I've just built this temperature / humidity node, with a 1.3" OLED display:

The OLED is a 128x64 I2C version, driven by an SSD1306 chip, and will display 8 lines of text - but as I'm short-sighted , I've used double-height text, showing time (from Domoticz), temperature, humidity and battery voltage.

The node uses a Ceech board, and is powered by a Samsung phone battery with a micro-USB connector (top left) to charge it. There is an HTU21D temperature / humidity sensor bottom left. Connectors have been judiciously bent (!), so that the base will fit on the box.

The sketch is based on Ceech's example sketch for the board, with the inclusion of a cut-down, text-only library for the SSD1306 (to save space).

Here are some pics of my multisensor node, using the Ceech board with lithium battery charger. The stripboard houses - from left to right - a BMP180, HTU21D and BH1750FVI. As you can see, I've soldered radio and connections directly to the board, to reduce height in order to fit the box.

The box is the same as the one shown here:
(http://www.ebay.com/itm/85x58x33mm-Waterproof-Cover-Clear-Plastic-Electronic-Project-Box-Enclosure-CASE-/281390875149?hash=item418434020d)

(but purchased from UK eBay website).

I had to shave the board down by about 1-2mm on one edge, to fit the box - sorry, Ceech!

I've been looking around for a hardware solution for an RGBW LED strip controller, and came across this from The CustomGeek. It's a full kit of parts, and is based on an ATMEGA328P with an Arduino bootloader and sketch already loaded. The board uses 4 MOSFETs for the different LED channels, and has some interesting features:

• onboard RGB and white LEDs, which enable you to monitor the colours and levels of the LED strips
• serial interface, with TTL and RS232 level options, giving the ability to send serial commands (such as red50, to set red to 50%)
• an IR interface, using the Adafruit Mini Remote Controller (not included in the kit)
• an FTDI interface, to enable the Arduino to be reprogrammed (new sketches uploaded)
• unused analogue and digital pins brought out to a header, for easy external connection.

As such, I thought it should be possible to 'MySensorise' this, and add an NRF24L01+ radio.

I ordered the kit from the US (took about 2 weeks to arrive). I discovered that the board uses digital outputs 3, 9, 10 & 11, where the radio requires 9, 10 & 11. I got round this by swapping 5 & 11 on the board (cutting tracks, adding links), and changing CE & CS to 6 & 7 in the sketch. I've tried several of the RGB(W) sketches published on this site, and all work well! (I'm using Domoticz as controller.)

I made a few other minor mods to the board:

• I built a small 'daughterboard' consisting of the radio and AMS1117 (to provide 3.3V), and used different headers to enable this to be plugged in horizontally (see pics)
• I mounted the IR receiver on a header, so that I could use this externally from the board
• I changed the values of the resistors driving the onboard LEDs, as the latter were too bright.

I've included some pics below:

I've also developed a sketch, which I'll upload in another post.

I've found that adding this to setup() can cure flickering:

  //Increase Timer frequency to prevent flicker in Pins 5,6 PWM
  TCCR0A = _BV(COM0A1) | _BV(COM0B1) | _BV(WGM00); 

@ceech, could you make a version for the UK - without the flag?

What's the current capacity - and therefore max. no. of LEDs - per channel? (I guess I was expecting to see some chunky TO-220 MOSFETs!)

For an N-channel MOSFET such as IRLML2502, source should go to GND and drain to 12V via the LED strip, as in your diagram (I'm assuming you're using common-cathode LED strips?).

Can you check the pinout of the MOSFET? The datasheet shows different pin numbers: IRLML2502

Got this working OK. I built a MQTT / W5100 gateway as per the instructions in the MySensors Build section, and changed the topic prefixes and controller IP address in the example sketch.

Initially this failed, as I had connected Vcc on the W5100 to 5V instead of 3.3V, and I had the prefixes the wrong way round (i.e., /out instead of /in).

(BTW: I'm using MySensors 2.1.0 and Domoticz 3.6371 - latest / recent beta.)

