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mikep

Combat R/C Module

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Just to let you know I started building the combat R/C module.

I designed a PCB for it and will make them tonight. I also ordered all the parts from Digikey (enough to make 10 of them) wich should arrive tomorrow and already have a couple of the Hobbico Modules.

So hopefully by the weekend it will be all done and ready.

Now I'm trying to convince a few of the guys at the club to buy some Hobbico Modules.

Thanks for sharing it!

Mike

P.S. I'll let you know how it goes after my first dogfight.

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Please let us know how it goes. Most of the feedback I have gotten has indicated that sonic combat is difficult but a lot of fun.

Are you building the simple version or the AWS model? The latter is the ideal choice (the hit counter is a nice touch).

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Yes I'm building revision 2.

Anyways here's my problem. I built the PCBs basically to only work with the aux ch. attached. This should not be a problem however. It is needed top get the 5V+ to the R3 and the LED as well as Pin 4 of the command module.

When I turn on the receiver I get the beeps and the yellow LED comes on.

The throttle servo is working fine through the PIC. A bit of movement near the very top and bottom of the control but I can live with that.

However when I go to fire (using the aux channel which I have on ch. 5 of the receiver) it will only do so when the throttle is at max (or just about).

Below that it doesn't fire (make the chirping sound for 1 second).

Any ideas?

post-6-1064525564_thumb.jpg

Edited by mikep

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(1) Despite the problem, when a hit is detected, does the throttle pulse on and off for a few seconds?

(2) If it is installed on a e-model, does the cannon fire correctly, at all throttle speeds, if the motor is disconnected?

(3) If you install the AWS's Aux channel into the other R/C channels (rud, elev, ailer, etc.), can you find a combo that allows firing throughout all throttle settings?

(4) If you use it in the throttle only mode, does it work? That is, if the Aux channel is disconnected, does the cannon fire correctly? At what throttle position does it fire? How low do you have to go to successfully re-Spam Spam Spam the weapon?

(5) What Tx and Rx are you using?

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(1) Despite the problem, when a hit is detected, does the throttle pulse on and off for a few seconds?

Not sure since I haven't built the second one yet. I didn't want to waste parts if there's a problem. But if needed I could.

(2) If it is installed on a e-model, does the cannon fire correctly, at all throttle speeds, if the motor is disconnected?

Right now I'm only bench testing. So I have ch. 3 connected (throttle), ch. 5 (the aux) and one servo plugged into your module. As well as the combat module naturally and the battery.

(3) If you install the AWS's Aux channel into the other R/C channels (rud, elev, ailer, etc.), can you find a combo that allows firing throughout all throttle settings?

Yes it seems to work ok on ch. 1 & 2. So I guess it is something to do with the radio.

(4) If you use it in the throttle only mode, does it work? That is, if the Aux channel is disconnected, does the cannon fire correctly? At what throttle position does it fire? How low do you have to go to successfully re-Spam Spam Spam the weapon?

I can't do that because of the power issue. If I don't have the aux ch. plugged in the combat module doesn't get power.

(5) What Tx and Rx are you using?

I'm using a Futaba T6XH for testing with a regular PPM 7 channel receiver.

I will be using a Futaba 9C with hopefully a PCM receiver but I understand that might not work with that.

I'm still confused about why it would fire with the throttle up and not anywhere else. I looked at mixes on the radio and it looks like all is inhibited. But I don't really remember all the programming options on that radio. I only use it for testing stuff. Let me get the 9C out and see how things go with that.

Thanks for the help!

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What happens if you reverse the throttle via the Tx's setup features?

I can't do that because of the power issue. If I don't have the aux ch. plugged in the combat module doesn't get power.

Can you add a jumper wire to accomodate that test?

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OK well for some un-explained reason it does not like the Aux channel to be on channel 5. When I changed to my 9C radio it did the same thing.

As soon as I assigned my fire button to channel 6 instead (or any other channel) it worked fine.

