Trying to make sense of the description, so let me get this straight...

Two 12v batteries run in parallel to provide 12v to each of the EZ-B V4s? Or is each supplied by one battery with a common ground?

What's powering the EZ-B V3 you mentioned?

Every device connected to the EZ-B V4s are going to have their own regulator?

What is supplying the voltage for the wheelchair motors and sabertooth?

The EZ-B V4 camera cable can be extended however either requires you to cut the cable and join it with some extension wire between or build an extension cable. Currently there is no wireless camera (even when they do release the wireless camera it will require a power source)

What are the voltages of the sensors? Are they going to have a regulator each or one for multiple sensors? What voltage is the regulator? How many amps can they handle? What demand do the sensors have? What are the recommended voltages for the sensors? (note, a lot of sensors will work on a voltage range i.e. 3.3v to 5v but give more accurate readings when supplied with the correct voltage)

Perhaps if you are unsure of if it will work you should take some time to work out the schematic for the entire robot. It's a time consuming exercise but is worth doing. It will help flag up any issues you may have and it is a record for if you want to add, upgrade or replace any parts in the future. Here's an old version of Melvin's schematic which proved invaluable on more than one occasion.

Melvin has since gone through a lot of changes and, with the V4 now being used in him there are more which will come. Using this schematic I can easily see which bits I can remove, which need regulators etc. With the additional information included on the PC version of the schematic it also tells me the load of each servo, load on each regulator, required voltage at each point etc. I could even go as far as to calculate the voltage drop at each device if I expected issues with the voltage drop (I don't since the mV per Amp per Meter drop of the cable I am using is very low and lengths are short)

So basically, my advice is to draw a schematic. There are many free programs that can help you. Express PCB for instance, AutoDESK Circuit.io is another choice and I am sure there are a lot more out there. Or do it by hand, the old fashioned way.

I agree with Rich. A schematic is valuable and necessary on just about any complex collection of electronics. I remember over a decade ago when I first looked at a schematic of a pinball machine trying to figure out how to fix the dam thing. I was totally lost and thought "What have I gotten my self into here". However once I worked through the logic of it with the reference key showing what the parts were used it all kinda flowed together. I now have pages and pages of handwritten schematics of the innards of my B9 and have more undocumented areas to still do. I plan to someday convert them to line drawing like Rich shows. I've up graded B9 several times, blown up a few things that needed fixing and had to integrate new systems into him. Without the schematics as a road map I would have had a very hard time doing any of this and keeping him from going up in a ball of flame after the work. eek

You gotta do all that you're doing to make sure everything gets what it needs and works. You can plan and calculate but In the end ya never really know if all is well till you flip the switch. That's the real test. cool If not, well, you use the schematics you hopefully wrote before, during and after the work to follow to see what needs to be fixed.

From what I hear, its exactly what my plan is. Great minds think alike!

@Rich,

Same two batteries in PAR supplying +12v to Everything. From the EZB-3, +5v to some sensors. EZB 3 supplying control of Saber-tooth and two wheelchair motors. don't know the voltages of the PIRs yet, Seemed to work on the Analog port ok before EZB 3 burnt up. Now I will use a different EZB 3.

I will continue to update this thread with information as I know it.

THANK YOU ALL FOR THE GREAT INFORMATION!

In that case, provided everything is regulated as required it should work. Just make sure you parallel the batteries since putting them in series would cause problems.

The PIRs I expect are +5V

Just be aware of the load of the sensors, if you load up an EZ-B V3 with sensors which have a large load they may cause brownout issues. It would take a lot of sensors as I believe most sensors draw only mA so it would take a lot to push past the 5A limit of the V3.

If you need help with the schematic I'm more than happy to help when I have the time but it should be pretty simple.

Thanks!

Well, I spent one hour. I only got the two batteries, a Diode and a couple of terminal strips made. Then, I could not print it or save it. So, it was useless to me. I will try some other method.

I am a turtle. It will take much longer than I have. I will just stick with a hand drawn schematic.