You might have realised that I’m recently into scales and load cells. So I couldn’t help but trying to build my very own Wifi body scale. Since the ones from Withings easily can cost $150 my goal was not only to build one myself but to build one on the cheap. And I could build one for less than $30!
Ok, up to now it doesn’t have quite the features that the Withings scale has but some of them (weather info) I have already incorporated into ESP8266 projects. So be warned, this is only the beginning!
Ok, up to now it doesn’t have quite the features that the Withings scale has but some of them (weather info) I have already incorporated into ESP8266 projects. So be warned, this is only the beginning!
I’m currently in the process of documenting the whole project, so hopefully in a short time I will be able to upload the code and add some more pictures.
Current features
- Get profile name from runkeeper.com
- Weight until stable reading > 10kg then post to runkeeper.com
Planned features
- Display weather information
- Built in battery
- Multiple user detection
- Display BMI, last weight
- Use simple light resistors to detect swipes with foot (touchless control)
Shopping list
- Super cheap body scale (for Swiss readers: I bought mine from Coop): ~$9
- NodeMcu V1.0 from Banggood: ~$8
- HX711 ADC from Banggood: ~$1.80
- OLED display 128×64 from Banggood: ~$6
- Optional: Power Bank from Banggood: $~13
This is cool. How do you interface to the load sensors? Is the firmware NodeMCU?
I was really lucky since the scale had an only lightly connected PCB where all the load cells would be soldered. I only had to detach this PCB from the main PCB and connect it to the HX711. Connecting the HX711 was then straight forward… The firmware is Arduine IDE based. I hope to publish it soon…
For inspiration, SparkFun has nice board/circuit for combination of four load sensors to connect to HX711 and similar. https://www.sparkfun.com/products/13281?_ga=1.107906887.496881665.1430488495
Can you please upload your code incl. runkeeper-api to your github?