[Alexk]

Considering that the complete TCB will probbably not be available for purchase for the coming time, I would like your advice on acquiring the TCB.

At this moment I have considered two options:

1. buying a unpopulated PCB(via OSH, china or a local company) and populating it myself. my main doubt is whenether i could propperly solder the IC components.

2. Using the ArduinoMega2560 as a base and using a shield to make it compatible with the OP firmware. I know that there is such a shield on the forum, however I do not (fully)know where the arduino sheld and the TCB differ and what capabilities are un-available on the shield option.

what is at the current moment the better option?

[LukeZ]

Hi Alex,

I would recommend against the first option of building the board yourself. Even though I have a lot of experience even I ruined about 40% of all the TCBs I attempted to assemble, and that is a very costly loss rate.

Using the Mega as a base to DIY your own version is not a bad option but unless you add external components many features will not be available. This thread which you have probably already seen has good information. Without any soldering at all, you can get read PPM or iBus receivers (SBus receivers would require additional components), and you can drive any serial motor controller (like the Sabertooth) or RC ESCs without problem. You can also connect the Benedini or Taigen sound card with no work, and if you have a recoil servo, run that too. If you want to turn on/off LEDs you can do that too without additional components (other than current limiting resistors which you need to use anyway), so long as you don't draw more then 20mA per output.

Beyond that you start to need additional components. LEDs with more than 20mA of current draw, the smoker, the high intensity flash, and IR functionality all require MOSFETs or transistors. Airsoft and mechanical recoil is not possible to get to work with the present firmware, because they use pins which the Mega boards do not bring out (even though the Mega uses the same processor as the TCB, it doesn't connect all the pins from the processor). There would of course be no on-board motor driver for the turret rotation and barrel elevation, it would be best to use a cheap RC speed controller for those (since they are such small motors you can easily get away with some cheap ones from China for a few dollars). Of course at this point you start to create quite the wiring mess.

Here is another very fascinating thread by Sergey who took the DIY approach to the extreme. It is in Russian but Google translate works very well.

If you just want to drive your tank around, have sound and a servo recoil, then it is pretty straightforward. If you want IR and lots of external gadgets, or need Airsoft, then it is not really going to be easy or work very well.

I suppose at this point in the project what is maybe needed is a simple shield with through-hole components only that would be easy for lay-people to assemble,  such as Rebus started.

I can't say when or if I would have time to work on such a thing, though I think it would be a worthy endeavor. In the meantime the situation you face is as I've described.

Another option is to post on RCU or other tank forums to see if anyone wants to sell an existing TCB. It's hard to believe, but not everybody liked it! I'm sure they would be happy to make some money.

[Alexk]

Thank you for the reply,

after some further considerations the self assembly option does sound to much hassle with a too high chance of failure.
I have looked at some Chinese companies who could do the whole thing and the per-unit price was predicted to be around 50~ euro except they only sold in quantities of five or more.

I have also taken a closer look at the TCB schematics and compared them with the Arduino mega and Rebus's proto-shield schematics, at first glance it would appear that making a shield would not be too difficult, most of the "modules" in your schematic look like the can be simply plugged onto a mega board without too much difficulty.

At least that looks what Rebus's board is doing, who chose to mostly give the motors and other extra functions outlet ports that could be connected to their own separate function boards.

I think that the main problem will be is determining whether a function (like integrated motor drivers) should be on the board or would better delegated to a separate module.

Would it be possible to reconfigure the output pin for some functions, specifically the machine gun output (and the recoil switch) to a different pin? currently the MG uses E2 when this port is not available on the arduino.

[LukeZ]

Would it be possible to reconfigure the output pin for some functions, specifically the machine gun output (and the recoil switch) to a different pin? currently the MG uses E2 when this port is not available on the arduino.

Yes, this is possible and needed to be done. We used those obscure pins on the TCB because it made board routing easier, but it's of no use for the DIY person trying to make a board with an Arduino Mega.

I have just released a new version of OP Config, on the Firmware tab you will now see an option to download a "TCB - DIY Version" firmware. This firmware will always have the same options and features as the regular TCB firmware, and will be updated on the same schedule, the only difference is that the DIY firmware will relocate those two pins.

The pins that change on the DIY firmware are:

• Machine Gun LED - will now be on Arduino Pin 20 (also labeled SDA on the Mega board)
• Airsoft/Mechanical Recoil Switch - will now be on Arduino Pin 21 (also labeled SCL on the Mega board)

I need to create some updated documentation to permanently record this but in the meantime the new firmware is there and will work for DIY projects.

Please keep us posted if you decide to go the DIY route, but maybe record your progress in the other thread so we have it all in one place.

[johnnyvd]

I have looked at some Chinese companies who could do the whole thing and the per-unit price was predicted to be around 50~ euro except they only sold in quantities of five or more.

Hi Alex, what companies did you look at if i may ask? I would be interested in contacting some of them to start some small batches!

Cheers, John

[Brian Tulk]

Just learnt how to attach pictures, here are a few of the initial TCB setup.