Is there something a guy can do that will stop the tank from restarting once it has been killed. I suppose the problem is any signal that kills the tank would also kill the" Destroy sound". Any thoughts on this?????

I'd like to see an option for a cut out relay like Tankhobby has with his system. The RC2HL 'should' allow you to switch off the tx and tank as the death sound is playing by switching channel 5, but I'm having mixed sucess with that so far - I'd rather have the auto cut-out than rely on timing the switch-flip or 'player honesty' to shut it down

Just my suggestion... [8D]

Hrm. As it stands now, not easily. The RC2HL has the switch flip option in 5-chan mode, though you do have to flip it before or after the TK-RX1x board begins startup (it ignores the switch during startup to try and prevent an "out-of-sync" condition.
Auto-shutoff like the Tamiya units can be iffy if your radio signal isn't good (and the TK-RX1x board takes longer to startup than the DMD/MF), plus it doesn't work with PCM/2.4ghz radios.

I had thought about allowing the user to shutdown the TK-RX board *and* DBC using the key button, but it's tricky, as the DBC has no way of knowing if the TK-RX board is on or off, so it's virtually impossible to keep the two in sync perfectly. I suppose I could at least modify the DBC-HL to not accept hits when the radio is off. That way you could shutdown the TK-RX board, then turn off the radio to disable battling. Only issue might be if the RX then becomes susceptible to noise, which could randomly startup the tank and start driving it! :P
I'll have to take a look and see if I can fit it in, as the PIC is pretty much full right now.

And if you can't trust the other players...I don't know if there's much point in playing with them. They could be spraying the inside of their TBU/DBU with dullcoat on the mirror...added a more powerful IR LED, etc. That said, you could tap the destroy sound output on the RC2HL to drive a FET, which would drive a latching relay to shutoff the tank. As YHR said, you might need a 555 timer in there to delay it enough so that the sound would finish.

D.

I agree that your current systems probably won't accomodate my request as they are - for one thing, Tankhobby's system doesn't interact with the ESC and draws power from the battery directly. Your idea of using the sound output to trigger an external circuit and relay was kind of what I had in mind, but I was thinking how about detecting the end of the long signal to the LED's on the DBU when the tank dies - does this last as long as the death sound plays?

'Player Honesty' was probably a bad choice of phrase: I was thinking about having to explain how and why the tank needs to be shut down when the "lights on top come on and stay on" to some of my friends' children, and then getting them to do it at the right time... [sm=confused_smile.gif][sm=drowning.gif]
Compared with that, asking for a relay circuit to be added is easy... [sm=biggrin.gif]

(edited for bad proof reading...)

The LEDs are lit up for the 15 seconds the tank is dead and while it's starting up again. The death sound is triggered at the beginning of this time, but can last as short or as long as the recorded sound is.
It would be possible to detect the longer period while the LEDs are lit, but not in a super simple fashion. I'd probably tack on a micro controller if I was doing it, or start a 555 timer when the LEDs are lit, and trip a relay when it finishes *if* the LEDs are still lit.

Ahhh...kids. Well, that's different.

I'll have to think about it a bit.

D.

"High school" (aka GCSE for our English viewers) electronics classes were almost 20 years ago for me and I studied mechanical engineering at Uni, so please don't think I actually know what I'm talking about when I make these requests
I was thinking that maybe you could connect a capacitor to the LED output and have it charge a little everytime that the LED's came on, and when the final hit came it discharged and triggered the cut out relay. The problem with that bright idea is that I suspect the wide range of hits allowed for the various classes means that the super light weight wouldn't fill the capacitor before it was supposed to be dead, and the Heavy class would trigger before it took all the hits it was supposed to?
(or is my recollection of those classes and how capacitors work getting a little too fuzzy? [] )

Mmm, not a bad idea. I think a better idea would be a large capacitor charging from the LED output with a variable limiting resistor, and a very high resistance bleed resistor to discharge it when the LEDs are off.
Then, the LEDs would charge the capacitor until it reached a high enough voltage to trigger a transistor which drives the shutoff relay.
Trim the limiting resistor so that the short ~1 s flash from a hit doesn't charge it very much (and the bleed resistor will discharge the cap so it doesn't build up from multiple hits), but that the longer ~15s lit period when dead *does* trigger it. This way it would be independent of the number of hits required, and the period between the hits shouldn't matter. (If you tried to accumulate hits, the internal leakage of the cap might allow it to discharge between spaced out hits).

It still *may* be finicky, as heat will change the resistance of the limit and bleed resistor. Might also need to use good tolerance components if you wanted to build more than one, though the adjustable limiting resistor should help tune it.

Worth a shot I think. But my analog design sucks...so I'm not sure of the component values to start with.

R1 is the adjustable charge timer.
R2 is the bleed resistor. Would need to be big enough that the cap can charge within a reasonable period of time, but small enough that it discharges reasonably quickly.
Note that the LED+ is directly connected, and LED- is switched on the DBC. It might be easier to connect to the PIC chip before it drives the BS170 fet that drives the LEDs, as that pin is driven positive.

D.

Darkith,

What keeps the cap from discharging through the LED when LED drive is removed??

It would discharge back through there, but it should be pretty slow, as the voltage should be pretty low (and once it gets somewhat high, it will discharge through the gate of the transistor). Discharging through the LED wouldn't really matter (unless it left the LEDs on for a while, which I don't think it should). You really just want it to take time to charge up while the LEDs are on, so the transistor doesn't conduct until say 5secs or more have passed.

If it was on the LED side of the LED FET, it might keep the LEDs lit and fade them out slowly, depending on the values of the R1 and R2. Juggling R1 and R2 should limit that period I think.
If it was on the PIC side of the LED FET, the PIC drives the line low, so any current from the cap should drain directly without driving the FET. R1 should keep the cap from damaging the PIC with high current.

A diode would always prevent backwards discharge if needed, and may be a nice simple solution. Like I said, my analog sucks, so it may need tweaking.

The schematic is really designed to go on the PIC side of the LED FET, just tap the middle pin of the LED FET. You'd have to flip things around for the LED side of the FET, as the FET switches LED-, which could make things a little trickier.

D.

Darkith,

Your analog is pretty good. I think you nailed it.