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RFM12B Radio


Quantity discounts available
SKU: CP040X Categories: ,


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. Ignore 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.

Note: We are out of the RFM12B 915MHz Radio Modules. The module is being phased out, and replaced by the RFM69C variant. The JeeNode USB works with the 69C just as well as the 12B. You can read more about the RFM69C here.


  • Fully integrated (low BOM, easy design-in)
  • No alignment required in production
  • Fast-settling, programmable, high-resolution PLL synthesizer
  • Fast frequency-hopping capability
  • High bit rate (up to 115.2 kbps in digital mode)
  • Direct differential antenna input/output
  • Integrated power amplifier
  • Programmable TX frequency deviation (15 to 240 kHz)
  • Programmable RX baseband bandwidth (67 to 400 kHz)
  • Analog and digital RSSI outputs
  • Automatic frequency control (AFC)
  • Data quality detection (DQD)
  • Internal data filtering and clock recovery
  • RX synchronous pattern recognition
  • SPI compatible serial control interface
  • Clock and reset signals for microcontroller
  • 16 bit RX Data FIFO
  • Two 8 bit TX data registers
  • Low power duty cycle mode
  • Standard 10 MHz crystal reference
  • Wake-up timer
  • 2.2 to 3.8 V supply voltage
  • Low power consumption
  • Low standby current (0.3µA)
  • Supports very short packets (down to 3 bytes)
  • Excellent temperature stability of the RF parameters


Additional information

Weight 2 g
Dimensions 3.1 × 2.9 × .1 in