This simple mini-burglar alarm on the ATtiny 13 microcontroller is designed to protect apartments, offices, summer cottages … When the reed switch opens, the alarm beeps or, with a little refinement, you can send an SMS from a mobile phone. The alarm control is carried out by IR remote controls. Main features: dynamic power supply of the photo-receiver, wake-up from the “SLEEP” mode by interruption from the watchdog timer in the “POWER-DOWN” mode, and as a result low power consumption – about 30 μA.
The schematic diagram of the device is quite simple. IR receiver – TSOP1736. The heart of the device is the ATtiny13 microcontroller. When the reed switch contacts open, an alarm is triggered. Schematic diagram of the burglar alarm (click on the diagram to enlarge):
The assembled device looks like this:
The infrared transmitter for controlling the alarm system is assembled on the ATtiny13 microcontroller and a dozen passive components. Instead of the BC847 transistor, you can use any low-power transistor, for example, a CT 315. The power source is two CR-type lithium-ion batteries. Schematic diagram of the infrared remote control to control the alarm system (installation of security / disarming):
Assembled keychain control:
When using a multichannel (99 channel) IR transmitter on the ATtiny24 microcontroller, you can use a large number of nearby alarms at the same time, controlling them by choice. Schematic diagram of the multichannel IR transmitter:
Assembled multichannel IR transmitter:
Erasing all key chains
A beep will sound, the indicator continuously flashes in red 0.5 Hz
Adding new key chains
The indicator flashes continuously in green 0.5 Hz.
In confirmation of the recording keychain beep beeps 1 time.
If the keyfob memory is full, the indicator continuously flashes red with 0.5 Hz.
Work with the device
Arming with the door closed
The indicator flashes red with a frequency of 1 Hz.
Arming with the door open
The indicator alternately flashes red and green with a frequency of 1 Hz.
After closing the door, the indicator flashes in red with a frequency of 1 Hz.
The indicator flashes green with a frequency of 1 Hz.
The indicator flashes green with a frequency of 1 Hz. After removing the alarm, if necessary, arm again.