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DuinoMiteMegaAn
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Joined: 17/11/2011
Location: Australia
Posts: 231

Posted: 04:59pm 18 Dec 2011

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(MM/DM) RF Transceiver Module(s) (ISM) for Home Automation Project

Since the RF transceiver would be used for home automation then it has to meet the following general criteria:

1. Very low cost (The cost per RF node should be very low due to the amount of
nodes needed)
2. Low power operation and must operate on battery (external nodes only) for years.
3. Easy to use and mates well with Maximite/DuinoMite.
4. Does not interfere with Wifi and other Gigahertz consumer devices.
5. 30 meter range (depends on frequency / composite of walls / transmit power -
many variables)
6. Does not tie up the Maximite/DuinoMite resources.
7. RF nodes count should be greater than 10 for home automation flexibility.
8. 3.3 VDC operation, if possible.
9. OTG host RF dongle for master or central RF node, if possible. <-- Edited/added

Note: MM-BASIC implements the SPI the same way as Serial ports with bit-banging and SPI is limited to only 100 KHz.
Note: Most RF transceivers required a packet speed of greater than 100 KHZ?

I came up with the following RF modules "short list" for this project:.
Note: Not all transceivers are ISM (industrial, scientific and medical (ISM) radios for international use)

1. JeeNode (Jeelabs - Arduino 328P with HopeRF/Silabs RFM12B transceiver)
2. Nordic (nRF24L01 -RF Transceiver module)
3. Nordic (nRF8001 - Bluetooth - low power series)
4. Olimex NRF24L
5. Olimex MOD BT (Bluetooth)
6. Olimex MOD MRF24J4
7. Synapse (Python 3 mile LOS radios) <--- Edited/added
8. Xbee <---- Edited/added
9. Texas Instruments ISM Transceiver - CC1000
10. Zigbee (non ISM)

Any board member has his/her favorite to add to this RF Transceiver short list?
Edited by DuinoMiteMegaAn 2011-12-24

DuinoMiteMegaAn
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Joined: 17/11/2011
Location: Australia
Posts: 231

Posted: 06:07pm 23 Dec 2011

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The Arduino base JeeNode is probably the most cost effective ISM RF transceiver
that could be easily attached to the DM/MM for a wireless sensor network.
Stay tuned ...

2011-12-24_041032_MSPNode_JeeNode_Protocol_R2.pdf

BTW ... ISM Frequency per location

Europe 868 & 434 MHZ
US 434 & 915 MHZ
Australia 434 & 915 MHZEdited by DuinoMiteMegaAn 2011-12-25

DuinoMiteMegaAn
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Joined: 17/11/2011
Location: Australia
Posts: 231

Posted: 04:22pm 02 Jan 2012

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I chose the JeeNode (aka Arduino with RFM12B) as the RF ISM transceiver for the DM/MM.

Reasons: Very low cost, low power, packet pre-processor, CRC error checking, packet protocol with acknowlege bit and data Ok flag, and has above all, over 3 years of thoroughly tested, easy to use Arduino software routines for this ISM RF transceiver. There is no use to "re-inventing the wheel" and the costly R&D needed to design, from scratch, RF nodes with a microcontroller serial interface from a un-proven RF transceiver. The Frenchman Jean Claud Whippler did all the work. <---- Thanks.

Note: Since the DM/MM SPI is only 100K then the only solution is to use a RF transceiver with a serial interface to offload all RF data packets.

You need to go to the JeeLabs.com website to see all the JeeNodes, docs and support devices that could be purchase, if necessary. ( I prefer to make my own RF nodes to save a lot of money.)
Link: http://jeelabs.com/

JeeLabs sells a special JeeNode "the JeeLink" which is a JeeNode in a USB dongle or stick. This link provides the serial gateway into the DM/MM. It acts like a RF central server to all the nodes in a wireless sensor network (WSN). What is unique about the JeeLink is all incoming RF data packets are stored into a flash ring buffer. This allows the DM/MM to process other data and just poll or check the serial receive interrupt on the stick for any new receive data. In fact, you could even turn off the DM/MM and still collect the packet data in its 16 Meg flash ring buffer, if you have 3.3 VDC power going to it. What I don't need is many external wireless RF nodes constantly hammering the interrupts to the DuinoMite or MaxiMite or worst yet lose valuable RF node packet data.

