Power Pi and Motors

The PicoBorg Reverse does not have a DC/DC fitted, so it does not supply the 5v for running the Raspberry Pi.

What we do have is another board called BattBorg, which does provide the 5v to the Raspberry Pi.
The BattBorg also fits neatly onto the PicoBorg Reverse to make a single attachment:

You would need to connect the batteries to both the PicoBorg Reverse and the BattBorg to make this work, but they can share the same battery pack (See our DiddyBorg build instructions for an example here, towards the bottom).

As a general rule of thumb it is not a bad idea to have motors which are a slightly lower voltage than the power supply.
For example 9v motors with a 12v battery pack would work well.
You can set the output voltage to the motors using the provided PicoBorg Reverse software.

robotpibot,

I can appreciate your confusion, it took me a short bit to sort out how exactly to hook all of this up as well. However, once I got it, I realized it actually is quite simple.

The key is the fact that the PicoBorg Reverse has the ability to drive the motors with a separate power supply. Therefore, if you have motors that require more power than the Raspberry Pi can handle, they would effectively be on a separate circuit. That power source goes through the middle screw terminals on the Reverse.

In the case of the DiddyBorg, a single battery pack is sufficient for both the motor drive and the Raspberry Pi. So a single 9v power connector is being connected to both the BattBorg and the PicoBorg Reverse in series, which is then plugged into the one battery pack.

Guys, I have a question I'd like to put up for some consideration..... just to get some more opinions on the situation. I apologize if it seems like I'm hijacking this thread, but it does match this overall topic very well.

With my current bot project, I am using 2 8x AA battery packs; one is going to the BattBorg and one to the PicoBorg Reverse. I've been wanting to put a switch in the line so I don't have to disconnect them to turn it off; rather than having two switches I'd prefer to have one though. What is the ideal way to turn this into one circuit without undue drain on the batteries?

The current charge going to the motors is sufficient for the time being (that may change if/when I rebuild the gear boxes and swap out the motors) so I don't really want to put the two battery packs in series and increase the voltage. Perhaps aligning the two separate packs in parallel with each other and connecting them to the two boards in series?

--Cody E.

Right, and that's simple enough to do.... certainly one of the options I've considered (though neglected to mention.) However, I am somewhat curious what you think of the idea of putting the two packs in parallel?

This is the chassis of the guy I've been building: http://youtu.be/1O1GPlPJWG0

I'm ultimately looking for the ideal setup between a host of concerns:

• Enough voltage to the motors to allow it to run on any common flooring surface
• Low enough voltage to keep gear noise to an acceptable minimum (<=10V)
• Prolonged battery life to Raspberry Pi
• Simple recharging process
• Power cost

I have a handful of NiCad packs from various RC cars ranging from 5-9V; I considered using one or more of those due to their lifespan and ease to charge. However, I don't want to design around something that is more expensive to replace when it finally does wear out. I also have a wonderful little power box that holds 4 18650 LiIon cells; that is great because I have a TON of those from salvaged laptop power packs. However, it is set up to output through USB, so 5V and roughly 1A. Alone it might be sufficient for the RPi, but it would defeat the purpose of having the BattBorg, and doesn't last quite as long it seems.

Ideally I would love to be able to design something with which I can switch it to "Charge" and plug a barrel jack right into the chassis and have it recharge without having to pull the batteries out. That would be a piece of cake with NiCad or LiIon; I've never attempted anything of the sort with rechargeable AA (aren't they NiMH?)

--Cody E.

As part of their Cyber Monday yesterday, Sparkfun.com had one of their LiPoly charger/booster boards 50% off. So I ordered that and a 2000mAh pack. I also have a small 3v solar panel that I've never used, but which can be added to the charger board. The voltage from the LiPo pack is of course quite a bit less than the other battery packs that I have on the bot right now, but I am anxious to start playing around with it to see how I can work it in conjunction with the BattBorg!

Hello,

I have bought a Diddy Borg on 08/2016 and I have not mounted it until today.

My pi is configured correctly and works fine, but when I install it on the
Diddy Borg, it seems that the PicoBorg Reverse don't feed it with the 5V trough the pins (I have
measured it with a voltimeter). I have tested and there is 5V on the picoBorg Reverse inputs and
in the BattBorg.

Is a possible malfunction on the PicoBorg Reverse?

Thank you
(My order is 21387)

Hello again,

I have measured on the pins of the picoborg reverse that will feed the pi (without the cable) and have 0 V.

I don´t know if the BattBorg is supllying 5V, I only know that it have 5V on his entries.

thank you

I think you are right, I have used a power supply of 5V alone. I will try with 7.5 V, and I will say you something.

Hello,

I have used a 12V power supply, and the DiddyBorg works perfectly.

thank you very much