{"id":2083,"date":"2022-07-02T13:26:08","date_gmt":"2022-07-02T11:26:08","guid":{"rendered":"https:\/\/www.nerdiy.de\/?p=2083"},"modified":"2022-07-02T13:26:13","modified_gmt":"2022-07-02T11:26:13","slug":"evaluate-howto-raspberry-pi-mpr121-touchsensor-via-i2c-and-node-red","status":"publish","type":"post","link":"https:\/\/nerdiy.de\/en\/evaluate-howto-raspberry-pi-mpr121-touchsensor-via-i2c-and-node-red\/","title":{"rendered":"HowTo: Raspberry Pi - Evaluate MPR121 touch sensor via I2C and Node Red"},"content":{"rendered":"

Thanks to the I2C bus, the Raspberry Pi can be equipped with many practical sensors and actuators. A (in my opinion) very elegant possibility for user input is offered by the MPR121. <\/p>\n\n\n\n

The MPR121 is a controller that allows you to evaluate up to 12 touch electrodes. You can build up to 12 electrodes, which can then be used as buttons. Depending on the structure of the electrode, you can also detect these touches through thin materials or even just by approach (without touching).<\/p>\n\n\n\n

For example, I use this on my MagicMirror to manually turn the screen on and off. <\/p>\n\n\n\n

Everything you need to read out the MPR121 via NodeRed and to react on keystrokes can be found in the following article.<\/p>\n\n\n\n

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Safety instructions <\/span><\/h2>\r\n

I know the following notes are always kind of annoying and seem unnecessary. Unfortunately, many people who knew "better" have lost eyes, fingers or other things due to carelessness or injured themselves. Data loss is almost negligible in comparison, but even these can be really annoying. Therefore, please take five minutes to read the safety instructions. Because even the coolest project is not worth injury or other trouble.<\/span>
https:\/\/www.nerdiy.de\/sicherheitshinweise\/<\/span><\/a><\/em><\/strong><\/p>\r\n

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Requirements<\/h2>\n\n\n\n

Helpful articles:
<\/strong>So that you can install new nodes, NodeRed should of course already be installed.
How to prepare a RaspberryPi and then install NodeRed on it is described in the following articles.<\/p>\n\n\n\n

The following three articles describe what needs to be done to prepare the RaspberryPi:<\/p>\n\n\n\n