The RFM12B radio is the FSK (frequency shift keying) radio that we use on JeeNodes, JeeLinks, JeeUSB boards. The radios are manufactured for use in the 434 MHz & 915 MHz bands for use in US and Australia; and 434 & 868 MHz for use in Europe.
Modern Device stocks the 434 & 915 MHz band radios. For 868 MHz radios see the JeeLabs shop.
The picture of the model we stock is on the bottom left in the picture. I had originally priced them in pairs thinking people would want to buy two, to communicate with each other, but it’s also true that someone could use a JeeNode board to communicate with a custom project, so I’m selling them singly now.
For the technically oriented, here’s a pleasure-filled read from the HopeRF website. I’ve taken the liberty of adding a few paragraph breaks for breathing room. Despite the mention of “adding a crystal” the module contains the crystal and everything it needs for wireless communication.
Hope’s RF12B is a single chip, low power, multi-channel FSK transceiver designed for use in applications requiring FCC or ETSI conformance for unlicensed use in the 433, 868 and 915 MHz bands. The RF12B transceiver produces a flexible, low cost, and highly integrated solution that does not require production alignments. The chip is a complete analog RF and baseband transceiver including a multi-band PLL synthesizer with PA, LNA, I/Q down converter mixers, baseband filters and amplifiers, and an I/Q demodulator. All required RF functions are integrated. Only an external crystal and bypass filtering are needed for operation.
The RF12B features a completely integrated PLL for easy RF design, and its rapid settling time allows for fast frequency-hopping, bypassing multi-path fading and interference to achieve robust wireless links. The PLL is high resolution allows the usage of multiple channels in any of the bands. The receiver baseband bandwidth (BW) is programmable to accommodate various deviation, data rate and crystal tolerance requirements. The transceiver employs the Zero-IF approach with I/Q demodulation. Consequently, no external components (except crystal and decoupling) are needed in most applications.
The RF12B dramatically reduces the load on the microcontroller with the integrated digital data processing features: data filtering, clock recovery, data pattern recognition, integrated FIFO and TX data register. The automatic frequency control (AFC) feature allows the use of a low accuracy (low cost) crystal. To minimize the system cost, the RF12B can provide a clock signal for the microcontroller, avoiding the need for two crystals. For low power applications, the RF12B supports low duty cycle operation based on the internal wake-up timer.