Weight Sensor

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Hello Community,

for a project I need a (wireless) weight sensor, that could be read by pimatic. Max load would be 5kg. Accuracy should be at least 100g.

Are there any known devices?

@SaxnPaule I think you can use a HX711 24-bit ADC for weight sensors along with a suitable load sensor. The HX711 should be fairly to read and program. When you google for it you will find code samples for raspi, arduino and esp8266. Unfortunately, it is does not appear to be supported by espEasy or johnny-five. So, some work is required to integrate it to pimatic.

• https://cdn.sparkfun.com/datasheets/Sensors/ForceFlex/hx711_english.pdf
• http://www.phidgets.com/products.php?product_id=3133
• http://www.instructables.com/id/Make-your-weighing-scale-hack-using-arduino/ - describes a hack to provide an interface to an off-the-shelve weighing scale.

Most likely not accurate enough but worth a try

Wii balance board

https://www.stavros.io/posts/your-weight-online/
https://github.com/aelveborn/Wii-Scale

Up to 3 kg, you are you could use this:
http://www.aliexpress.com/item/Weight-Sensor-Kit-3KG-For-Arduino/32263159886.html

This library should not be difficult to make it work on ESP8266.
https://github.com/bogde/HX711

For example, as an extension ESPEasy. Can you come out example of this plugin:
https://github.com/ESP8266nu/ESPEasyPluginPlayground/blob/master/_P100_SRF01.ino

Or create a simple sketch, who send data to Pimatic API or over MQTT protocol.

this is kinda old thread, and there is only 5 days left on this campaign - but others who find the thread later may find it interesting and seek out the weightz after the kickstarter.

https://www.kickstarter.com/projects/biophobe/weighitz-weigh-smarter

I’m getting one, and hoping they’ll provide bluetooth broadcasts that can be used by any software.

I used an adapted (wiring pi) HX711 version with two 5kg load cells.
The script writes the values to a log file continuesly. The script runs with nohup in the background.

Everytime the load is below 10g, the weight sensor calibrates itself to avoid temperature related deviations.

Within pimatic I use a shell sensor that uses a tail -1 on the log file to get the value into pimatic and broadcasting it via MQTT to the broker.

Have a look at our company blog: http://www.bigdata-unleashed.com/20160922/der-intelligente-kaffeesockel

There you can see how the sensor works. The use of Pimatic and the data visualization via Kibana will be shown in the next article.

The idea behind this setup is described here: http://www.bigdata-unleashed.com/20160609/iot-use-case

i’ve ordered some of this sensors

http://m.ebay.at/itm/4-pcs-50Kg-Body-Load-Cell-Weighing-Sensor-Resistance-strain-Half-bridge-Total-/161350037714?nav=SEARCH

lets see what i ca do in combination with mysensors when they arrive

i want to build a component for my alarm system in the lower construnction of my terrace-floor to send a signal to pimatic if the load-weight was greater than 25 kilo

@SaxnPaule
wow! that’s a very nice project!
am curious about the pimatic part

@xCite86
that’s a very interesting and cool project!
am curious about your findings too
maybe you should open a new hardware thread for this project if you want to share it with us…

Really cool project, need to propose this here also we have the same coffeepots here.

that’s a very interesting and cool project!
am curious about your findings too
maybe you should open a new hardware thread for this project if you want to share it with us…

yes, sure… i will do if they will work

i have to say the inventor for this project was my dad. he’s afraid of burglaries coming from the east… so he asks me for a device like that

Today the blog post regarding the visualisation was published: http://www.bigdata-unleashed.com/20161011/iot-use-case-visualisierung-und-datenauswertung