It's not a meter it's the weight. https://www.ebay.co.uk/itm/296376275808

 

I can now see my load cell working using the data from an HX711. Can I get a voltage out of the setup to operate a vco? I'm still having no luck with instrumentation amps. Thanks

Hi Steve,
Where in the circuit are you attaching the INA amps.
As you may know, the HX711 is a Bit stream output of the weight value, into an MCU input.

The only possible place in the circuit would be across the HX711 +/-A bridge inputs.

Post your INA circuit diagram.
E

 

I'm hoping to avoid using the HX711. I'm using it now just to confirm the load cells work. Initially I fed the 4 load cell leads into this: https://www.ebay.co.uk/itm/355843146919 with no result - I don't have a schematic for it. This worked right out of the box: https://www.ebay.co.uk/itm/225865048478 but may not have been sensitive enough.

 

Hi Steve,
Bottom line is, we need to see how you connected the LC to the modules in those links.
A simple sketch, showing the connections, would be sufficient
E

 

red to E+ Black to E- White to A- Green to A+

 

Would someone be kind enough to tell me how to wire 2 3 wire load cells? I've found instructions for 4 3 wire ones.

 

A "3-wire" load cell is also called a "half bridge" load cell, and it usually requires two BRIDGE COMPLETION resistors. I have no experience to draw on for advice about using them, and I am reluctant about guessing how to do it.

 

Found this on the web. Is it how you wire a single 3 wire load cell?

 

Hi Steve,
Yes, using 2 strain gauges.

E

Update:
Check Fig #3 on this PDF/
E

 

Thanks for that. Indrek Luuk on youtube has a pic which is exactly what I needed. Both load cells are working perfectly. Now I'd like to dispense with the HX711 and go back to my original plan to amplify the signal from the load cells. I now have the HX711 wired to the 2 load cells perfectly. How do I unplug E+, E-, A-, A+ of the HX711 and plug those wires into Vin, GND, -S, +S? What, if anything, goes where? Thanks.

 

I'd like to send the data from an HX711 (load cell) wirelessly to a phone (android) or computer (bluetooth?). What's the simplest way to do that? Thanks.

 

Probably making use of an ESP8266 or ESP32 board. Do you have programming experience?

 

Thanks. Not much programing, but I know someone who does. Also I don't require any dual role - only send. I assume I need a receiver and a maybe pi board.

 

Have a look at...
https://randomnerdtutorials.com/
They have some really good info.
On particular... https://randomnerdtutorials.com/?s=HX711

 

Thanks again. Is there a tutorial for then sending a wifi/bluetooth signal to a phone or linux computer from the esp32?

 

Yes.
Lots of stuff to help you.
https://randomnerdtutorials.com/?s=bluetooth

 

What about this for starters? https://www.ebay.co.uk/itm/135162141888 The receiver could plug into a Pi?

 

You will still need an Arduino or similar to read the HX711 and produce the serial data to send to the radio transmitter.
So, the RNT post using the Arduino Uno could be of use to you.
This is a good opportunity for you to get into the fun Arduino/ESPxxx field.

 

I can't send the output of the HX711 via the transmitter and input into an ESP from the receiver? https://www.ebay.co.uk/itm/135068941071

 

No. The HX711 needs a micro controller to drive it.