Sensornodes: XAmbi Kid's

[Frank Herrmann]

Hello,

first of all. This is my first thread in this Forum

I realy like the concept from mySensors and found this some weeks before. I read all the nice Tutorials and Builds and will show my Concept:

https://xpix.github.io/XAmbi/
https://github.com/xpix/XAmbi/tree/master/Xambi_kids

The Features:

• small footprint (50mm x 28mm)
• use standard RFM12B Modules with small poweruse
• design for this enclousure: (PDF)
• works with standard Coin cell (CR2032) for a ~year
• has a (optional) Booster on board to make 2.5V to 5V for special sensors or relais
• infraed led for TV or IR serial IR communication
• special Sensorboard for stacking

The Software on this kids use the JeeLib:
http://jeelabs.net/projects/jeelib/wiki

The Xambi Gateway:
https://github.com/xpix/XAmbi/blob/master/Xambi-RPI-Gateway/README.md

I use a very robust library with a lot of Features, support the RFM12 and RFM69 Transceivers together.

Here some photos from the last version 0.4:

https://twitter.com/asmartcap/status/587248440112996353
https://twitter.com/asmartcap/status/587679542279540736

Ok, it's enough ... a before i forgot. At this time i work on a MySensors Transportation library:
https://github.com/mysensors/Arduino/pull/100

[dzairo]

XAmbi support tree network like MySensors ?? or only star ??

[Frank Herrmann]

It's only Star, but the jeelib library has an example for a receiver. Problem, the receiver needs to power on for 24/7

Here an example:

http://jeelabs.org/2011/01/12/relaying-rf12-packets/

[dzairo]

this use only 3mA in RX mode : http://www.semtech.com/wireless-rf/rf-transceivers/sx1211/

there is still problem that all project not use synchronization .. if node is register then synchronize ..and all time sleep only predefined time wake up and listening..

I thinking about it .. but ..

[Frank Herrmann]

@dzairo said:

there is still problem that all project not use synchronization .. if node is register then synchronize ..and all time sleep only predefined time wake up and listening..

Sure, but maybe the RFM12B has a solution. He can trigger the mcu if something happends (low duty-cycle). Please read this article, i try to explain what are possible:

• MCU and RFM12 are sleeping
• Only the RX Part from RFM12 are not sleeping and control the enviroment for special "magic Pakets"
• source node send a 'magic paket' signal
• RFM12 receive MP and wake up and send a interupt to mcu to wake up
• RFM12 sends an 'ACK' Signal to source node and wait for answer
• source node get ACK and send data
• The RFM&MCU receive data transmission to relay
• relay and sleep

I hope u know what i mean?

[dzairo]

@Frank-Herrmann ..I know what you mean.. but MP not solve problem.. you can get consumption around 1 ~ 2 mA .. but not less ..
if you really want less than 100 uA power consumption or less then need synchronization..
new modern chip .. Si4432 or similar .. have preamble detection function or similar .. but if not use synchronization then problem is in Tx side ..it's mean mus transmit packet and waiting.. then you can make Rx side where you have power consumption around 20uA and good respond time .. but in Tx side you must still transfer packet ..and there are another problem .. if you try send packet then hold RF link .. no other device can transmit.. etc ..
and there is another problem .. time respond .. you can have sensor node or button node . sensor node can transmit every 1 min and all is OK .. and if you not transmit data now , send later .. but button node .. if you want control any device (light , gate .. etc..) then want respond time less then 1sec .. and if you push button twice or have more button node ??
than in fact .. you can have sensor network with long battery life but respond time is slow , or high respond time and need use AA battery or bigger ..
is possible make compromis but how many node you want use ?? etc ..

best regards ..
PS: thsi module .. Rx only .. low transfer speed but got 70uA only .. http://www.aurelwireless.com/wp-content/uploads/shortform/650200590G_sf.pdf .. still depend what you want ..

[Frank Herrmann]

I guess the process i described need only 100ms in result. The wakup-times and the responses are very fast. But ok ... just my 2 cents. I dont need relays, cuz the range are ~ 30-50 meters in house, thats enough for me

[scalz]

Hi.
@dzairo : you are right. sx1211 is impressive. There is other chip like ZL70250-1 with beautiful spec but it is shorter range and exotic.
So RFM63 sx1211 based seems very interesting. Less TX db than RFM69 and no encryption but very low power like you said (3mA in RX). Plus, it seems to have a great sensibility. I think it should not be so difficult to have a lib for it as it is RFM69 cousin (lot of work anyway to do it). Curious to see vs nrf24. But like you said, for device like buttons, it should need sync like FTSP. Do you have an idea about sync implementation???Do you have a protocol preference?

[dzairo]

@scalz exactly .. synchronization ...