Scale testing and current state of affairs
It took me a while, thanks to some other projects I ended up focusing on in September-October, but I finally got a full-size prototype built.
On the one hand, the mechanical design seems solid. The platform is 14” wide, which should accommodate any fermentation vessel under the 30ish-kg capacity of this load cell combination without much trouble, without being too large to fit into a fermentation freezer.
On the other hand, the electrical design has been causing me fits. Either I have one or more bad load cells, or my connector crimping is not up to snuff and I have one or more bad connectors, or I’ve been misled on the ease of connecting load cells in parallel.
My present to-do list is four steps:
- Write a scale-test function for the PCB firmware, which keeps the HX711 powered all the time and reads its output constantly, without much averaging.
- Connect each load cell individually to the PCB via jumper wires or jumper wires+breadboard, and verify that each one works individually.
- Assuming 2. shows four good load cells, re-crimp connectors for each load cell, perhaps with a dot of solder or a bit of solder paste, then verify that each load cell still works with the connector.
- Reassemble everything and see what happens.
I’ll report on my results as they happen.