Note: The JeeLink cost 33 euro or $43 USD <------<<<<<
I had to design and construct a JeeLink clone (ISM_RF_Link_DM) for the DuinoMite/MaxiMite and to save money.

Note: JeeLabs, the maker of JeeLink, refuses to acknowledge that most microcontrollers today are migrating to 3.3 V from 5 VDC. They have no JeeLink product for 3.3 VDC yet.

I had to reverse engineer the JeeLink because there were many problems (below) going from a
USB JeeLink dongle into a user designed JeeLink clone for the MM/DM using a 3.3 VDC serial only interface.

1, The JeeLink used a FTDI USB chip to power the Arduino / RFM12B radio dongle.
The DM/MM would be powering the Arduino / RFM12B radio with 3.3 VDC.
2. The JeeLink and JeeNode are "overclocked" CPU's running at 16 MHz and at 3.3 VDC. (not 5 VDC) Finding an Arduino clone that could be powered with 3.3 V and with a crystal oscillator was a problem.
3. The JeeLink was programmed via USB. (uses the standard RF12demo program by JeeLabs)(Needed a way to program the Arduino with 3.3 V from a serial interface and to also power the Arduino and RFM12B radio at the same time - needs a 3.3 VDC regulator on the USB programming dongle.
4. The JeeLink has a crystal oscillator instead of the cheaper resonators used on all JeeNodes for power savings. Found an Arduino clone with a 16 Mhz crystal oscillator.
Note: On the Arduino the program fuses between a crystal oscillator and resonator is changed.
5. The JeeLink has 16 Meg of flash to log all incoming packet data in a sequence order. Obtained a proto-shield (from Olimex) which had a 8 pin SOIC prototype area and installed the 16 Meg SPI flash chip on the board to interface to the Arduino / RFM12B radio.
6. The RFM12B radio is only a packaged die - not through holes to mount to a printed circuit board. A person could solder wire wrap wires to this die or find a breakout board for this radio. In any case you would have to connect all the SPI wires from the radio to the Arduino.
7. The data packet timestamp uses millis() for timekeeping. There are better RTC's that could be used to track precise data packet arrival.

To be continued ....

Edited by DuinoMiteMegaAn 2012-01-04

Ray B
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Joined: 16/02/2007
Location: Australia
Posts: 219

Posted: 05:45am 03 Jan 2012

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Andy have you seen the DorJi 433 MHz modules in January 2012 Silicon Chip article which is slanted towards PICAXE but code is similar. Author of article Stan Swan suggests a module price of $25. Lint to product is http://www.dorji.com/
Regards

RayB from Perth WA

DuinoMiteMegaAn
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Joined: 17/11/2011
Location: Australia
Posts: 231

Posted: 05:09pm 03 Jan 2012

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The DorJi cost of $25 is higher than the cost of the JeeNode of $22.

The JeeNode has a Arduino 328P chip front end that would it very easy to serially interface to the MM/DM.

The RF node cost is very critical because using a RF wireless sensor network requires many RF nodes. I came up with a solution which reduces the JeeNode cost by at least half.

Like I said before, the JeeNode has been around for years and all of the software
development has already been done and thoroughly debugged and tested.

I would like to also point out that needlessly tying up a MaxiMite or DuinoMite by having to constantly process the RF node data is a waste of PIC32 resources. Having a "flash ring buffer" to catch RF node packet data is one way to allow the MaxiMite and DuinoMite to process other important GPIO pins. JeeLabs provide this function on their JeeLink

Edited by DuinoMiteMegaAn 2012-01-05

DuinoMiteMegaAn
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Joined: 17/11/2011
Location: Australia
Posts: 231

Posted: 02:30am 05 Apr 2012

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I worked with the JeeNode for several months and its a very overpriced hobby RF
transceiver using the Arduino 328P microcontroller. The ISM SPI Hope RF/Silicon Labs
transceiver is just plain weak in power output and distance. (150 feet max with many limitations)

I split apart this RFM12B transceiver and reduced the cost by 50% by using a Ti MSP430G2553 microcontroller. The trouble is, without the proper RF tools to aid in troubleshooting RF problems, no matter how cheap the node cost is, it is very problematic in getting a reliable wireless sensor network working.

I now decided to switch to RF mesh. RF mesh will get me several miles of reliable
RF communication. Since, the MMBasic hardware is somewhat slow (SPI) then you need
to offload the RF software routines on another controller.
Stay tuned ...

Edited by DuinoMiteMegaAn 2012-04-06

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