iRTelem is a microprocessor device designed to obtain data from analog sensors and to transmit data via radio. The LoRa standard is used for radio communication. The device supports four sensors. Measurement data obtained from sensors are sent cyclically. Additionally, alarm messages are sent informing about reaching the programmed threshold. Detection thresholds are programmed individually for each sensor. Radio communication takes place in the unlicensed 868 MHz frequency band. The transmitted data is encrypted in the AES-256 standard. Each message contains information obtained from sensors as well as information about the presence of an external power source and the battery voltage level. Each device also receives data from other devices on the network. This information is re-sent via the local RS232 interface. Thanks to this, the device can work both as a transmiting device – a wireless sensor – and as a receiving device – a gateway. A device in the network is identified by a unique ID number and a network mask. Communication takes place between devices with the same netmask value. It is possible to create several independent radio networks operating in the same area.
iSTelem is a signaling device that indicates by light and sound the normal and alarm state of four external inputs. The system is programmable using the I2C interface. The normal state is indicated by a solid green light. An alarm condition is indicated by a flashing red light and a buzzer sound. The device is equipped with a button that can be used to turn off the siren sound, leaving the red light flashing. The system works with the iRTelem device.
