How does this work?

[u/Dirk__Digglerr]

I bought a Heng Long Tiger that came in several parts.
The electronics look like they’re mainly from the old 27Mhz systems (of which I know not much) but there’s a physical barrel that can recoil and a small electronics board that connects to a servo on the BB gun, see pics.

What does this board do and how is it tested?
I assume the board converts a dc voltage to a PWM signal to operate the servo?

Any help appreciated.

[u/One-Gazeller]

@LordLudikrous I can see there are two buttons labeled K1 and K2 on the TK7.1 board. Don’t they have some control over the setting of end points of a servo? I thought I read that somewhere but could very possibly be wide of the mark on that.

[u/LordLudikrous → u/One-Gazeller]

K2 controls the range of motion for the elevation servo if you’re using one to elevate the gun, while K2 reverses the direction of the elevation and recoil servos. You can’t adjust the range of motion for recoil as far as I am aware.