Wireless Bridge ISM-Band
Introduction
The Wireless Bridge ISM-Band is as the name says, intended to act as a wireless bridge for serial communication,
it is designed to be used for multiple purposes (USB, RS232 and RS485).
The project is build around a RFM12B transceiver, which exists in 315MHz, 433MHz, 868MHz and 915MHz, i have choosen
to use the 868MHz, which i think is to be preferred over 433Mhz, since 868MHz isent that crowded.
The RFM12B is a tremendous little module, where there are many different registers to fiddle with, to gain optimal
speed / range, i have achieved op to 20 meters at 57600 baud (indoor).
The module is specified to have i power output of approx. 5-7 mW, i have meassured the output from the device which
only is 1,5 mW, which is very disappointing, besides that the module is really great, and easy to work with.
Right now i am working on an RF amplifier (RX/TX), that will give a output of max. 40 mW, that should
extend the working range a bit.
Features:
- Power supply DC: 8 - 16 VDC.
- ATMega 128 16MHz (128 Kb Flash, 4Kb SRAM).
- RFM12B-868MHz transceiver. (Linkspeed 9600 - 57600 baud).
- LCD display 2x16 (Green).
- 8 KB Seriel EEPROM.
- Temperature sensor (LM75).
- USB Client.
- RS232 (Console).
- RS485.
- 4 x Buttons (UP, DOWN, OK and CANCEL).
- SMA female connector, with 2,5 dBi attached antenna.
- Extension connector (RS485).
- ISP connector (ATMega 128).
- PCB size: 100x75 mm.
