Author Topic: RFM69 with no Micro-Controller  (Read 1140 times)

Gadjetnut

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RFM69 with no Micro-Controller
« on: November 27, 2016, 10:56:59 PM »
I am new to the RFM69 and am looking for a very low power RF transmitter for door switches. Ideally looking to keep my sensors small and powered by CR2032 coin cell battery. Is it possible to develop software for the RFM69 and eliminate the need for a separate Micro-controller?   Alternatively can the RFM69 be configured to transmit open/close based on the state of an attached reed switch and sleep in between transmits (again without a separate Micro-controller)?

Felix

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Re: RFM69 with no Micro-Controller
« Reply #1 on: November 27, 2016, 11:06:26 PM »
The answer is no. Simply because you have to configure your RFM69 to run at certain parameters (load the registers) and you do that via SPI from a microcontroller, you have to send data, via SPI, so it knows what and when to send etc, can't do that without a micro.

The module is a transceiver, not a micro controller, it is designed to be used by a microcontroller.

I've seen other modules that embed an SX1231h (rf chip used in RFM69) and have a microcontroller - much like XBees. Then they have an AT interface but even those you'd need a serial connection to at the very least, to configure and tell them what GPIOs to set/unset or what data to pass.
« Last Edit: November 28, 2016, 07:53:52 AM by Felix »

perky

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Re: RFM69 with no Micro-Controller
« Reply #2 on: November 28, 2016, 05:22:28 AM »
There is one microcontroller with sx1231 silicon on the same substrate,  the NXP KW0x series, but that has an ARM Cortex-M0+ core. I don't know what the development environment is like but you may have to buy the compiler so IMO it's only for high volume low cost products where you can afford the up front development costs. Also it comes in a dual row QFN package which is a pain.
http://www.nxp.com/products/interface-and-connectivity/wireless-connectivity/sub-1-ghz-wireless-solutions/kinetis-kw0x-48-mhz-sub-1-ghz-wireless-radio-microcontrollers-based-on-arm-cortex-m0-plus:KW0x
Mark.