BIG diy SENSOR topic

(Wolfgang Klenk) #103

Indoor Air Quality (IAQ) Measurement with Bosch BME680 and STM32F103C8T6

In many LoRaWAN End Devices (Nodes) the STM32F103 aka “Blue Pill” is used as inexpensive microcontroller board. the Bosch BME680 is its ability to output an Indoor Air Quality (IAQ) using its built-in sensors for gas, pressure, humidity and temperature. Bosch Sensortec provides a software solution (BSEC: Bosch Software Environmental Cluster) that utilizes the 4-in-1 integrated sensors inside the BME680: This software solution provides an Indoor Air Quality (IAQ) index ranging from 0 to 500 which quantifies the quality of the air available in the surrounding.


It is a little bit tricky to get this software library running with the STM32F103 on the Arduino platform. I wrote down my experiences in this blog post:


for the arduino there is this development


SHT31-D Temperature and Humidity Sensor Module (I2C)



I bought some a few weeks back, that’s a very good price !




(Tvloon) #109

[ 15 - level switch ]



(Freedom2000) #112

Hacking a smoke detector :

(Gry Kyo) #113

I have also hacked a simple €10 hardware store smoke alarm with an ESP8266 to protect my home. I have CCTV, Wireless Switch and all the POE power and data for my TTN Gateway in the attic space. A fire could destroy the roof structure here before we would be aware so I built this.

There is a pin on the control IC of most smoke detectors to allow sympathetic alarming (such as in shared spaces of an apartment complex). I used this pin of the IC to drive the enable input of a mini buck converter which then generates the 3.3volt supply for an ESP01 module.
The ESP01 module boots, uses a static IP address to connect to my home router and pushes a message to our mobiles and Chrome extensions via Pushbullet. Total time from alarm to phone is circa 3-6 seconds and is 100% reliable so far in testing.

There is absolutely no technical reason why this could not be LoRaWAN. I chose the WiFi as it is slightly more persistent and to push a message involves less routing (fewer possible flaws in an already NOT fail-safe system).

The quiescent current (we love this number here!!!) of this system is only that of the detector circuit as the WiFi module is off unless the alarm is triggered.


(Gerardvtk) #115

I just started to test this camera and it works nice. But the output is like this:

[22.00, 23.00, 22.00, 22.25, 22.50, 23.25, 27.00, 26.00,
21.75, 22.00, 22.50, 22.25, 22.00, 23.00, 24.50, 25.75,
22.25, 23.50, 24.25, 22.00, 22.00, 22.75, 22.25, 24.50,
22.25, 22.25, 22.25, 22.25, 22.25, 21.50, 22.50, 23.25,
26.00, 21.75, 22.00, 22.25, 22.50, 22.75, 23.00, 25.25,
22.75, 22.25, 22.25, 22.25, 23.25, 23.25, 22.75, 25.75,
22.00, 22.25, 22.25, 22.50, 23.50, 23.50, 24.25, 25.75,
21.00, 21.25, 22.25, 22.75, 25.50, 25.00, 26.50, 28.50,

is that not too much data for sending to a gateway?


is water wet ? :wink:
do you really need that resolution transmitted…

(Gerardvtk) #117

this is the output from the demo sketch. it is my idea to use it to measure the plant temperature: detection of diseases, Etc. I have to think about it: maybe I can detect the temperature deviation for some of the pixels to generate an alert (flag =1 or 0). thanks water is wet but ice?


No and no.

Wet: Cover, touch or soak with liquid.

Water as a liquid can make objects wet but it is not wet itself, neither is ice.
When something wet becomes frozen, the water will become ice.
Ice is not a liquid, so when the water freezes to ice that object state should not be called wet.

However, ice covered with (unfrozen) water is wet, and so is ice covered with alcohol.

So is ice wet? It depends, but at least it can be wet (water cannot). :slightly_smiling_face:

(Gerardvtk) #119

Okay , thanks. back to my subject. I am playing with the thermal camera AMG8833. The simple sketch produces an array of 64 (8*8) datapoints. It was my idea to calculate an average and send that with a node, but I am not an arduino expert. Has anybody made already such a sketch to send data to a TTN gateway?


maybe its an idea to open a separate topic for that ?
I have seen the libs, think you need a bit of 'local processing ‘power’


This Walabot Starter version uses a three-antenna array to illuminate the area in front of it and sense the returning signals. The signals are produced and recorded by a VYYR2401 A3 System-on-Chip integrated circuit. They are then communicated to a host device (like your phone or computer) using a USB interface, which is implemented using a Cypress controller.

(Gerardvtk) #122

Soil sensor. Since a couple of weeks i work with the Soilwatch10 ( 3V) in combination with the Dragino mini dev. I made calibration ( With the WET sensor) for the volume soil moisture.


I did the search for you :wink:

maybe you want to write a story how to use and what your experiences are ?