Turnigy TZ-85A brushed motor hack - amended code for Spektrum Dx6i

[Danjr1]

Hi all,

Following on from the amazingly brilliant open source code created by Aaron Knight and Steve Martin at Botbitz to convert Turnigy TZ85a ESCs from brushless to brushed motor controllers that a load of us have used, a few of us have experienced issues using this code relating to the Spektrum DX6i's internal mixing when measures are implemented to facilitate 100% throws in all directions as opposed to the stock elevon function that only allows 50% travel in the forward and backwards directions. This is due to this mixing set-up causing the RC signal to go above 100% which causes the hacked ESCs to failsafe. There have also been issues with the temperature limit kicking in too early and failsafeing robots as well.

With a massive amount of help and guidance from Kane, John from Team Beast and advice from Aaron and Steve on the robowars forums relating to the temperature limit problems, i've been able to adjust their open source code slightly to compensate for the DX6i's weird mixing and turn off the temperature limit. This code is attached below. Using the botbitz tutorial to install the code, both Team Beast and I have tested the code and it worked for us but if you intend to download, install and use it, this will be at your own risk and I take no responsibility for any damage caused by its implementation. I also cannot guarantee that this code will work for you either. Below are the two set-ups that its been tested on so far:

My set-up: DX6i, Orange Rx 620, two ESCs running four gimson 18v 24:1 gearmotors on 6s
Team Beast set-up: DX6i, Spektrum BR6000, two ESCs running two speed 900s on 6s

I would like to take this chance to really thank Kane, John, Aaron and Steve for all their help in solving this problem as its really been bugging me for a long time, and especially thank Aaron and Steve for creating the code in the first place. Below are some links relating to the TZ85a hack:

The original how to hack and program TZ85a tutorial by Aaron and Steve at Botbitz: http://robowars.org/forum/viewtopic.php?t=1609
How to hack video from Aaron and Steve at Botbitz: http://www.youtube.com/watch?v=EAKYSyOx75Q
How to program video from Aaron and Steve at Botbitz: http://www.youtube.com/watch?v=i1-bWNeuAqA
DX6i full servo throws video: http://www.youtube.com/watch?v=6Ewa79_9Iq4

BrushedESCdx6iorangerx.hex.zip

[shakesc]

Thanks for this. Looking forward to trying it out

Chris

[PJ-27]

Thanks for all YOUR effort Dan.

[shakesc]

Programmed up 3 TZ85 with the new code.
This fixes the >100% mixing problem of the old code. Havent been able to do a test drive, just a bench run but this is going to make the bot alot more controllable. Thanks again

[Danjr1]

Did some more testing today and all worked well on my set-up!

[Dan-27]

I re-programmed my ESC's with this code and they worked really well.

I've used them in my uni project, here's some footage of it driving around.

http://www.youtube.com/watch?v=HOUYbgvVgAs

[Eventorizon]

How easy is it to do a reprogram and what effect would it have on switching to other transmitters?

We have 6 TZ85A's and both run DX6i's but I was thinking that it would be easier to go up to a DX7 or drop down to a DX4 just to solve the issue permanently.

Could we post them to someone as well to have them reprogrammed?

[typhoon_driver]

Reprogramming them is easy. Just buy the pololu programmer, solder a few connections on the board, install software on your pc and then hit a button and it's done.

If I was to reprogram for you I'd want something for my time. TBH you'd be best learning to do it yourself as it's not difficult

[Danjr1]

It's really not that hard at all, can be a little daunting at first though. If your ESCs at the genuine botbitz ones, you'll need to solder a new wire to the B port as they will have removed that and the open source code uses it. Team beast had the same problem with a dx7 so buying a new spektrum Tx probably wouldn't work.

[Eventorizon]

Thanks guys.

Yeah, they are Botbitz ones. It will just save us a ton in time and money if we can get it working as we can hack our own from scratch too.

[beast]

just an update tried to blow it up today just wheels spins and does not stop its pretty cool now testing at Guilford on Sunday

ps itd an old dx6 not an I ok

[typhoon_driver]

I have stalled a drill out on them. You will struggle to blow one with a feather.

[Ellis]

I've stalled a drill (with a second often on a dodgy gearbox) on them in almost every fight, they never even get warm.

[beast]

don't worry with johnno and Alan driving they will get warm with speed 900s (better do or we are out lol)

[Max]

A quick question to those that have reprogrammed these escs- I am looking at having to reprogram quite a lot of these controllers (possibly 20 for 10 robots), what I wondered was would it be fairly simple to make up a jig so I placed the controller on the jig which had littles wires poking out in the right positions to make contact with the reprogramming pins to save me having to do a load of soldering? Or does it need the extra wires to remain in place once reprogrammed?