I then tried it on a PCM receiver and same thing. No go on 5, everything else was fine.

So now I will make the other one and test it out on a plane tomorrow.

I'm wondering if the nose gear and the propeller arc will interfere with it?

Here are some pics of the finished module before I heat shrink it.

Oh when I reverse the throttle it's the same thing but opposite. Fires when throttle is all the way down but nowhere else. It's pretty hard to jump wires right now. I epoxied the side of the components so no wires can ever shake loose and sprayed conformal coating on the trace side. I guess I jumped the gun a bit on those. It also makes it hard to probe for debugging! :-)

post-6-1064531748_thumb.jpg

Edited by mikep

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Mike, based on your comments, I just spent some quality time with the PIC code and the emulator.

I believe that a timing problem exists with the Futaba. The position of the throttle channel in the PPM stream seams to impact the AWS system. PM me with your email address and I will send the revised hex file for you to try. I think it will take care of your issue (if my assumptions are correct).

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My ears are still ringing...... (wear ear plugs while testing)

First of course I can't re-program the chips I already used. :-(

I knew that, but tried just the same. I should have ordered a couple of spares!

But YES it does work on ch. 5 now.

On the bench, everything looks great.

I will try it at the field later on today and let you know how that goes tonight.

I better start marking the versions on the chips before I get them mixed up. Luckily I only burnt 2 of them. I almost burnt all 10 at once.

Cheers,

Mike

P.S. What's this "Newbie Stage Hand" stuff. I've been posting on your board for ever now! :-)

Edited by mikep

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Mike, that is great that the new firmware works on your channel 5. Does the hit counter work for you too?

If you have time, can you also confirm that the throttle only method works with your Tx's? I do understand that your board layout will require a temporary jumper to try that.

Don't burn all your chips yet. As soon as you confirm that all the features work I will release the final updated version (I will remove my debug code from the compiled work). Also, I think I can provide better compatibility for PCM Rx's (with luck). I will email the final version to you after you are done testing the version sent to you last night.

Note: You can certainly use the existing revised code on the chips you just programmed. But, try to wait for my final version for the remaining blank PICs.

Newbie stage hand: On this new board, we all start out as Newbie's. Even me. Keep posting and you will soon be a gaffer. ;)

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Yes the hit counters work fine.

The 2 boards I completed are hard to jump, but I still have 16 other boards to play with. I will drill them and solder them this weekend or monday and let you know about the throttle firing.

I went out today to play with them and here are my initial observations.

When simply holding the modules in my hands I seem to be getting a range of about 80 feet, which is as advertised for these modules.

However once I mounted one on a plane (the other was left on the ground) the range seemed to be reduced to about 20 feet. I tried both while taxiing and fly overs. The propeller and my landing gear were somewhat in the way however. I have the module mounted below my main landing gear on a .40 size trainer. Also I'm wondering if having the module one the ground also did not help. I noticed with Hobby Zones target they have it mounted on a stick.

I also wanted to try it in the air plane to plane, but could not find anyone to fight with me today (bunch of wimps!). Hopefully this weekend.

I'm also thinking about placing the unit below a wing to avoid the propeller arc and the landing gear to see if this will help the range. Perhaps even having 2 modules, one on each wing.

I'll let you all know how it goes!

Edited by mikep

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As you know, the sonic modules are acoustical devices. But, the actual trigger frequency is not what you hear. Instead, it is some harmonics that are at 40Khz. In other words, what you hear is for effect only.

The cannon's piezo speaker is driven at 60VAC Pk-Pk to get the necessary (and painful) volume. As you say, work bench ear protection is wise.

Due to the high frequency the audio is very directional, which is a good thing (more like firing a real weapon). The speaker is seen in the embossed region on the bottom of the cannon and the mics are fore/aft. You can observe this layout to aim your cannon in whatever direction seems to be best for you and your combat style.

And since it is acoustical, competing noise and vibration from your model will impact range. Keep the module away from the noisy e-motor & prop area. Try balancing the prop to reduce mic vibrations (they cannot be heard, but they reduce the mics' effective dynamic range).

