that, with that I/O board you are definitely not going to power 7 servos. At the most one. This I/O board can handle the same power us the nano itself - 500mA max - but your servos need much more power (amperage) to work at the same time. If you see the schematic at the first link you provide, the dude/gal is using a custom circuit to power the servos separately from the nano - one power supply for the 7 servos and one for the nano (with a common ground). So the nano controls the 7 servos but they are powered from a seperate power source. 
   I'm also new to electronics in general so I'm not 100% sure I'm right, so take it with a grain of salt. [/pre]


Hi deathorion, yes i can see what you are saying here, i am making the switch assy as per the schematic now. just waiting for some solder pins to arrive for the nano.

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