The small 128 × 64 OLED display offers good readability even in bright light. It does not consume a lot of energy and seems ideal for outdoor use. Associated with a pressure sensor BMP180 module, it’s relatively easy to achieve a very compact altimeter for hiking.
Orginal project link: +https://keeptronic.wordpress.com/2017/01/09/tiny-altimeter/
Parts:
Mini 1A Lithium Battery Charging Board Charger Module $1.30
Video review: https://www.youtube.com/embed/mMiMNTv25Bw