Getting more from a digital bathroom scale

January 21, 2019

getting-more-from-a-digital-bathroom-scale  Facebook  Twitter  Google +  

This idea was in my mind since decades but just don't want to waste a whole arduino for a single i/o operation which draw less than 2watts.

Recently discovered digispark which is an ATtiny85 powered development board costs around $5. It's smaller than arduino pro mini which makes it perfect fit for wearables and iot projects.

There is already wifi/bluetooth enabled bathroom scales available on the market but they're expensive and only sending data to their own application with a custom protocol. My setup costs around $10 and took one hour to deploy. It's collecting sensor values from hx711 load cell amplifier and transferring this information to pc with 443mhz wireless link. I attached a wireless receiver to previously mentioned sensor station which collecting the data and pushing it to my virtual assistant software called Judith

How is the data processed
I created a script that groups the same values in array and deciding the gross value by getting value of largest group. Previously i tried to take average of incoming data but this method provides more accurate readings.

Virtual assistant writing that value to database and providing voice feedback after that. Also created a JSON api endpoint for chart visualization purposes.

Assistant software is mostly turkish, planning to release it to public after a translation and some makeup but you can take a look to arduino sketch if interested with creating a similar setup.

Shopping list
+ Bathroom scale - $8
+ hx711 load cell amplifier - $2
+ digispark dev board - $3
+ 443 mhz transmitter - $1

arduino compatible source code available in here:

  Most popular entries

VR Experiences #1: Oculus Rift

The 80's childs are familiar with virtual reality term. we seen this subject in the action at johnny mnemonic, the lawnmowerman etc.if you're not living in a cave, probably should know the

Stealing sneakers from NIKE

as the whole crafty geeks knows, nike has a rvsp system via twitter. they

Bytecheleby at revision

Looks like our portable shell "Bytecheleby" still useful on scene. im started to enhance it by using my newest libraries and lots of new stuff. stay connected for latest releases

Pain and Suffer inside: Displaylink Adapter

as mentioned on my recent tweets, was looking for a low cost multi-display solution about couple weeks. gaming oriented gfx cards already

Entering system level command line

I get this trick from a sysadmin friend. it allows to enter system level shell access in Windows Vista and later versions. useful for bypass UAC and ntfs file permission create SuperC