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Topic: Wireless control of multiple receivers (Read 2274 times) previous topic - next topic

nervusvagus

Oct 29, 2015, 11:47 am Last Edit: Oct 29, 2015, 11:54 am by nervusvagus
Greetings. I need a simple setup at home to shut down all the electric blinds as I'm leaving the house.
I plan to put a switch by the exit door.

 Basically when I turn the switch down all of the 5 blinds at home will shut down. When I turn it up, all the blinds will open.

I have been researching so many options:

Bluetooth HC-06: Does not support multiple nodes / multiple receivers.

XBEE: Expensive and does not seem so intuitive, there are so many devices to choose from its impossible to find the ideal solution.

CC3000 WiFi chip: This from Adafruit I believe is also not supporting multiple receivers.


nRF24L01: Following this path at the moment with great pain.  This is geared towards having multiple sensors reporting to one receiver. So its almost like bluetooth in the sense that I have to open up a pipe one-by-one between the switch which is the transmitter and all 5 receivers, in sequence. Even if this is a solution it will be a hard work to organize. I couldnt get it to work on Leonardo but Arduino Nano seems to be functioning fine.


nrf905se: Not sure about here.


esp8266: This is one of the wifi modules again.


various 433mhz solutions: Didnt have a time to check on this yet.


Could someone guide me in some path for this? Should I research further into nRF24L01 until I learn the insides completely? Or is there a simple solution where I can get all the receivers to listen to the master transmitter all the time? I do not need a two way communication I just need 1 transmitter with a switch at the door and all the arduino nanos connected to the blinds listening on this one...

Domino60



So you just want to open and close your blinds remotely?
Best option is nRF24L01 You program one Basic transmiter to transmit data for example CH1
and you program the rest as receivers at CH1 as well, all receiver modules will receive data in the same time.


For example:
We got 6 people in a room 5 of them speak in english only and 1 speak Korean language.
One of the english person give a presentation in english language and 4 of the people can understnad
but the only one who can't is the Korean guy because he can't speek english.


It's the same think for your modules as well, if the Main module transmit the data as ON or OFF, the other modules will understand if they receive data in the same Channel and same "language".


So you got a button on your main module and press it once the blinds all blind modules receive the data
and they close the blinds.


ps (Do you use any type of motors for you blinds or you already got that steps?)



D.60
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nervusvagus

Thank you I will keep studying nRF24L01 . Yes the blinds already have electric motors

jrdoner

I have used very simple, and very inexpensive, OOK transmitter/receiver pairs for links in my house.  OOK means on/off keying.  It is very simple: you apply 5 v. to a pin on the transmitter, you get a sine wave output lasting 'til the 5 v. goes to ground.  The receiver likewise has an output pin that is low until it detects the right sine wave frequency, then it goes high.  433 Mhz. is a good choice -- signal goes farther than higher frequencies.

You could probably do this with no microprocessor at all.  Operate a set/reset flipflop (CMOS or TTL parts abound), at the blinds end with the receiver pulse from an OOK receiver, and just trigger an OOK transmitter at the door switch.  If you are not familiar flip flops, just google 'em up.   I think you could build this whole system for under $20.00.

DuaneDegn

#4
Oct 30, 2015, 04:47 am Last Edit: Oct 30, 2015, 04:51 am by DuaneDegn
I've used many of the items you've mentioned.

I'll add my thoughts on the options I'm familiar with.

Bluetooth HC-06: Does not support multiple nodes / multiple receivers.
HC-O6 Bluetooth modules are slave devices only. They need to communicate with a master device. The master device is often a PC or smartphone.

The HC-05 modules can be configured as either a master or a slave. If you had six HC-05 modules you could make one a master and set the other five as slaves. The master would need to be told which slave to transmit to but it should be able to transmit to all five slaves one at time.

XBEE: Expensive and does not seem so intuitive, there are so many devices to choose from its impossible to find the ideal solution.
Yes, XBees are expensive but they're pretty cool devices. XBees come in several different flavors. One type of XBee is the Zigbee version. With the Zigbee setup you have one coordinator and multiple router/end points (I'm not sure I'm remembering the terminology correctly.) There needs to be one and only one coordinator but any single XBee in the network could communicate with any of the other XBees. There's also an option to "broadcast" a message to all XBees in a network. I think XBees might be the easiest of the options mentioned but they would also be the most expensive option.

nRF24L01: Following this path at the moment with great pain.  This is geared towards having multiple sensors reporting to one receiver. So its almost like bluetooth in the sense that I have to open up a pipe one-by-one between the switch which is the transmitter and all 5 receivers, in sequence. Even if this is a solution it will be a hard work to organize. I couldnt get it to work on Leonardo but Arduino Nano seems to be functioning fine.
I'm a big fan of nRF24L01+ modules. These things are fast and very inexpensive. Any nRF24L01+ module should be able to communicate with any of the other modules in the area. I'm pretty sure these modules can just communicate with one module at a time but this isn't really a big deal.

