Category: Field Notes and Experiments

After giving-up with my Dash-Buttons (see Dead of Amazon-Dash)

Setup DeConz and Conbee on RPI3

Install ConBee and  DeConz headless on Raspberry based on https://phoscon.de/en/conbee2/install

Start DeConz from remote ubuntu server via SSH:

ssh -XY openhabian@pi

DeConz and Openhabian are using the same port for WebServer, change port (also for the Rest – Interface

deCONZ -platform minimal --http-port=8082 --ws-port=8081 --auto-connect=1 --dbg-error=1

Autostart DeCons with service config, info: https://github.com/dresden-elektronik/phoscon-app-beta/issues/26

sudo systemctl edit deconz
# /etc/systemd/system/deconz.service.d/override.conf
[Service]
ExecStart=
ExecStart=/usr/bin/deCONZ -platform minimal --http-port=8082 --ws-port=8081 --auto-connect=1 --dbg-error=1

Other commands to schedule:

sudo systemctl enable deconz
sudo systemctl restart deconz

Configure OpenHABian

Binding for sensors:

https://www.openhab.org/addons/bindings/deconz/#dresden-elektronik-deconz-binding

Binding for lights (deconz can use Hue binding) with adjusted config:

Bridge hue:bridge:2 [ ipAddress="192.168.1.106", port="8082", userName="xxx" ]

It all started with an article in my favourite computer magazine Heise – WLAN Plug with Tasmota. So I could control some 220V devices, like a floor lamp with my OpenHAB Super-Cheap – Smart Home Solution Smart Home.

Some 220V devices don’t need a plug, I want to control them with a tiny switch and not a big plug on the wall, here I found this- 4€ each from China…will this work?

After one month of waiting, 3 arrived. Looked actually quite good!

Its actually amazing, what you get for 4€, and ESP8266 micro computer with WiFi and all the hardware to control 220V / 10 A = 2200W)

But: Its firmware is from China, you need to register an account somewhere and the little switch will connect to it and send your data somewhere – I cannot control.

Wo we need to exchange the firmware on the switch, the brand “Sonoff” is well known for an “easy to way” to do this

The firmware solution of my choice is Tasmota, an OpenSource SW that connects the device only into the internal WiFi network and provide a user-interface to configure the device. So we need to do 2 things to get it running:

1. Flash new Firmware flashed on the switch
2. Integrate the switch into OpenHAB (smart home open source SW)

Preparation

Pretty easy thing (all here: Details), you need:

1. Image “tasmota.bin” from Tasmota: https://github.com/arendst/Tasmota/releases
2. Flashsoftware to reprogram the device with the image from 1): tasmotizer
3. A wire to to connect your PC via an FTDI (serial2USB converter) with the switch, the FTDI and the switch have signs on it, so has the switch:
   

   FTDI	Sonoff Smart Swtich
   3V	3V
   GND	GND
   TXT	REC/RXI
   REC/RXI	TXT

   
   It takes 5min of soldering, when ready it should look similar to below:
   

Flashing

The switch needs to be connected with the PC via our nice cable, it just works by putting it in and a bit of adjusting.

To get the switch in the “programming mode” the reset-button on the switch must be pressed *before* connecting the switch via USB cable to the PC. Once connected, you can release the reset-button (its the long black stick).

Then start flashing with tasmotizer by selecting the firmware and the USB interface:

After re-power the switch, it opens an access-point and you can be configured via connecting to its WiFi (some AP with “tasmota” in the name) , so it will later connect to your own WiFi. But much more elegant, you can use tasmotizer via the button “send config” to update the WiFi directly, you will need to enter the credentials (SSID and PWD from your home network).

All your credentials and data remain will remain in your network now. On the router I also disabled the internect-connection for the IP address of the switch in my home network – just to be save 🙂

Configure the Switch – Tasmota is great

When all works, the switch will connect to your home WiFi, you can find its IP address in your Router and you can open its main config page via a web-browser. You will see the new firmware from “Tasmota” active, that gives you full control over the device.

Its an amazing software, full Opensource, not cloud connection or internet needed. It stays in you home 🙂

The basic tasmota configuration is already correct, nothing to do, maybe in the settings section, you may enter a backup WiFi address – if you want.

Connecting to OpenHAB

The Switch Side

The concept is, that the switch will use the MQTT protocol to communicate with OpenHab, once configured the switch will listen for a message via this protocol and do its job – ON/OFF.

To configure MQTT you need configure your OpenHab server IP and the credentials of the MQTT network, that you have configured in OpenHab. The trick is the “topic”, that is the “address” that the switch will listen towards – any message with this topic will be processed by the switch. For my network I gave each switch its own topic, like “sonoff1”, “sonoff2” – so I can control them separately. OpenHab has a binding that keeps the link to this protocol and its easy to configure.

The OpenHab Side

After installing the MQTT Binding in OpenHab, I did the following configuration, important to have the topic “sonoff1” correctly everywhere:

Bridge mqtt:broker:OH2mqtt "MQTT Broker" @ "MQTT" [
    host="192.168.1.106",
    port=1883,
    username="OpenHAB",
    password="xyz"

] {
    Thing topic sonoff1 "Sonoff1" @ "MQTT" {
     Channels:
     Type switch : ch1  "Light1" [ stateTopic="sonoff:stat/sonoff1/POWER", commandTopic="cmnd/sonoff1/POWER" ]
    }
}

To enable and disable the switch, its straight forward:

Switch Sonoff1 "Light1"  	 	 	 	 	 	 	 	<light> ["Switchable"] { channel="mqtt:topic:OH2mqtt:sonoff1:ch1" }

 sendCommand(Sonoff1,ON)</light>

Enjoy 🙂

After a long time the MCW was standing outside in the cruel world – now I found its time for a real home  – lets build it a home with 3D Printing.

