Read 4 or more load sensor with I2C interface

Projects General Guidance
21

It could be

Arduino ----1m or less----MUX0----5m----HX711_0    bee-hive 1
                          |----5m----HX711_1    bee-hive 2
                          |----5m----HX711_2    bee-hive 3
                          |----5m----HX711_3    bee-hive 4
|-----------1m or less----MUX1----5m----HX711_4    bee-hive 5
                          |----5m----HX711_5    bee-hive 6
                          |----5m----HX711_6    bee-hive 7
                          |----5m----HX711_7    bee-hive 8
|-----------1m or less----MUX2----5m----HX711_8    bee-hive 9
                          |----5m----HX711_9   bee-hive 10
                          |----5m----HX711_10  bee-hive 11
                          |----5m----HX711_11  bee-hive 12
|-----------1m or less----MUX3----5m----HX711_12  bee-hive 13
                          |----5m----HX711_13  bee-hive 14
                          |----5m----HX711_14  bee-hive 15
                          |----5m----HX711_15  bee-hive 16

A position like this:

                          MUX2
                           |
                           |
                       1m or less
                           |
MUX1-----1m or less-----Arduino----1m or less-------MUX3
                           |
                           |
                     1m or less
                           |
                           |
                          MUX4
22

Each HX711 is connected to a 300kg load cell (4 wires) like :
https://fr.aliexpress.com/item/1005001854434627.html?spm=a2g0o.order_list.order_list_main.94.74e65e5b5mZ2v3&gatewayAdapt=glo2fra

23

The link does not work

image
image2121×636 50.1 KB

24

Sorry.
This type of load cell :

Capture du 2023-09-04 13-25-14
Capture du 2023-09-04 13-25-14921×918 338 KB

25

Are you sure that your bee-hives have a weight of 200 kg?
The higher the maximum-load the lesser the resolution you have.

You haven't written yet what the purpose of measuring the weight is.

If I start to speculate: how many bees are outside at what hour and how much nectar is brought in per hour / per day. I guess for measuring this te resolution should be pretty high

26

A beehive can weigh 140kg without any problem... And to load the beehives on the pickup without removing the scales, it's 250kg on each scale.
A precision of 100 or 200g is sufficient.
Measuring the weight is interesting for:

  • how much nectar enter in a day
  • if the colony have enough food
  • if it's time to put a hive rise
  • if it's time to take honey
  • put more beehives on this apiary
  • move beehives from an apiary to an other with more nectar
  • ...

without take your car, take time to go and comeback...

27

For 16 loadcells with 16 HX711s, you only need 17 wires, one for PD_SCK and one DOUT for each HX711. You could use an ATmega2560

28

Not sure that is going to be possible.
Good quality scales for weighing people have that level of accuracy, but to achieve it requires a zeroing step (tare) where you unload the scale and set the zero point before stepping on the scale and taking a measurement. This step compensates for drift due to temperature changes etc. and has to be done before each reading.

Unless you have a remote controlled mechanical way of temporarily lifting the hive off the load cells then you'll only be able to do the zeroing step when you visit the hive. In the intervening period the measurements will drift so you won't know if you are seeing real numbers or not.

29

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.