Mohamed.r
South Africa
Asked
— Edited
Resolved by Dunning-Kruger!
I plugged in 2 continuos rotation servos to my ezb one in D0 the other in D11 and selected continuos rotation Movement Panel while configuring i clicked on the test button and it worked my servo moved front back and stopped properly but when I click save and press any arrow it doesn't work and then after pressing stop my ezb disconnects.
When testing, you can run both servos I believe. Press forwards test on 1, and forwards test on the other, running both at the same time, and see if it burns out. If not, its a bug.
If they are rechargeable NiMH, they should be OK running 2 servos with 6 of either mah rating. The nah rating tells you how long they will last, not how many amps they can deliver all at once. Rechargeable Alkaline can not meet the inrush current requirements and the EZ-B will brown out. Non-rechargeable Lithium AA's are OK, but wasteful. Alkaline are not. NiCD (if you can even still get them) can not meet the inrush current requirements either.
Personally, I think EZ-Robot should add a LiPo, Charger, and the Adapter plug to the Dev kit and raise the price accordingly. This issue happens too often. But you can get a 7.4v 2S Lipo at any hobby shop that sells R/C cars or planes or easily find them on-line in your own country and not need to pay the international shipping rates.
Alan
Personally I recommend not using rechargeable "AA" at all and I agree with Alan, a Lipo and recharger should be included in the ez robot dev kit...
Example
http://data.energizer.com/PDFs/NH50-2500.pdf
In any event, you don't have enough current or amps available for what you are trying to do. Its not the EZ-B, its the inrush of current needed by the servos that is causing the disconnect. This has been discussed many times in this community. Use the search feature and look up "Inrush Servo" and enjoy the reads. There is a lot of info available from many different users.
I also agree that the dev kit should include a battery but I think it has something to do with laws about shipping LiPO batteries outside of enclosures or something. It seems like this was mentioned by Jeremy or DJ before.
see link a bomb proof bag for lipo's,gets you thinking.
lipo bomb bag
i like the idea of putting a lipo and charger in the kit.
Hunter's robot ran great on 1350 Ni Cd rechargeable batteries.
He is using continuous rotation servos.
His robot ran prior, and recorded 4 videos after that.
He gave it a good test following the red ball, many servos, and was using the 6 cell developer kit package.
The 2500 rated batteries ran even longer.
The battery charger said it takes 9 hours on the 1300 series batteries and 12 hours on the 2500 batteries.
Make sure you charge them long enough, and keep similar rated batteries in the charger.
Don't talk them down for a user unless you tried them.
I think his issue was charging them.
I have a drawer full of AA rechargeables.... really should throw them out... they are crap, but good for those solar powered deck lights...... Hmmm, actually my inMoov eats them like skittles...;) Or maybe you suggest I should replace his 6V 12ah sla battery with a bunch of "aa's?
The ops batteries actually could barely drive one servo... He'll probably buy some Lipos and will be much happier for it...
Let it lie Steve... You really going to "call me out" for dogging on "AA" rechargeable batteries? You use your "AA"s and I'll use my Lipos and SLAs.... everyone is happy...
Watch again the vids powered by AA.
You are so entertaining, creative, and assertive.
I was not putting you down.
I am glad we have you on our forum.
You have created some great EZ Robots!
The OP is definitely experiencing a brownout (voltage sag) resulting in the ez-b resetting.
So, Yes, you can run 2 continuous ezrobot servos with either 6 x NiMH or NiCd 'AA' rechargeable batteries but here are a few things to note:
- Using NiCd batteries with a lower capacity rating is ok because NiCd's can deliver very fast inrush current. Keep in mind though, a lower capacity means that the servos won't run for too long before the batteries need to be recharged again
- When using NiMH batteries they will have to be a little higher in capacity to make up for their slower reaction to inrush current. I use 2300-2500mAhr.
- Mixing capacities (mAhr rating) of any battery type is not advisable as the lowest capacity will be your limiting factor. If your lowest battery is 1300mAhr, it will be the first to run low and it will drop your overall voltage very quickly
- Due to the chemical change inside batteries (i.e. sulphation, crystallization, whiskers, memory effect, etc) over time any battery type will degrade and loose capacity. I have many rechargeable 'AA' batteries that will charge to their full voltage but when used they will go flat very quickly due to being old and having a much lower capacity now.
In this case, I would do just as @Mohamed.r is already doing, I would purchase some new 'AA' rechargeable batteries.
Alternatively, I would also recommend looking at moving up to LiPo batteries, as they are very powerful for their light weight but I'd say definitely work with what you are comfortable with until you are ready to make the leap
the batteries are nimh 1.2 v
the batteries
Those will work for a very simple boxbot. I run one that just has 2 continuous rotation servos and hte camera, and I use 6 Enloop NiMH batteries. But more than a couple of servos and you will get brownouts, and the bot won't run long on those batteries. Maybe 10 minutes of movement.
If there are any hobby shops in your area that deals with R/C planes or cars you may be able to get a LiPo without the shipping costs from EZ-Robot. Any 2S Lipo will work.
Alan