Starting motor for 5 seconds after 30 minutes, turning it off and start in reverse direction after 30 minutes

I'm starting to feel like an old engineer suggesting these so frequently recently, but you can use a 555 timer in monostable operation. When triggered (by the alarm), these maintain high signal for a set amount of time and do not accept additional triggers during that time.

You might need to make this as two stages if the original alarm signal continues to set one off when triggered (like if the alarm signal is the driving signal for a buzzer). The way that works is one is high for the length of the buzzer, accepting no other triggers, the output of the first stage triggers the second, which is monostable for the length of the vibration motor. Basically this allows both to be triggered on the same edge, but the shorter duration one can not be re-triggered until the longer duration has run out.

The output of a 555-based astable multivibrator is a square wave, transitioning at two points on the capacitor charge / discharge curve. The output does not track the capacitor charge curve, it has a flat high and flat low. So no, the tone volume should not drop with capacitor charging.

This is true in an ideal circuit, but there may be two caveats for the actual implementation:

• If the tone circuit is entirely powered by the multivibrator's output, it is worth checking if the output of the 555 can cope with the current demand, both average and transient, of your tone generator.
• Depending on the impedance of your power rails and the design of your circuit, both the tone circuit's volume, and the timing for both the oscillators, could either droop or glitch.

Please share a schematic for more specific responses.