FTDI_simple_alarm

Use a USB-Serial Converter like the FT232RL for activating a buzzer. Simple and cheap (~1,75€)

Features:

• works on GNU/Linux only
• no drivers or other software/libs are requidered
• triggerd via bash or service daemon

Limitations:

• works safe on system with only one /dev/ttyUSB device
• no other task can use the FTDI device for other things

Handware:

1. FT232RL Breakout board ~1,5€
2. NPN Transistor like 2N2222A ~0,0€
3. Active Buzzer 5V ~0,25€

Schematics:

FTDI EEPROM

To invert the TXD pin on the FTDI device, programming the EEPROM is needed. With the Windoofs tool "FTDI_Prog" the Template ft232rl_alert.xml is uplouded. For GNU/Linux is ftx-prog available. The only difference to default is the inverted TXD pin.

Software:

Commmon Distributions

Make shure the device is recocntied as ttyUSB after plug in with dmesg.
Edit the alarm.sh with your device name, like /dev/ttyUSB0.
Run bash ./alarm.sh for starting the alarm.

openWrt

opkg update
opkg install kmod-usb-serial
opkg install kmod-usb-serial-ftdi

Make shure the device is recocntied as ttyUSB after plug in with dmesg.
Edit the alarm.sh with your device name, like /dev/ttyUSB0.
Run bash ./alarm.sh for starting the alarm.

Service

todo