This simple and  funny toy can kill 10 minutes of your time                 
if  you play yourself,  and hours, if you do it with friends.                 

1.2 IR remote control for 'Battle Tank'.

  This IR (radio) control has one interesting feature. It independently controls three electric motors, unlike most others. For example, this is not possible if you use RX2/TX2. Therefore, it is interesting to know how they do it. Of course, everything can be done without opening the hood, but it will free us from additional fun of knowing that inside.
   Let's start with a simple one. Remote control allows you to move the toy forward and backward, and turn the turret left/right. In addition, the 'Fire' button, lights the LED on the barrel once per click.

   Inside you can see on the right. There is only a chip, covered with black compound, under the board. Timing runs from 6MHz crystal. I installed only a jumper (K1/K2) that allows me to switch between toys number 1 (gray color) and 2 (beige).

     Operates on a standard 38 kHz sub-carrier, transmits only when a button(s) is(are) pressed. After releasing the button, it transmits three more codes. Interval - 80mS.


  If we stretch the code in time, for example L-Fwd (Left-forward), we will see the following ('high level' - no carrier, 'low' -  38 kHz is ON).

  The figure shows the time intervals. The coding of "zeros" and "ones" is similar to "the idea' contained in the TX5 set. The transmission of each bit begins with a sync pulse. If it is followed by a long pulse, then it is “1”, if pulse is  short, then “0”.

  To keep it short,  the following picture (from logic analyzer) shows how this happens in real life.

        After the start pulse, 13 bits are always transmitted, of which:

- first 3 - toy number;
- the next 7 - "on-off" information;
- last 3 - checksum (simple sum of "1's" in the transmitted sequence).

  And as an example - a sequence when several buttons are pressed together.

  Forbidden combinations ('left forward' and 'left back', simultaneously) turn into code combination "13 all Hi", or are ignored for transmission.


*** Any inaccuracies on this page will be corrected if you let me know (e-mail is highlighted next :)  ***

_ Updated 08.12.2019 SKootS

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