@nca78 said in Security: 433 RFX vs Mysensors security:

@chbla said in Security: 433 RFX vs Mysensors security:

@nca78 I'm still deciding what to use. Pro Mini if I don't find anything better.

I'm interested in where you buy your BME680 breakout boards, there are not so many around :)

I think I bought them here: http://www.watterott.com/de/BME680-Breakout
I'm located in Austria

@nca78 I'm still deciding what to use. Pro Mini if I don't find anything better.

@nca78, unfortunately, I can't make my own boards so I have to use breakout boards.
However, it's not really a problem as I want to stay flexible anyway.

Thanks for the explanation! I will now rather invest into more Mysensor nodes + RFM69 as it's simply more flexible.

@Nca78 the reason I'm also using mysensors on the temp nodes is that it allows me to use custom sensors (for these types mostly BME280/680).

@mfalkvidd said in Security: 433 RFX vs Mysensors security:

@chbla when combined with encryption, the MySensors signing does a pretty good job of obfuscating what is going on. But since the mere existance of a radio message leaks information, encryption does not solve the problem. Sending fake radio messages at random intervals might be a good way to further obfuscate what is going on, but if an attacker sets up a camera or tracks your phone there will be information leakage again.

Do you have any links to what people use already in terms of encryption?
In any way it's a valid point to say that the likelihood of someone actually monitoring this is quite low.
However, since those chinese 433mhz devices are used so often, it's a bad feeling.
If only they weren't that cheap :)

I wonder how others are doing it, or if most people just ignore that problem?

Yes I have read it, however, it does not address the problem of actually hiding what's going on.

Hi there,

I want to equip parts of house with door/window and PIR sensors.
I initially tought that I will use cheap 433mhz sensors that are integrated with RFXCOM into openhab (which is also the sink for my mysensors network).
They are around 3-4$ per sensor. I would then only use mysensors for things like temperature monitoring, some actors, etc.

However, the obvious problem is security. With those cheap 433mhz sensors it is pretty easy to just listen and tell when my basement door or a certain
window is open or not, if someone really wants to (ignoring the chances right now).

Mysensors seems to be more secure here, but I assume that there are limitations regarding encryptions.

How do you see this and how do you do it? Any suggestions appreciated..

I need help :( - I have soldered the whole thing to a prototyping board, and now the Pro Mini keeps resetting.

Does anyone see a problem in the following schematic? (sorry for the drawing, I'm a bit limited here).

As mentioned I'm using a MOSFET, switched on/off via Pin 7.

Mosfet: https://de.aliexpress.com/item/10PCS-IRLB8721-TO220-IRLB8721PBF-TO-220-free-shipping/32714364118.html?spm=a2g0s.9042311.0.0.FjZdIJ
Vreg: https://de.aliexpress.com/item/2pcs-DC-DC-Power-Supply-Converter-Step-Up-Boost-Module-1A-3V-to-5V/32598574742.html?spm=a2g0s.9042311.0.0.IFPbYZ
Lvl Converter: https://de.aliexpress.com/item/Free-shipping-1pcs-4-channel-IIC-I2C-Logic-Level-Converter-Bi-Directional-Module-5V-to-3/32670479389.html?spm=a2g0s.9042311.0.0.OAwsE9

It was working fine on the breadboard, but I have verified all the connections.

Right now it seems to reset all the time (2nd LED blinking on the arduino).
The regulator switches on and off with 1hz, the voltage between I+ and I- changes between 1.0V and 2.4V
If I connect GND to the regulator directly, bridging the Mosfet, it works.

Any idea?

@qqlapraline good to hear! :) Thanks for the confirmation

What I mean is, those should be connected to GNDT not GND as in your diagram - right?
GND is permanent ground.

I noticed I'm losing current through the trigger pin, the cause is apparently that if disconnected, the system is only on VCC.
Since the trigger bin is set to LOW in my previous sketch, it loses current there.

But I found out that if I set the trigger pin to HIGH before sleeping, it's fine. My sketch uses 78ua while sleeping. Using a MOSFET at the moment
to switch.

I have a working setup now, however, it seems that I lose current through the trigger pin.
If I disconnect it, it drops.

@qqlapraline what I don't get is: Do you really have GND on the high side of the LVL converter connected to GND as in your schematic?
Since the GND sides on the converter are connected, this closes the loop for the regulator, thus it would be turned on all the time?
Same for the HC-SR04

Thanks!

@gohan is that possible with mysensors and the RFM69s? (I have it open, but did not yet read the security docs)

That's a good and valid point speaking for mysensors - right now I only use them for my weather sensors so I did not look into security with the RFM69s yet.

@gohan Can you elaborate? You mean as a reason against the chinese ones? And due to what?

Hi there, I need your opinion:

Say you want to equip a room with 2 reed switches (2 windows), 1 Temp/Humidity sensors and a PIR.

For temperature I'm using DIY mysensors nodes (433mhz), and I could do the same for the windows and PIR.
However, I also have a RFXTRX433e for my blinds, and the price for 433mhz sensors is so extremely cheap these days
I wondered if I shouldn't just combine/mix those in addition to my mysensors nodes.

Reasons for chinese sensors:

• cheap (Door/Window sensor: 4.5$, PIR: 4.9$)
• no hassle, less effort to build
• nice case
• easy integration
• good enough for the task

Reasons against:

• I could combine 2 chinese window contacts into one mysensors node with longer wires if the windows are
  close to each other
• I could eventually re-use the temperature node (although the position at the window is not optimal)
• PIRs not very configurable (delay between triggers, etc).
• usually no batter state transmission (I would simply work around this with a trigger that if I do not receive
  an update within timeframe X, I get notified)
• security

I'm interested in opionions, I assume some people had this decision as well - what are the pros and cons you
determined?

Thanks,
Christoph

I was referring to the TX power, right.

Thanks a lot for the answers! I guess in this case it's much more more flexible to go with the HCW layout.

Hi there,

A quick question: Does anyone know if the libraries for the RFM69 allow to use the HCW in low power mode?

I would prefer to use boards with HCW layouts instead of 2 separate ones for HCW and CW to be more flexible.
But I'm not sure if
a) the HCW can be used in low power mode and b) if it equals the power consumption of the CW (or if there are any benefits
using the CW).

I heard that some libraries allow auto adjusting the transmission power based on the RSSI - does anyone know something about this?

Thanks a lot,
Christoph

I tried this with a similar setup but RFM95 for LoRaWan and without the transistor as I'm testing it directly on USB.

A pololu 5V stepup regulator does not even work directly on VCC - if I connect the HC-SR04, voltage drops from 5V
to 1.2V after the regulator.

I then tried a different regulator from aliexpress, this setup works with the regulator on VCC, but if I try to control it through a
Pin, Voltage also drops and does not even power the regulator (it has a LED) :(

Thanks for the suggestions! I think I will first try the LED stripe way, it's probably the easiest for now.

@Koresh would it be possible to sell this without the sensor part and RFM69? How many orders would it need?
I don't have the possibility to produce it myself, don't need the sensors part and have a lot of RFM69s lying around..

Thank you,
Christoph