Published December 24, 2018 © LGPL

Kniwwelino Controls a BME280 via I2C

Using the Arduino IDE, a short sketch is enough to query a BME280 sensor with the Kniwellino to get temp/humidity and more details.

BeginnerShowcase (no instructions)1 hour805

Things used in this project

Hardware components

Kniwwelino

SparkFun Atmospheric Sensor Breakout - BME280

or cheap alternative via I2C

Jumper wires (generic)

4 pieces

Li-Ion Battery 1000mAh

optional for mobility use

Story

If you are not yet familiar with the Kniwellino device, you will find in this article a short introduction with the necessary craft stuff.

Why only check the weather with a BME280 sensor? Just put the fridge on and the Kniwwelino with the sensor inside - wait well - check fridge temperature (5 centigrade) with your measurement after (7.40 cenitgrade). Finished!

LiPo left, Kniwwelino mid and BME280 sensor right

In addition to the typical BME280 information such as temperature, humidity and air pressure (height information omitted), a timestamp with date is also output on the integrated matrix.

Preparation

For this to succeed, a few steps of preparation are needed. First of all: Under Blockly, the I2C address (0x76) for the sensor is fixed. A change like in my case, is only possible via the Arduino IDE.

Check I2C address

So check before deciding whether Blockly or Arduino IDE has which I2C address your sensor has (link to an I2C scanner) and match it with the Kniwwelino docu.

Install Board & Libs

Now prepare the Arduino IDE with the necessary libraries once. Go for the most part as described here. Note that the information shown does not correspond to the most recent versions.

Since the Kniwwelino belongs to the family of ESP8266 devices, insert the link as indicated and do not orient yourself on the screenshot.
Type ESP into the search box of the Boards Manager window and not "kni" (for Kniwwelino).
use the WeMos D1 and set the Flash Size to 4M (3M SPIFFS) or with Arduino IDE 1.8.5 you can use Lolin (WeMos) D1 R2 & mini.
Installation of all necessary libraries

The following libraries are required to use the Kniwwelino Arduino Library:

Adafruit GFX Library v1.2.2 https://github.com/adafruit/Adafruit-GFX-Library
Adafruit NeoPixel v1.1.6 https://github.com/adafruit/Adafruit_NeoPixel
ArduinoJson v5.11.1 https://github.com/bblanchon/ArduinoJson
MQTT v2.3.1 https://github.com/256dpi/arduino-mqtt
WiFiManager v0.12 https://github.com/tzapu/WiFiManager.git
Time 1.5 https://github.com/PaulStoffregen/Time
TimeAlarms 1.5 https://github.com/PaulStoffregen/TimeAlarms
Timezone 1.1.1 https://github.com/JChristensen/Timezone

The example offered for the BME280 was probably programmed at night under the influence of lack of time ;-) and does not work right away: in addition to the fixed I2C address, there is still a small typo error in it and in principle little was documented. The map-command is here explained. If you look over it and look at the Kniwwelino library, you will quickly learn about other commands, such as using the timestamp with Kniwwelino.getTime(). A real time component is not included: rather, the time stamp is retrieved via NTP.

So I let myself be guided by the example and came to my code in the attachment.

at least I added a timestamp

Put all your components in this 3D printed box. Not tested.

Code

Kniwwelino works with BME280 via I2C

/***************************************************

  Kniwwelino BME280

  Ingo Lohs, v1.0

  Example sketch for using an Bosch BME280 Sensor connected via I2C.

****************************************************/

#include <Kniwwelino.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BME280.h>

Adafruit_BME280 bme; // I2C

void setup() {
  Kniwwelino.begin(true, true); // Wifi=true, Fastboot=true
 
    bool status;
    status = bme.begin(); // 0x76
    if (!status) {
        Serial.println("Could not find a valid BME280 sensor, check wiring!");
        while (1);
    }
    delay(1000); // let sensor boot up
}

void loop() {

    if (Kniwwelino.MATRIXtextDone()) {
          Kniwwelino.MATRIXwriteOnce(String(bme.readTemperature()) + "C" + " -:-:- " + bme.readHumidity() + "%" + " -:-:- " + (bme.readPressure() / 100.0F) + "hPa" + " -:-:- " + Kniwwelino.getTime()); // time+date   
    }
    Kniwwelino.sleep(2000);
}

Credits

Ingo Lohs

182 projects • 198 followers

I am well over 50 years and come from the middle of Germany.

Contact

Comments

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Kniwwelino Controls a BME280 via I2C

Things used in this project

Hardware components

Story

Preparation

Check I2C address

Install Board & Libs

Schematics

Kniwwelino works with BME280 via I2C

Code

Kniwwelino works with BME280 via I2C

http://github.com/LIST-LUXEMBOURG/KniwwelinoLib

Credits

Ingo Lohs

Comments

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Kniwwelino Controls a BME280 via I2C

Kniwwelino Controls a BME280 via I2C

Things used in this project

Hardware components

Story

Preparation

Check I2C address

Install Board & Libs

Schematics

Kniwwelino works with BME280 via I2C

Code

Kniwwelino works with BME280 via I2C

http://github.com/LIST-LUXEMBOURG/KniwwelinoLib

Credits

Ingo Lohs

Comments

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