aus Metalab, dem offenen Zentrum für meta-disziplinäre Magier und technisch-kreative Enthusiasten.
Version vom 1. April 2011, 20:58 Uhr von Chrysn (Diskussion | Beiträge) (Implementation: clifford measured send time)
Wechseln zu: Navigation, Suche


Nodes are supposed to be equipped with:

  • RF transceiver
  • 4 buttons, labelled with digits, letters, colours (probably red / blue / green / yelow) and symbols (playstation style?)
  • a LED for each button in matching colour
  • an RGB LED
  • a buzzer
  • a 1-wire interface for authentication buttons (iButton)

For ease of development, they also get a serial interface ("FTDI cable" -- power supply + RX/TX + reset, also for flashing using a boot loader).


Both for development and for the final version (as far as we know now), an ATMega328 is used; for development, encased in an Arduino, which also binds the RX/TX pins to a USB serial interface.

As an RF module, RFM12B is used.

The wiring is defined in an eagle file in the project repository.


A little very unprofessional test showed that with the current configuration (through-hole mounted RFM12B with the wire antennae bent to the opposite direction of the pins) with a sender at the whateverlab solder stations a receiver starts losing 6-long packets some steps outside the metalab door front and in the library. Even without further optimization, that should be sufficient for typical class rooms.

Experiments showed that sending a login packet takes about 10ms.