The Picoclick is a tiny device which can be used as an IOT-Button. It is a one-button-device which let's you control different stuff in your smart home or the internet of things. A basic example is to toggle a light bulb by a button press. Moreover the Picoclick-C3 can be used as a mini development board, because it comes with an FPC extension port where other hardware can be connected to.

Note: This GitBook is a work in progress. You will notice that some points are rarely explained but this will be completed in the next few days. There will be a little software guide as well.


This video explains at least the most important parts of the Picoclick project. Furthermore it shows the whole Picoclick evolution and the assembly process. There are a few examples in the end of the video - including the motion extion board. There will be a second episode with the other upcoming extention boards.

The new video shows different kind of extension boards and what they can be used for. Furthermore it shows the integration of Picoclick devices to Home Assistant with using ESP-NOW.


This device is able to connect to a WiFi network and perform a task, such as sending a message or writing to a topic (MQTT). The connection setup to your access point takes some time (about 2-3 seconds) which is too much for some applications - at least for me it is. Therefore I'm always using my Picoclicks with ESPNOW which is a WiFi protocol developed by Espressif itself. It doesn't need a connection to an access point and thus the communication is ultra fast. Nevertheless when using the ESPNOW protocol there need to be a bridge (ESP based device) converting these messages into MQTT messages for example.

Operation principle

The Picoclick is a ultra low power device - it can shut off its own power supply by software and consumes only about 2µA while inactive (which is only due to the embedded battery protection). The so called power latching circuit is able to manage the enabling of the voltage regulator. This can be done in two ways:

  • The button. When pressing the button, the voltage regulator will be enabled and thus the device will get activated.

  • The latch. A GPIO or any other output of the processor.

For previous versions of the Picoclick I have choosen a normal GPIO of the processor. When the button is pressed, the processor will boot and its first task is to fire the latch which will hold the power supply of the device. If the device should shut down, the latch can be grounded and the power supply will get disabled. This ensures that the processor is fast enough to fire the latch - else the device would shut down without any operation.

And here is the golden point of the Picoclick-C3. It doesn't use a GPIO for the latch, but the power supply signal of the embedded flash. Regarding to the datasheet of the ESP32-C3 that supply will be deactivated during deep sleep of the processor to save some power. Furthermore this power supply will be immediately present after the processor will be powered. So to deactive the Picoclick device it is only necessary to enter deep sleep mode. (Just to be sure: The device will not go into deep sleep mode because it looses power beforehand)

Apart from this you don't have to struggle around with the latch in your software and you don't have to configure the ESP32-C3 to be as fast as possible as well (like the C3T). Therefore there is no need to use the ESP-IDF to flash the Picoclick anymore. The Arduino framework will work perfectly with the device as well.

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