Hello @GertSanders, for the time being I've got the gateway working with CE connected to pin 15, having carried out some 'surgery' to the board!

I've found this code in PiGatewaySerial.cpp (line 198 onwards):

/* create MySensors Gateway object */
#ifdef __PI_BPLUS
gw = new MyGateway(RPI_BPLUS_GPIO_J8_15, RPI_BPLUS_GPIO_J8_24, BCM2835_SPI_SPEED_8MHZ, 1);
#else
gw = new MyGateway(RPI_V2_GPIO_P1_22, BCM2835_SPI_CS0, BCM2835_SPI_SPEED_8MHZ, 1);
#endif

Is this the 'offending' code?

Is there a 'local' source of PCBs for MySensors (i.e., UK / Europe)?

I've just (14 November) received 3 of @sundberg84's Low Power Node PTH v2 (atmega328p and NRF24L01+) boards from OSH Park in the US, which I ordered on 24 October - panelisation and fabrication was actually quick, and they were finished and posted on 2 November. Elapsed time was 3 weeks, but I understand it can be up to twice this for boards from China (e.g., dirtypcb's).

It would be good if there was a more local source, with shorter elapsed times.

@maghac @moskovskiy82 I came across this some time ago, with an RGB LED project. Whilst I can't recall the details, it's to do with setting the Arduino's PWM timers - apparently, the frequencies of the R(ed) & B(lue) channels can be close enough to causing 'beating', which gives rise to flickering. This statement changes the frequency of one of the channels slightly, thereby eliminating the flickering.

Separately from this, you can find a local 3d-printing service on 3dhubs.com - I found one local to me this way, who did my first print, which got me onto the 3d trail (I subsequently bought a Prusa i3 MkII kit).

...or you can use a 3d-printing service - email them the stl file (follow @dbemowsk's link above, to his Thingiverse page).

Your box looks really good!

Re bevelling: I did a quick Google for 'openscad bevel' - haven't looked at the results, don't know if any of these are what you want.

I've used openSCAD a few times now, to print enclosures, including MySensors and RaspberryPi's (note to self: must publish these here / on Thingiverse), and I like the way you can precisely define shapes through its structured language.

I recently came across an RPi case with rounded corners and edges, which was simply achieved by creating small spheres at each of the corners, and then producing a 'hull' around them:


Here's some simple code which I used to create the above examples:

// Rounded box example
r = 2;
box = [80, 40, 20];
hull_build(box,r);

//Utility module to make a solid box with rounded corners
module hull_build(box,r){
    //spheres at the corners of a box and run hull over it
    x = box  - 2 * [r,r,r];
    difference(){
    hull(){
        for (i=[0:1]){
            for (j=[0:1]) {
                for (k=[0:1]){
                        translate([i*x[0],j*x[1],k*x[2]]+[r,r,r]) //move up r because we moved box up
                            sphere(r);
                            }            
                        }   
                    }  
              }   
         }  
}

I'm using one of these : http://uk.tp-link.com/products/details/cat-5258_HS110.html

I've written a Python script to read this in Domoticz (not MySensors though).

Got this working OK. I built a MQTT / W5100 gateway as per the instructions in the MySensors Build section, and changed the topic prefixes and controller IP address in the example sketch.

Initially this failed, as I had connected Vcc on the W5100 to 5V instead of 3.3V, and I had the prefixes the wrong way round (i.e., /out instead of /in).

(BTW: I'm using MySensors 2.1.0 and Domoticz 3.6371 - latest / recent beta.)

@jpaulin said:

@MikeF
Domoticz can now interpret the MySensors MQTT format from a MySensors MQTT Client Gateway without JSON stuff, it's straight forward. To make it work just change the Topic Prefix in the MySensors Gateway and the rest is solved under the hood. Auto discovery etc works now as any other MySensors Gateway with Domoticz.

Thanks for this, @jpaulin - I'll build an MQTT / ethernet gateway and see how I get on.