Yet Another Antweight Speed Controller

All things antweight

Moderators: BeligerAnt, petec, administrator

User avatar
BeligerAnt
Posts: 1872
Joined: Wed May 15, 2002 12:00 am
Location: Brighton
Contact:

Yet Another Antweight Speed Controller

Post by BeligerAnt »

After a weekend of coding I have a functional speed controller. Yet another contribution to the recent rash of antweight ESCs :)

My project is based on the ideas of Steve Martin (marto) on the Australian RoboWars forum, which culminated in the BotBitz range of ESCs - brushless ESCs reprogrammed to drive brushed motors. However, I have written the code from scratch and will make it available under the BSD open source licence. The code will be hosted on Github to encourage collaborative development, so if you are interested in contributing to the project keep an eye on this thread.

Currently the code is written to work on the HobbyWing 6A brushless ESC available from GiantShark for about £7. (Sadly they have gone up since I bought a couple a few weeks ago - a real bargain at £5). Now I have the basic code working I plan to re-structure it to make it much more flexible and easily adapable to other brushless ESCs that use the popular Silicon Laboratories 8051F330 microcontroller. (Hobbyking 6A and 10A are likely first candidates.)

I plan to have a pair of these boards in RONNY at AWS43. Assuming they perform OK I will work on the documentation necessary to share the code and put it all on Github.

For anyone interested in reprogramming brushless ESCs, a programmer can easily be built from an Arduino. It may be possible to use a Baby Orangutan, but since the clock speed is different it may not work. Details and all the software can be found here: http://www.olliw.eu/2012/owsilprog/
Gary, Team BeligerAnt
Rapidrory
Posts: 1160
Joined: Sun Nov 24, 2013 9:54 pm

Re: Yet Another Antweight Speed Controller

Post by Rapidrory »

Ah, very nice solution!
Yeah, classic case of waiting for something to come along, then two arrive at once :P Hopefully our ESC's are different enough not to kill the market; I've just bought about £100 worth parts to start work on the first batch :L Do the reprogrammed brushless ESCs retain their original current rating? If so 6 Amps is pretty impressive!
Rory Mangles - Team Nuts

Robots: Nuts 2 and many more...

NanoTwo Motor Controllers: https://nutsandbots.co.uk/product/nanotwodualesc
User avatar
peterwaller
Posts: 3213
Joined: Fri Feb 15, 2002 12:00 am
Location: Aylesbury Bucks
Contact:

Re: Yet Another Antweight Speed Controller

Post by peterwaller »

Looking good Gary the best things about this approach are that not only is the hardware readily available and cheap but people will learn quite a lot by going through the process.
Perhaps you could offer a conversion service for those who feel that they are not quite up to it.
I look forward to seeing it at the AWS which I notice you are not yet signed up for.
The way things are progressing I might be able to retire from the controller building game at some time in the not too distant future. :wink:
haz
Posts: 1855
Joined: Thu Apr 15, 2010 11:20 am
Location: Underwater Lair
Contact:

Re: Yet Another Antweight Speed Controller

Post by haz »

As someone who uses those hacked 6a controllers and was sad to see them stop being sold from botbitz I'm very happy to see this :)
User avatar
earthwormjim
Posts: 1190
Joined: Thu Sep 16, 2010 4:57 pm
Location: Secret Undisclosed Moonbase Location

Re: Yet Another Antweight Speed Controller

Post by earthwormjim »

Yay! Right up my street!

Just recieved an Ardurino starter kit this morning, by weird coincidence!! :o
Image
User avatar
BeligerAnt
Posts: 1872
Joined: Wed May 15, 2002 12:00 am
Location: Brighton
Contact:

Re: Yet Another Antweight Speed Controller

Post by BeligerAnt »

Rory: Different strokes for different folks, I don't think one design will really dominate.
Peter: Point taken, I've been too busy coding to sign up :P We will be there though :) And we don't want to let you retire yet!
Haz: I don't suppose it's anything to do with licensing issues? The difference here is that this is a collaborative open-source project rather than a commercial undertaking. I will *not* be offering re-programmed boards for sale.
Jim: Have fun with the Arduino, and keep it handy to turn into an ESC programmer!
Gary, Team BeligerAnt
haz
Posts: 1855
Joined: Thu Apr 15, 2010 11:20 am
Location: Underwater Lair
Contact:

Re: Yet Another Antweight Speed Controller

Post by haz »

No it was because no one bought them, or rather that the 10a ones outsold them massively. I'm not too sure though.
Andrew_Hibberd
Posts: 1134
Joined: Tue Jan 20, 2004 12:00 am
Location: London
Contact:

Re: Yet Another Antweight Speed Controller

Post by Andrew_Hibberd »

I understand how a brushless esc can give full power forward and back but is it limited to 50% voltage when turning? As the middle cable has to give +ve one way and -ve the other @ 50% duty.

I have been playing with flashing brushless escs this week, I bought one of these for my fan robot and wished I didn't as it was terrible: http://www.hobbyking.com/hobbyking/stor ... _2_4S.html. Reading the comments I tried flashing it with SimonK kda.hex, it gives the right beeps but still doesn't spin. So got a different make coming, hopefully by Friday.
TEAM GEEK!
marto
Posts: 25
Joined: Thu Sep 15, 2011 1:05 pm

Re: Yet Another Antweight Speed Controller

Post by marto »

Code to do this has been freely available since end of 2011. So I wouldn't expect a bunch of people to start programming them. And not one person ever contributed to my open source development so goodluck with that too. Also I spent maybe 100hrs helping people program their own avr version ones with very little thanks and in the end just got sick of everyone expecting me to drop everything to help them fix their ESC programming issues 2 days before an event having never programmed anything in their life before. Oh also if it fails because they short it, put too big a motor on it, screw up programming or get a dodgy one from hobby store. That's your fault too.

Not everyone is like this it's just what you remember and what wears on you supporting an open source project. BotBitz was not an effort to make a bunch of money it was just an easier way and I actually think it's more worthwhile. Could almost class it as NFPO as all the cash gets reinvested in development and events.

As for the 6A they were more expensive, harder to program, less reliable and I think we sold about 8 in 2yrs so it wasn't really a big move to can them from store.

As for 50% that is only if you drive two motors off one ESC. And yes there is huge variability, between ESCs even if they look identical.

Steve
knightrous
Posts: 77
Joined: Tue Jan 19, 2010 8:29 am
Location: Australia

Re: Yet Another Antweight Speed Controller

Post by knightrous »

As Steve said about the Open Source Code that was published in 2011 (https://launchpad.net/brushed), he even included a step by step video on hacking the 85A controllers, yet only a couple of people actually did it. BotBitz sorta formed after people complained that it was still too hard (or they were too lazy, which includes me... :P)
marto wrote:As for the 6A they were more expensive, harder to program, less reliable and I think we sold about 8 in 2yrs so it wasn't really a big move to can them from store.
We sold 31 since September 2012, while in the same time period we sold 376 of the 10A's....
Antweights: Scarlet

BotBitz - Antweight, Beetleweight & Featherweight parts at an affordable price.
Post Reply