Repeatability and accuracy of the old scale is very poor. Around 1 or 2 lbs. Resolution is also only 0.5 lbs so I decided to make a better one that includes automatic recording to a graph in the cloud. It's repeatable to within 0.1 lb. Returning to exactly zero is not a problem at all either. Impressive. It's calibrated with my weight using the doctor's scale.It's made from a $4, nice looking, warm on the feet, dollar store bamboo cutting board. The slot for the display already existed.I used a bright, hi-res OLED display instead of a low-res LCD. The onboard NodeMCU blue LED is used as a night light under the scale. A photoresistor in a voltage divider circuit connected to analog input AO is used to turn on or off the night light and also initiates the OLED display routine when the bathroom light is turned on in the morning. OLED display turns off when it times out or bathroom light turned off. A USB charger is used instead of batteries to power it.
https://www.youtube.com/watch?v=RtXzMJhcsJQ
https://hackaday.io/project/182014-wifi-bamboo-bathroom-scale
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