SparkFun used to sell a "Nordic fob" with five buttons and one of these transceivers inside. I loved these things.

Back when I used these nRF24L01+ modules a lot, I'd have the messages hop from from station to the next so if one module from out of range with the base station module, the message would still get to the destination by passing through a module between the base station and the target module.

All my experience with these modules was using the Propeller microcontroller with a driver I wrote myself. I don't have experience using these modules with an Arduino but I believe there's a very nice library for using these modules with the Arduino. I'm sure you know more about this than I do.

I agree with  Domino60 that these modules are likely a good option. I didn't follow what he was talking about channels or for that matter I didn't understand why there's a need to open a pipe to a module.

When I used these modules, each module had its own address and one module would communicate with another using the address of the target module. I suppose these addresses could be considered channels but the modules also had multiple channels to select from. I never used these channels as a way of indicating a target module but I suppose that an option.

There are also "pipelines" which could be used but I rarely used these.

I personally think the nRF24L01+ modules are worth learning to use. They're a really inexpensive yet powerful tool for wireless communication.

esp8266: This is one of the wifi modules again.
I have a couple ESP8266 modules but I have yet to use them. I think these are another possible solution for this application. I'm not sure since I haven't used them, but these might be the easiest alternative.

The ESP8266 includes a microcontroller of sorts and I believe these can be used without an Arduino or other microcontroller. I plan to learn to use these modules and I think these are another powerful and relatively inexpensive wireless option.

I don't have experience with the other modules mentioned.

It seems like you're on the right track. Good luck with the project.

jremington

#5
Oct 30, 2015, 04:56 am Last Edit: Oct 30, 2015, 04:58 am by jremington
An inexpensive and reliable option is an RF keyfob, with multiple receivers, like this.

Choose the "toggle" receiver option to alternately open and close blinds on a button push. Also, one receiver could operate up to four sets of blinds independently.

For maximum range you need antennas on both transmitter and receiver. 17 cm of straight wire is a good choice for 434 MHz.

Domino60



Reading the above other arduino mates I came to mention something,
If you got or you want to control your electric blinds at 2nd floor I would suggest you to buy as
transmiter a nRF24L01 PA 2db SMA and a simple ones as receivers, why?
Because simple nRF24L01 with on board PCB antennas are not good as transmiters because if you
turn them around in a wrong angle they are not able to transmit.

At this point if you got a huge house like 3+ floors, +200 square meters and if you want to upgrade extra stuffs in the system in future I would suggest a 300~500 Mhz Transciver because the waves are bigger and transmited
thru walls better than 2.4Ghz of the nRF240L01 but as I said above if you get the PA 2db one you will
not had big problems.


At this point it's your choise.


D.60
To be or not to be? Read a book and you will see.
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nervusvagus

Thank you I already have the nRF24L01 PA 2db SMA one. I havent tested it yet but it looks like a good solution for these as well. nRF24L01's were a really good solution to these once I figured out the code.


I'm still struggling with the logical operation of the relays, and the relays themselves. I tried to get into learning Finite State Machines as a constructive solution but that seemed like it would take a long time so I'm just juggling different code for the different inputs I have: local switch, remote switch & auto timer

OldSteve

#8
Nov 06, 2015, 01:27 pm Last Edit: Nov 06, 2015, 01:28 pm by OldSteve
Those cheap little 433MHz key fob units as mentioned by jremington are surprisingly good. Having the lower frequency gives them a bit more 'punch-through', so solid objects are less of a problem than with the higher frequency modules. I use them for my workshop alarm system, for simple on/off control. They have user-configurable addresses, and it's easy to set multiple receivers to the same address. 8-bit tri-state addressing, so 38 potential addresses. Probably the easiest and cheapest option.

For longer range and more complex data transmissions, I use APC220 and Dorji DRF7020D13 433MHz modules. (The same thing - both use the RF7020 chip.) They supposedly have in-built addressing, but I could never get it to work, so just use identifiers in my serial stream. The workshop alarm uses these to send alarm status to both the PC and a stand-alone unit. They punch straight through a steel garage door from 30 metres away without problems.
They also have the advantage of adjustable frequency within a fairly wide range, so up to 100 individual channels are easy to set up. 256 byte data buffer, data baud rates from 1200 baud to 115200 baud and RF baud rates from 1200 baud to 19200 baud. 20mW output power. About $20 each.
Please do not PM me for help. I am not a personal consultant.
And others will benefit as well if you post your question publicly on the forums.

DuaneDegn

I once tested some cheap nRF24L01+ modules in our home. I live in a two story house (split to four levels) and I found the little modules could communicate with another module from any two places in the house with a few exceptions. These exceptions were occurred when there was a large metal appliance between the two modules.

I was very surprised how well the little $2 modules perform.

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