What type of 6V connector is being used?

faq
pivotpi

#1

PivotPi comes with a 6V cable to supply power from AA batteries. What type of connector is being used? I want to order some, so I need more info than just Molex or JST. Thanks!


#2

@Sparkletron: you can use something like this or this for that connector.


#3

Thank you. There are umpteen million connectors out there, and it’s very challenging to identify them. Kudos to Dexter for including a very high quality 9V batter snap. Don’t think I didn’t notice!

Incidentally, on the circuit board, where it says “6V only”, it would have been better if it had said “6V MAX” or even better “SERVO PWR”. The text as is implies that you must supply 6 and only 6V, which of course isn’t true, as it depends on the servo.


#4

@Sparkletron,
Thanks for the feedback and.

I’ll let the team know about changing the label and 6V MAX does sound better than 6V only and we would try changing that in the next round of hardware or make the documentation more clear.


#5

Is there a connector with cable that can power the pivotpi from a usb power bank? Something I can buy out of the box online?
Thank you.


#6

Hi @fadilonline,


The connector

The connector that’s used on the PivotPi is called a Molex KK. But this is its technical name.
Generally, they are known as Polarized Connectors.
Here’s a link to these connectors on sparkfun.

So the spacing between the pins is 2.54 millimeters.
This means you have 2 options of connecting a battery to the Pivot Pi connector-wise:

  1. Buy a polarized housing connector from sparkfun and solder wires to it.

  2. Or use a standard 2-pin header to which you can then solder some wires that go to the battery - I’d go with this route if you already have some header pins.


The power supply

Generally servos can work well between 4.8V and 6.0V, so I think a USB power bank could do the job.
Don’t forget that the servos can have really big spikes in the drawn current for very short periods of time, so I wouldn’t supply a Raspberry Pi from the same power bank, as that would cause a crash of the Raspberry Pi.

And the last important thing is that a USB power bank can give a relatively small current (up to 2.5 amps), so you won’t be able to power too many servos with the PivotPi.


Hope this helps you on your project.
If there are any more things you need to know, we’ll be happy to help you.

Thank you!


#7

What about powering a PivotPi from RPi USB?


#8

Hi @graykevinb,

I think I’ve covered that in my previous post. Here it is:

so I wouldn’t supply a Raspberry Pi from the same power bank, as that would cause a crash of the Raspberry Pi

Powering the Raspberry Pi from its USBs or from the power supply is basically the same deal.

Is this at what you were referring?

Thank you!


#9

So I’m a little confused. According to what you said is powering a PivotPi from the RPi’s USB ports a bad idea?


#10

Hi @graykevinb,

Yeah it’s a bad idea to power your PivotPi from a Raspberry Pi.


That’s because the PivotPi requires large amounts of currents for very short periods of time - especially when you have multiple servos that are being actuated all at once.
These very short periods of time when the drawn current is large can take the Raspberry Pi down.

That’s why is a good idea to have separate power supplies and it also makes sense - that’s redundancy.


Maybe you think I’m referring to the Grove ports that are used to connect the PivotPi to the Raspberry Pi.
I’m referring to the 2-pin 6V port.


Thank you!


#11

OK, thanks! I guess if you could the included cable would be USB. :slight_smile:

Thanks @RobertLucian!


#12

BTW, I bought a 2 wire (power and ground) USB cable from Amazon. It is used to power fans in CPU cases - look for fan power usb cable PC on Amazon - it powers the Pivot Pi out of the box.