TinyTwo Speed Controllers

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Rapidrory
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Re: TinyTwo Speed Controllers

Post by Rapidrory »

I've got the fet buffers, also need CMOS hex inverter chip on there as you need some protection logic on the high voltage side... It would have made design and construction much easier however if it were all in one chip :L

Well I haven't managed to get them to heat up significantly yet, though that is with them only driving half an amp so that's not saying much... And yeah, i always take datasheet values with a pinch of salt...

Having to wait till Monday until I can do anything more; I accidentally shorted the 5V and motor power rails whilst testing it at 12V and fried both the PIC and my Rx -.- I have spares of both, but need to get use of the uni labs to solder in a new PIC...

Out of curiosity, anyone know the rules for selling this sort of thing on Ebay? I can't see it being a problem as long as you had the relevant disclaimers...
Rory Mangles - Team Nuts

Robots: Nuts 2 and many more...

NanoTwo Motor Controllers: https://nutsandbots.co.uk/product/nanotwodualesc

shakesc
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Re: TinyTwo Speed Controllers

Post by shakesc »

Rory

looks good, I'd be interested in purchasing

Chris
I started out with nothing and still have most of it left

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peterwaller
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Re: TinyTwo Speed Controllers

Post by peterwaller »

That explains why I didn't find it before I only considered full motor drive chips with all the control logic built in to make life easier. :roll:
I will be interested to see how you make the connections to the boards I am a fan of making them fully pluggable but I know others prefer them all soldered in.

Rapidrory
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Re: TinyTwo Speed Controllers

Post by Rapidrory »

Yeah, when I originally found and bought the chip i didn't realize that it'd need all the extra hardware untill i put one in a test rig on breadboard :L

I've since found some servo driver chips of the same size, but with all the required logic in them. They were only 1.8A output, but that should be fine for a 2WD robot. Unfortunately, the only data sheet I could find was in Chinese, and I could find no where that sold them. They'd be good though cause you could probably make a dual ESC almost half the size of mine with them! Might have another look some day..

Yeah, i'm not entirely sure how i'm gonna do it myself on the commercial ones; for the prototypes, i'm just soldering all the wires straight to the board :L
Rory Mangles - Team Nuts

Robots: Nuts 2 and many more...

NanoTwo Motor Controllers: https://nutsandbots.co.uk/product/nanotwodualesc

Hogi
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Re: TinyTwo Speed Controllers

Post by Hogi »

any idea on the cost of one of these boards? i might be in a position to start a new ant project around easter time and i was hoping to do either a fan pusher or 4WD pusher. also, what size and weight are they? i'm a complete novice builder so I need all the room and weight i can get. :D
Daniel Jackson.

Team Hectic.

Many antweights

Super antweights: territorial.

Fleaweights: fleadom fighter, gaztons.

Featherweights: hectic (under construction)

Rapidrory
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Re: TinyTwo Speed Controllers

Post by Rapidrory »

They'll probably be selling for somewhere around £30, which i know isn't remarkably cheap, but they're not the quickest or easiest things to build :L

The boards are currently 21x21x6mm, although that may change slightly as there's a few routing errors in the prototypes, which when fixed may change the dimensions of the board slightly..

They probably won't be ready for sale for a month or two yet, as they still need a fair bit of work, and my degree has a habit of getting in the way of my projects :P
Rory Mangles - Team Nuts

Robots: Nuts 2 and many more...

NanoTwo Motor Controllers: https://nutsandbots.co.uk/product/nanotwodualesc

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BeligerAnt
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Re: TinyTwo Speed Controllers

Post by BeligerAnt »

Selling stuff via Ebay is no different to offering it for sale via any other channel. Any electronic devices placed on the market in the EU have to be CE marked and comply with all relevent CE-marking directives. The Low Voltage directive may not apply, but the EMC and RoHS directives certainly will. Whilst it may be feasible (if immensely tedious) to comply with the current RoHS directive, complying with the EMC directive is very expensive as well as time consuming.

These directives are not optional and there are very few ways of avoiding them. Applying the CE mark is a legal declaration of compliance that you have to be able to back up in a court of law - you require evidence that you comply.

As far as I know electronics kits are still exempt at least from the EMC directive, but you would have to work out how much assembly constitutes a "kit" rather than a product. And ensure that the exemption is still in place!
Gary, Team BeligerAnt

Rapidrory
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Re: TinyTwo Speed Controllers

Post by Rapidrory »

Yeah ok that all sounds far too much like hard work :L

I only ask really as a friend is looking to sell one of his projects (nothing to do with robots :L) and hadn't looked into the legalities till i mentioned it.. Plus if it wasn't a problem then I might have stuck a few of my boards on there just for ease of handling the transactions, but ah well :L
Rory Mangles - Team Nuts

Robots: Nuts 2 and many more...

NanoTwo Motor Controllers: https://nutsandbots.co.uk/product/nanotwodualesc

Rapidrory
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Re: TinyTwo Speed Controllers

Post by Rapidrory »

Ok, got the second prototype up and running now without too much trouble; at least I now know it's repeatable :L

BTW, If I were to build another controller with only 1.2A continuous per channel (2.5A peak) at a max of 10V, do you think that'd have enough headroom to run a 2WD 2 cell ant reliably? I only ask cause if so, I should be able to build another much cheaper board for smaller ants with dimensions of somewhere around 13mm x 13mm without too much effort... (Infact already have the first draft of the board layout... 1 hour instead of almost 100! :L) *EDIT* tried out the 1.2A driver, and it ran both the motors in Tinny wired in parallel fine, and only heated slightly when stalled :) Gonna go ahead with the NanoTwo board as well now. They share most of the components with the TinyTwo, which makes life easier.

Also, I know there's rules about making your own receivers... but if I were to use a receiver chip, which only required a few parts to handle the RF side, to make an all-in-one ant-weight board, would that be pushing it? :L
Rory Mangles - Team Nuts

Robots: Nuts 2 and many more...

NanoTwo Motor Controllers: https://nutsandbots.co.uk/product/nanotwodualesc

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BeligerAnt
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Re: TinyTwo Speed Controllers

Post by BeligerAnt »

If you are thinking of using the TB6612 driver chip, I would have to advise against it. They don't (quite) handle antweight motors running on 2-cell LiPos. They seem OK for a while, but I had one fail after a long day at MakerFaire. I think they're a bit marginal, especially for the HP motors.

There's nothing to stop you from building a radio receiver (transmitters are another matter) but it's not an easy job. Laying out microwave circuits is nothing like "normal" PCB layout. Unless you really want to get into RF design (the hard way!) I would suggest buying a receiver like the Deltang RX31 http://www.deltang.co.uk/rx31b.htm and integrating it onto your board as a module.

I'm not trying to put you off, but sometimes it's really not worth the effort!
Gary, Team BeligerAnt

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