Best posts made by Denke

Hi here is my 2 channel dimmer project that I am working on. The project will fit a 70 mm in wall round box. There are still some things to consider in the design, but i expect that i will be making an order within the next 2 weeks for this prototypes.

If there is interest i can share more about the project

Just for the fun off it i bought a Biltema presence controlled LED lamp for 79 SEK ~9$ having in mind that i should be able to use the nice box and interior to build myself a "cheap" motion detector to add to mySensors project.
http://www.biltema.se/sv/Bygg/Belysning-och-lampor/LED/Narvarostyrd-minilampa-2000033627/

I started by opening the lid and remove the board. This was a little troublesome as i had to compress the battery connector to get it out of its position, but i managed.
After that i tested different ways of how to fit in the Arduion mini and the RF in to the box. Unfortunatly i could not get it in without making the PIR sensor board smaller. I just cut down the board at the near the GND connector.

After this i had cut off the VCC and the motion output so i had to fix that by soldering wires for VCC and motion output shown below. connected pin1 and 8 fixin the VCC. and solderded the Via hole to the testpoint to fix the motion output from pin 2. Also i needed to cut the track just right of C3 to disable the fotoresistor so that the sensor work also in daylight.

I assembled back the board. Also you will need to replace the LED with a 10k ohm resistor (to reduce the current when activating) and then connect the Arduino sensor input to the R3 right side. This should give an active low trigger pulse.

And then i placed the component as i see that they should fit.

Now comes the next step to wire the R Fboard to the Arduino and then connect the motion output to the input of the Arduino.
There might be some changes needed for setting up the right length of the pulses on the motion detector. I have to investigate which of the R's and C's just right to the detector that does this.

This is as how far i came today.

Hopefully this will be one of those projects i finish.

I will make updates on the progress

Hi all
Here is my first mysensors HW that i developed and also my first post. Not all functions are tested at the moment.
I started by analyzing the current thermostat on size and function. Then i took all the info and started working with it in designspark.

My plan is to use this with Openhab

Spec
-Should be able to open/close valve in Uponor system
-Should in the future be able to open the valve from 0-100% (Think i need to change valves for this)
-Should fit in the Wirsbo thermostat mechanics
-The system shall fall back to "old thermostat" function if the home automation stops working by using the knob setting
-The system shall be built as much as possible on cheap components that could be bought on for example ebay

Old System

New system
If only on/off function is requested then the MOC 3023 could be replaced by a a new one with zero crossing detection and then also the zero crossing detector can be omitted (IL250 in the schematic)

Schematic

Result
The HW fits in the old casing
Not all components are mounted at the moment as i have not received them yet, but the board have partial functions

First attempt to see how a box could look like
Diameter 56 mm 50 mmside to side

@hek Its more that i at this moment have not gone through the pros and cons of open hardware. And this is something i will read up on. So Im not saying that i will not share, but i need my time to go through it.

Now the code is tested against openhab2.0 after some work adding HVAC in the binding. Will make a pull request for the binding part soon

Hi all
I will try to answer your questions.

Q: what sort of switch would be on the wall?
For this design i would recommend that you use 230 V rated switch to control the dimmer. The output is still only 0V that you switch on and off. But the design is made in such a way that if you get short circuit on the capacitor in series in to the rectifier there can be 230 V on the input pins ( very unlikely because of other things will burn) but it can happen.

Q: How are you sure that this hardware circuit …….
Doing a little benchmark and understand how dimmers and switches from NEXA or similar are working. Actually I ripped them apart and found out that they were using transformer less designs. From that I Googled this and read up on the topic as well as discussed this with colleges of mine. I then changed some parts as the transformerless design would in simulation not give more than 10mA so I added the MAX 17552 circuit in between and set the input voltage to 24 V with the zener diode and by that I will be able to draw about 30 mA (starting current of the circuit that I tested is around 24 mA).
Q: I suspect this unit is going to be mounted in wall behind……..
Yes of course but just use it as the switch, what I mean is that don’t use at ordinary switch were 230 V is applied. The circuit is designed to just feel a logic zero on one of the inputs. ( just make sure that you read my first reply above for safety reasons)
Q: can we control Celling fan using this dimmer.
Should not be a problem as I have used Triacs that are made for inductive load (not tested though). But the fan should not consume more than 4A. I also have not tested from a heat perspective how much power I can have running in the system. It might be less than the 2 channels times 4A.

Finally new boards have arrived..

Assembly will start soon:)

2 boards completely assembled and working as expected. 3 more to go after ordering the missing components. Now some last fixes to the code so that memory can be wiped by pressing a button and also the check if connected to the home automation system if not a fallback should be initiated

First components added after a visit to the lab at work and some soldering under the microscope

Hi Tomas
I have only replaced the thermostats not anything else in the system.
This thermostat is a replacement of my Cosy thermostat (art no 804661), but i think it should work also for the following article numbers (80466, 80465, 804651 and 80464). This thermostat only works as a on/off for the valve, I did not spend any time on the night temp function. I have connected the thermostat to a transformer unit (art no 80460) which in principle only converts 220 v to 24 V which is then connected to the thermostat. When the thermostat turns on it passes on the ~24 V signal to the valve.

I will upload a schematic to the project

Really great project. Thanks for giving me ideas and inspiration. This was my next step to go for after my thermostat and dimmer project

Thanks Tante-ju and Scalz for helping out with the answer. This is why i stated that you need to treat the equipment as hot, becouse that you don't have control of the reference to ground. But as long as it stays "inwall" and you are using 230 V rated switches on the low voltage switch then the insulations shall be ok and safe. But as soon as you open up and work with it you need to treat is as hot.

@Denke
You look and you look, then you ask someone how to do.

Then you look again and you find it:)
, true after the set message in send did the trick.
gw.send(msgSetpointHeat.set(setTemp,1),true);

No i have not tested any minimum loads at the moment, this is one of the next steps

New boards ordered. Took the oportunity to add an extra connector for SPI. So this in combination with the SDA/SCA will make it possible to add an OLED.

Boards are now ordered. Lets hope they will work fine. I have some doubts about EMI coming from the boards when dimming. So now it will be measure and correct if needed

@ahmedadelhosni
Hi I have used 1M as bleeder in 0603 size. This resistor should be able to handle around 0.1W.

If i have calculated right the power in the bleeder resistor should be around 0.05W

@bjornhallberg The sensors are working fine and have been installed in my home for the last couple of years. Some optimisation needs to be done to the code, that i have not done. This is more connected to understanding when the mysensors network is in "range" as i want to fallback on the manual knob if the mysensor network is inactive for some reason or if i sell the house and the controller goes with me.