added espenv project

input/blog/2015/2015_12_30_caselights.md

 title: Blog
 post: CaseLights
+description: RGB LED / UV light controller with Arduino for Linux and Mac
 comments: true
 flattr: true
 github: https://github.com/xythobuz/CaseLights
 
 You can find all Arduino and Mac code in the [CaseLights GitHub repository](https://github.com/xythobuz/CaseLights).
 
+In August of 2019, I also added a Linux version of the host control software, as a PyQt status bar app.
+The code for that is in the repo as well.

input/projects/espenv.md

+title: ESP-Env
+description: ESP32 / ESP8266 & BME280 / SHT2x sensor with InfluxDB support
+parent: projects
+github: https://git.xythobuz.de/thomas/esp-env
+date: 2020-01-06
+update: 2020-10-22
+---
+
+As a first step into smart home automation, I wanted to place temperature and humidity sensors in most rooms of my flat.
+To achieve this, I made some simple ESP8266 boards with an I2C sensor, either SHT21 or BME280, as well as a small 3.3V regulator and a USB connector.
+The data is written into an InfluxDB instance on my NAS.
+
+<!--%
+lightgallery([
+    [ "img/espenv_10.jpg", "BME280 bedroom, front" ],
+    [ "img/espenv_17.jpg", "SHT21 kitchen, front" ],
+])
+%-->
+
+The web interface implemented to query the sensor data is very simple.
+I am using the following commands to fetch it.
+
+    curl --silent -m 10 esp-livingroom | grep -E 'Location|Temperature|Humidity' | sed 's/Temperature//g' | sed 's/Humidity//g' | sed 's/Location//g' | sed '2s/$/ \xc2\xb0C/' | sed '3s/$/ %/' | sed 's/: //g' | sed '$!N;s/\n/\t/' | sed '$!N;s/\n/\t/'
+
+The result is shown on my desktop using [conky](http://conky.sourceforge.net/docs.html).
+
+<!--%
+lightgallery([
+    [ "img/espenv_screen.png", "Screenshot of web interface" ],
+    [ "img/espenv_desktop.png", "Screenshot of desktop data" ]
+])
+%-->
+
+Here you can see some samples of the data I have logged since starting this project.
+As you can see, after a while the sensor in the kitchen started giving wrong data.
+This is the usual behaviour these sensors show after a couple of months to years.
+I replaced it, but shortly afterwards removed the kitchen sensor completely.
+You can also see some short gaps in the data, this is caused by the ESPs losing their WiFi connection after a while.
+I just had to reset them and they started working again.
+
+<!--%
+lightgallery([
+    [ "img/espenv_1.png", "Humidity data from ca. 7 months" ],
+    [ "img/espenv_2.png", "Temperature data from ca. 7 months" ]
+])
+%-->
+
+Here are some more photos of the PCBs I made.
+All of the boards, except one, work fine.
+The non-working one is just not connecting to WiFi, regardless of which specific ESP8266 I plug in there.
+I have no explanation for this, unfortunately.
+
+<!--%
+lightgallery([
+    [ "img/espenv_3.jpg", "BME280 livingroom, front" ],
+    [ "img/espenv_4.jpg", "BME280 livingroom, front bare PCB" ],
+    [ "img/espenv_5.jpg", "BME280 livingroom, back" ],
+    [ "img/espenv_6.jpg", "SHT21 bathroom, case" ],
+    [ "img/espenv_7.jpg", "SHT21 bathroom, front" ],
+    [ "img/espenv_8.jpg", "SHT21 bathroom, back" ],
+    [ "img/espenv_9.jpg", "BME280 bedroom, case" ],
+    [ "img/espenv_11.jpg", "BME280 bedroom, back" ],
+    [ "img/espenv_12.jpg", "BME280 storage, front" ],
+    [ "img/espenv_13.jpg", "BME280 storage, back" ],
+    [ "img/espenv_14.jpg", "non-working, front" ],
+    [ "img/espenv_15.jpg", "non-working, back" ],
+    [ "img/espenv_16.jpg", "SHT21 kitchen, case" ],
+    [ "img/espenv_18.jpg", "SHT21 kitchen, back" ]
+])
+%-->
+
+The source code can be found [on my Gitea server](https://git.xythobuz.de/thomas/esp-env).
+
+## License
+
+    ----------------------------------------------------------------------------
+    "THE BEER-WARE LICENSE" (Revision 42):
+    <xythobuz@xythobuz.de> wrote this file.  As long as you retain this notice
+    you can do whatever you want with this stuff. If we meet some day, and you
+    think this stuff is worth it, you can buy me a beer in return.   Thomas Buck
+    ----------------------------------------------------------------------------