I have used Tinkercad before, for my calendar (check out this picture)

Now, the MCW Watch-Case is more complicated, because – when I build the watch and the PCB – I did not think about the case. Hence -the case had to be build around the watch.

To get this done, I first measured all components of the MCW, starting from the e-Ink Display, the PCP, battery..everything. And build the case around it:

Actually, for me that was the only way to visualize the full result. I want to glue the different parts together, and fill in all components from the top.  Not sure, if I considered everything 🙂

For ordering I used http://www.treatstock.com

Its important that you should export each part separately from Tinkercad and upload as STL file to the order – after export into STL its not possible to get the files separated.

My order now is in Treatstock, 17€ including shipping – cant wait for the result:

How will the final result look like:

 

 

Introduction

I am using a 1.8 Inch LCD Screen SPI Serial Port Module TFT Color Display Touch Screen ST7735 (128*160)  for Arduino”, bought for 9€ from aliexpress.com.

Details: Display Processor: ST7735, Touch Processor: XPT2046, Display Type: ZJY180-TV2.0,128*160, as ESP8266 I am using the WEMOS D1 Mini Pro (v 2.0) https://wiki.wemos.cc/products:d1:d1_mini_pro.

Its part of my Project “BigPi” to use the PI4 as my central home server. I decided it needs a display.

Things should look nice..so what did I do?

Actually I got the Touchdisplay running at the RPI after a lot of tries  – but what do I have on my desk:  A big black RPI4 box with a touch-display. Not looking good.

My alternative: I build a tiny Touchdisplay with ESP8266 in a little box with battery, that I can place anywhere. I will communicate via WIFI to my RPI. No black box on the desk, just a cool multifunctional switch and status-display for RPI Remote control. Kind of a long running project – lets see how it goes.

Wiring – how to get it together

Of course, from china – there is not much documentation. Below some information I found at AliExpress about the display and all contacts at the display have labels. To note: PEN (11) is high, and gets low, when the display is touched – so can be directly linked to the Wemos (see below).

Some Details about the WEMOS D1 Mini Pro

Understanding the Solder-Pads

This is a very nice ESP8266 processor, small size and including LiPo charger unit, so any 3.7V battery can be directly attached on it and can be charged via the mini USB. Its Pin-Compatible to the well known WEMOS Mini, that has some interesting soldering-pads on the back:

• SLEEP: This connect the Reset and the XPD_DCD – Deep Sleep Wakeup, so the WEMOS can waket-up itself from Deep-Sleep. For easy programming and the serial interface to work, this should not be connected. So do it, before you put it into production
• BAT-A0: Links the battery power to the analogue A0 input, so its possible to measure battery voltage (to detect low battery).
• LDO_EN: To disable the 5V regulator, so you can provide your own power source directly to the 3v3 and GND pins. Useful for battery operations. If you use standard lithium ion batteries that have 3.7-4.2V, it’s better to connect them to the 5V pin, since that is connected to an LDO converter.

Deep Sleep…tzzzzz…

I need “Deep Sleep” with ultra low power consumption, as it should run for a long time.

I measure current 0,15mA (150uA) out of the box for the WEMOS Pro Mini via the ESP.deepSleep(), with a 1200mAh LiPo it comes to 300 days.

If its running with display connected, but without backlight (BLK to GND), its consuming 0.48 mA (500uA) – what is approx 100 days runtime, 3 month is ok 🙂

When the display is active and backlight is on, it consumes around 20mA, when the display is off -it goes down to 1mA.

To Remember

During the Deep Sleep period GPIO_16 are held high. At the end of the Deep Sleep period GPIO_16 goes low, pulling down the Rest Pin (Reset Pin is low active, eventually add 1-10k resistor in between) and restarting the Wemos.

Prolem is, that when ESP8266 goes into DeepSleep, all IO are goint go High – so my display is “on”. It will need an inverter.

SPI – Confusion

SPI did confuse me, it has 3 lines MISO, MOSI and clock, the same I found on the touch-display. At the end I realized that it has 2 controllers, one for the touch sensor, and the other one for the display. Both are connected at the the same SPI bus and are selected based on chip select. So it somehow looks like below:

SPI Logic on the TFT/Touch Display

Software – How to get it running?

I am using CLION from JetBrains and Platformio for development -what I can really recommend to do. The following libraries support both controllers:

Adafruit ST7735 and ST7789 Library
Adafruit GFX Library
XPT2046_Touchscreen

Thanks to this great libraries, below makes you paint on the little display with a pen, just some lines of code.

void setup(void) {
tft.initR(INITR_GREENTAB); // initialize a ST7735S chip, CN: My-chip has a "green flag at the protection foil"
tft.setRotation(1);
tft.fillScreen(ST7735_BLACK);
ts.begin();
ts.setRotation(0);

delay(500);

tft.fillScreen(ST7735_BLACK);
testdrawtext("Welcome", ST7735_WHITE);
delay(1000);
tft.drawPixel(150, 118, ST7735_GREEN);

}

void loop() {

if (ts.touched()) {
TS_Point p = ts.getPoint();
tft.drawPixel(p.y * x_tft_scale, p.x*y_tft_scale, ST7735_GREEN);
}
delay(5);
}

Mission completed 🙂