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Specification

nurazur edited this page Jan 21, 2020 · 4 revisions

General

  • Operating Voltage from ca. 1.8V to 3.6V
  • Operating Temperature -40 to +85 degC
  • Operates with a CR2032 cell up to 5 years
  • various PCBs fitting into selected PVC boxes (PVC material limits operation range!)

Radio

  • RFM69CW, RFM69HCW, RFM95, CC1101 Module
  • bidirectional communication
  • ISM Band (Europe: 433MHz / 868MHz, US:315MHz / 915Mhz)
  • 2GFSK Modulation, 19200 Bd, FM deviation 30kHz
  • Center frequency adjustable
  • Frequency correction can be calibrated
  • Transmit power from -18 dBm to 20dBm, 10 dBm typ.
  • Link budget up to 120dB
  • sensitivity -105 dBm typ.
  • range t.b.d., but its looong!
  • ground plane antenna (default) or external antenna
  • RF communication encrypted
  • FEC (Forward Error Correction)
  • Interleaver

Baseband

  • Atmel (Microchip) ATMega328p-au
  • 32kByte Flash
  • sleep current ca. 0.5 µA without timer (remote control)
  • sleep current < 2µA with external crystal 32.768kHz
  • sleep current ca. 4.5µA with internal RC oscillator
  • 1 MHz clock allows operating voltage down to 1.8V
  • 8 MHz clock for gateway receiver
  • I2C bus
  • min 4 additional GPIO
  • Battery monitoring during transmit burst
  • CPU can be locked to avoid reading the flash code

Sensors

  • HTU21D
  • SHT21, SHT20, SHT25
  • SHT30, SHT31, SHT35
  • I2C Bus based sensors can easily be integrated
  • 4 digitale GPIOs

System / Software

  • Open Source Software C++
  • Software can easily be adopted individually
  • Programming tool is Arduino IDE
  • rugged Bootloaders
  • Configuration of Nodes via serial interface (FTDI Adapter)
  • python tools for configuration / calibration (semi-interactive terminal program)
  • configuration data and calibration data reside in EEPROM
  • EEPROM encrypted
  • Flashing
    • using ISP Adapter or
    • serial with FTDI Adapter and Bootloader
  • up to 4 external interrupts (i.e. push buttons) can be configured

Security

  • RF traffic encrypted with individual Passphrase
  • CPU can be locked to avoid reading the flash code
  • EEPROM encrypted to avoid tempering of configuration
  • "Rolling Codes". Together with Encryption it will be VERY difficult to "copy and paste" a RF Pattern.
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