Woot, someone *has* been having fun..

Microprocessor happy as I am, that sounds like a damn impressive piece of work.. I hope it all hangs together under the stress of combat though..

Rick (Moth) has found that theres a lot of difference between making something tick on the bench, and keeping it ticking after a solid pounding in battle while surrounded by electromagnetic storms, power surges and vibration and shock. Thats why a lot of the American builders gave up on the complex IFI systems and went back to standard proven reliable RC gear, even after they released a version II "Battle Hardened" revision..

Dont get me wrong, I think its great that someone is developing systems like this, but if you are going to sell it to builders who have a few more thumbs and few less bit-blitter skills than you do, before its had some serious fight-time, be prepared to spend quite a while debugging other people's bots..

P.S. If you find any better options than the HIP chip for H-Bridge Mosfet control, please let us know.. I'm turning over some ideas for the IBC Mk II in my head at the moment, and would like to get away from the HIPs in future (if possible, I havent heard of a better option yet).

It would be nice to find a driver chip that survives the destruction of the Mosfets more than the HIP does. They're expensive little things and when a mosfet goes, it often takes them out as well.

Congratualations on your development work so far..
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Great minds discuss ideas. Average minds discuss events. Small minds discuss people

thanks

I think most of this will be pretty rugged, but it's about to get some serious testing!

The 433MHz radio stuff isn't going to be much use to most people, but if my receiver and motor control stuff works it could be pretty handy for lower budget robots.
What I plan to do is make up a controller that works with drill FETs and off the shelf relays so people can salvage as much stuff as possible.

I won't be selling stuff to anyone until I'm very sure it works (and that people want it!), but I might give some to people to test for me

I keep thinking maybe I should have just bought a decent radio set, but this is a lot more fun - and has only cost as much as a few PICaxe chips and a couple of $10 RF modules.
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The Engine Whisperer - fixer of things

quote:

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P.S. If you find any better options than the HIP chip for H-Bridge Mosfet control, please let us know.. I'm turning over some ideas for the IBC Mk II in my head at the moment, and would like to get away from the HIPs in future (if possible, I havent heard of a better option yet).

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that looks pretty good

I generally do surface mount stuff, but for this robot stuff I'm doing as much of it through hole as possible for extra strength and ease of servicing - but the modular design allows swapping whole modules rather than trying to fix things between battles.


This morning I built up a receiver board, and then the frustration began!

It wasn't responding to the transmitter at all, and when I put the scope on the signal coming in from the RF module it looked strange. The channel pulses were fine, but it was missing the sync pulse, and the gap in between didn't have sharp edges. The signal was sort of floating.
After prodding all kinds of things and pulling the transmitter apart to verify that it was sending the right stuff I adjusted the fine tuning on the RF module.
That got the sync pulse back, but the whole signal was inverted!!
After more tweaking I managed to get the signal showing up properly, but every now and then it'd turn to static.

So, out with the high quality expensive RF modules, and in with the cheapo Jaycar ones that don't have a tuning adjustment

Once it was working nicely I tried out the hardware failsafe, which actually works really well, but I'm using the wrong transistor for the job so I need to get the right one (2N7000 MOSFET).
At the moment it works, but while at full output the failsafe sags and the PWM signal into the opto board can be lost.
A bit of playing with component values should be all that's needed.

I loaded in the software for the DDR version of the receiver, plugged a servo in, and it works!
I get PWM / direction signals, and a steering servo drive out of the one 17x29mm board!
I haven't built up the FET and relay driver board yet, but I've tested things out using my other FET board, which does seem to work ok.

Edit: the hardware failsafe works with the new FET in it
I can change component values for different timeouts, but at the moment it kills the outputs in about a quarter of a second after the transmitter is turned off.
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The Engine Whisperer - fixer of things

**Puts his name down for BETA testing**
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https://www.halfdonethings.com/

XD ditto
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( •_•)

( •_•)>⌐■-■

(⌐■_■)

YEAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAH

I've been having to build work stuff at work so my progress has been a bit slow!

Tonight I did a few tests though, and the control seems to be nice and reliable from the other end of the house, which is nice
I was having trouble with the FET board oscillating when driving big motors without any noise suppression, which is no real surprise.
When I next get a chance I'll do a proper FET board design and test that out.

I'm going to do another control unit, which people may be interested in.
The plan is to make some ultra simple but (hopefully) reliable controller modules that can be used for either weapon control or drive channels.

They won't be variable speed, but will drive any size relays or small motors directly.
Each module will be one channel, and give forward and reverse outputs to drive mainly relays.
The boards will be able to gang together and will do mixing - so with two boards proper mixed tank control can be done on a very low budget.
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The Engine Whisperer - fixer of things

quote:

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Originally posted by TDT:
I found the TD340 fet driver a few weeks back and hav been eyeing it for possible ideas of driving fet bricks.

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hmm, that is a good point

I'm trying as much as possible to build all my stuff out of things that can be bought from Jaycar anyway, so I'd have needed a pretty good reason to use those chips!

Most of my FET stuff has been low side only, so that's pretty easy to drive using optos, etc.
Maybe it's worth doing a beefy fet driver with discrete components?
There's still the issue of high side drive voltage, but there are various boost chips out there.
It could even be done with an RS232 driver keeping a large cap topped up since the FET drive is only going to require very short bursts of high current.
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The Engine Whisperer - fixer of things

ok Stealth is getting custom controls, whether it works or not!

The new FET boards seem to work, and will hopefully handle the current needed. Later on I'll upgrade them, but for now they should do the job.

Stealth will have three processors onboard!

I have some basic relay controllers working now too, and they'll be going in Speedbump for some battle testing
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The Engine Whisperer - fixer of things

w00t, Tri-Core Processing
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https://www.halfdonethings.com/