A project to weigh a worktable

Using Arduino Sensors
1

Good morning

i'm the last of newbie on this forum and for Arduino too.. Some years ago my dad teaches me how to do a circuit board for a stroboscopic light but next my experience with electronics is ended 'cause my work is another.. Now for passion and a project i'm intrested to understand more about this, i've buyed an arduino and i want to share with you my project, my idea, in order to have some directions about how to do that..

Maybe somebody of you knows is something like that has just been done and/or how to do that..

My need is to weigh the total load of a table with all the things that are settled on that continuosly in the time, i need the data of the total weigh each 30 second in a time range of 10 hours.. I need this datas both saved in a excel table (ok csv) and both displayed "Real time" (ok the last data each 10 seconds).

This table have 4 foots!

Have you got some ideas about that?

2

What size and weight is the table?
What weight range?
What accuracy?
What resolution?
What sensors?

Give us as much information as you can.

Weedpharma

3

Hi weedpharma, i havent explain this thing 'cause i was thinking that is unnecessary 'cause was only a proble of type of sensors.. But ok, i was wrong.. :slight_smile:

The minimum weight that they sense in total is circa 30 kg, (that is the weight of the table) the maximum is circa 150 kg but if the table is "blocked" and his weight equally distribuited, the load on that can be a lot on one foot 'cause not all the things are in the center of the table. So i think that i need 4 sensors that understand each one a load between 5 and 100 kg with the accuracy of 0,1 % (0,1 kg on 100 kg).

Is ok?

4

You would need each sensor to be able to measure the max load as it could all be on one corner.

I have no experience in measuring weights but others may be able to help with this info.

What programming experience do you have? Recording to a spreadsheet is not a simple project for beginner.

Weedpharma

5

Ok, thanks! I haven't experience on that, i was searching for some just-done parts to be composed..

6

What have you found so far? See item 4 in the "how to use this forum" post.

7

Hi Dave, i've searched but i'm not so able to do that.. What you suggest to search?

8

You want an HX711 module and four load sensors. These parts are very common; shop around for the best deal.

The four load sensors at 50kg each would allow a total table and "stuff" weight of 200kg.

See this Sparkfun HX711 tutorial for how to hook them up. As applicable to your table you'd be placing one load sensor under each leg of the table then wiring them in pairs to form a wheatstone bridge. The HX711 has two channels, one for each pair. You would read the weight of each bridge/channel then add them together for the total weight.

You will need to calibrate everything, of course, but the values from the HX711 should be reasonably linear with the weight on the table.