I think that a range of 20 feet in the air is a decent scale distance. Think of this as WW1 or WW2 dog fighting instead of computer guided armaments. ;)

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I think that a range of 20 feet in the air is a decent scale distance. Think of this as WW1 or WW2 dog fighting instead of computer guided armaments. ;)

I can see alot of mid air crashes at 20 feet. Especially if you get a hit... one plane flying at full throttle the one in front gets hit and starts to sputter. CRACK!

I knew the piezo was on the bottom (from trying to cover it up while testing on the bench) but I thought it was only used for signaling a fire and a hit.

For some reason I thought that the part in front was a speaker and the one in back a mic. I have not opened them up yet. Will do that soon.

I did notice that when I went over one module with a plane running in my hands it went off. I guess my engine was hitting that 40Khz range.

Seems kind of silly to have it pointing down. So basically the idea would be to be above your opponent and then fire.

I wonder how hard it is to make my own modules.

Edited by mikep

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I can see alot of mid air crashes at 20 feet.
As I have discovered, it is impossible to hit another model if you try. I tried U-Control combat years ago and it was a tough contest to win at. On the other hand, when you don't want to hit the other model is when mishaps occur.

I'm thinking that a couple of slow flying models (SlowSticks) would be ideal for this combat fun. And relatively safe.

For some reason I thought that the part in front was a speaker and the one in back a mic.
That is quite possible. If you take a closer look please report what you find. I lent out my combat modules so I cannot recheck the two elements out. However, my tests did seem to indicate that the loud piezo alert was the only sonic emitter (muffling it reduced the range).

I wonder how hard it is to make my own modules.
I'm going to have to say that it is harder than it would appear. Frankly, these $25 modules are a very good deal.

If you want more range, just hack what you have. Try moving the existing xdcrs to more optimum areas. Extending them outside the case would get them onto the wings or tail for better aiming. Some 30AWG Kynar wire (twisted pair) would be perfect.

But before you do anything, try the stock system out. I understand part of the fun is because it takes some skill and practice to get a hit. I really have no idea though -- I created this project for others to enjoy. I'm just a happy spectator.

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I really wanted to get to bed early tonight, but my curiosity got the better of me.

So I took the Hobby Zone Module apart.

And as I thought there is a 40Khz transmitter in front and a 40Khz receiver in back.

The piezo is there only for notification.

The part numbers I read are:

CSR40-12P

234S

And

ST40-12SP

317S

I have a feeling that is really CST40-12SP and I am missing the C.

This would be the "R" for receiver and the "T" for transmitter.

I did some web searching but came up with nothing.

If anyone knows who manufactures these I would love to find out.

Cheers,

Mike

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That is good info.

It's not clear to me if this is what you are after, but if you are interested in buying some ultrasonic transducers then you can get them from Digi-Key and such. Electronic Goldmine and other surplus stores carry them too. Just look for those with a 40Khz center frequency and a few Khz bandwidth.

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There's also a ton of circuitry in there. Mostly all surface mount. The 2 chips on the board have had their markings removed.

I will post a picture later.

Really all I was looking for now were the datasheets of these parts. Was curious about db levels, patterns etc.

Now if we started getting serious about combat at my club using these modules then perhaps I would line the leading edge of my wings with transmitters!

Kind of like on a Corsair :-)

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Mikep, have you had time to finish validating the new AWS firmware with your Futaba gear?

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Sorry got stuck on other things. But I thought about it I will just hook up the + and - pins and leave out the PW pin. That way I don;t have to solder another board. I'll do it tomorrow.

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OK I tested it out this morning and seems to work fine.

I only tested it with one unit, but it fires on cue!

My other unit has been loaned out to be placed in a GWS spitfire.

6 of these will be going in GWS ME-109s and Spits for an electric combat squadron.

Cheers,

Mike

post-7-1065012001_thumb.jpg

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