After implementing the Android app for FIDO2 authentication [/05.08.2019/some-progress-with-webauthn/] I started to implement the same functionality on the ESP32 development board.

> Buy the CH340G programmer for ESP8266/ESP32 > [https://www.tindie.com/products/thinkingthing/usb-programmer-for-esp8266esp32/] > online

Last (and previous) weekends I've spent on the real implementation of FIDO2 WebAuthN protocol. In reality, the problem is more deep and difficult than I was thinking before, so I have re-implemented the GATT server on Android to have higher-level language and libraries and better debugging capabilities.

A few days ago I have taken part in the discussion on Reddit about displaying JPEG image on black and white e-ink screens attached to the ESP8266 MCU. The original poster asked how to use external service to convert RGB image into dithered black and white one.

Last weekend I could play with the ESP32 board to implement BLE transport for FIDO2 WebAuthN protocol. The great BLE library for Arduino [https://github.com/nkolban/ESP32_BLE_Arduino] and tutorials [https://circuitdigest.com/microcontroller-projects/esp32-ble-server-how-to-use-gatt-services-for-battery-level-indication] helped me a lot. Now my developer board advertises itself as FIDO2 Authenticator and provides four required endpoints to communicate. Google Chrome is able to detect the device and tries to connect to it which I consider as a great success for the weekend project. However, the endpoints just do nothing at the moment and authentication fails with an error.

Some time ago I was reading news and met a very interesting topic — password-less authentication. The idea is great: instead of remembering multiple passwords for the different websites one could use a special device called Authenticator which will cover all registration and authentication processes using modern cryptography and biometric technologies.

While working on a CO2 sensor [/10.06.2019/carbon-dioxide-sensor-mh-z19b-part-1/] I needed to manage the device without any human interface or additional connectors. Fortunately, the ESP8266 devices include the WiFi interface and it was obvious step to use it for device management.

Some time ago I have purchased online carbon dioxide (CO2) sensor module MH-Z19b. It's a cheap and very simple sensor with the UART interface allowing concentration measurement in the range up to 5000ppm.