The shield SD board reader for WeMos d1 mini will allow you to make small data loggers very easily. You can add a Shield Battery to operate the WeMos on a LiPo battery.
Arduino connection and code
The Shield microSD uses 4 pins of the ESP8266 (D5, D6, D7 and D8) to operate. A sample code is available from the Arduino IDE or from GitHub here.
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Micro SD Card Shield For WeMos D1 Mini TF WiFi ESP8266 Compatible SD Wireless Module For Arduino For WeMos D1 Mini
|Current Price||CHF 0.56||10 August 2022|
|Highest Price||CHF 0.58||21 September 2021|
|Lowest Price||CHF 0.56||25 August 2021|
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|CHF 0.56||10 August 2022|
|CHF 0.57||3 August 2022|
|CHF 0.58||16 March 2022|
|CHF 0.57||16 February 2022|
|CHF 0.58||7 February 2022|