The comfortable finger weight can be tested with a kitchen scale i guess. But have some headroom in your choice. That headroom protects your cell for abuse/accidents etc...
Analogue load cell amps designs are available on the net. Once you understand the Weadstone bridge priciple an opamp based diferential amp isn't too hard to find. choose an instrumentation opamp like the AD620 for now noise results and shield your housing very well.
I will create a topic soon and probably create all the files needed on github. Sorry for the quite late reply.
Analogue load cell amps designs are available on the net. Once you understand the Weadstone bridge priciple an opamp based diferential amp isn't too hard to find. choose an instrumentation opamp like the AD620 for now noise results and shield your housing very well.
I will create a topic soon and probably create all the files needed on github. Sorry for the quite late reply.
i dont know if you're open to it - but i think a few people would find this interesting - if you're open to it - would love to see some pics/explanation of the project in the DIY thread hereI recently made a 3-zone foot pedal (triangle with one cell under the heel and and top left and right pad for the top of your feet using 20Kg cells and HX711 loadcell amps and they work like a charm. I believe 1,5Kg would be too weak to handle abuse. I provided a rotary push encoder and lcd screen to set the parameters like midiCC number input and output range end so on. The HX711 scans at 80Hz so it is fast enough for expression but too slow for note triggering if you don't ignore the 12,5mS slop on the timing of the notes. Also the HW711 is 24bit so if you only need the first kilograms for finger operation there is still enough bitdepth for good expression. I provided a few functions you can set for each cell like program change, note with velocity, midiCC. I made a PCB containing an Atmega328, midi i/o, encoder, reset button and a connector for the 2 HX711 evaluation boards. The tarre goes automatically when booting the device.
What do you think would be a good weight for fingers? and also - is using a microcontroller necessary if wanting to make this but with a CV output? ie. is this something that could be achieved fully analogue? much like the doepfer ribbon is? Not because i dont think microprocessors are fast enough - more so from a simplicity standpoint.
Statistics: Posted by Troubleshooter — Wed Mar 27, 2024 6:05 pm
