Provides a simple dry-contact output assistive-technology button using a load cell, so that the force required to activate the button can be adjusted to suit the needs of the user.
The activation pressure can be adjusted by clicking the rotary encoder and then rotating the encoder. Clicking the button again applies the new setting and saves it in EEPROM. When it hasn't been clicked into adjustment mode, the rotary encoder is ignored so that it can't be accidentally bumped to a different setting.
The load cell reading is zeroed at startup, and can also be re-zeroed by pressing the "tare" button.
The output duration can directly match the button press, or it can be "stretched" to allow even a quick tap to cause a longer beep output. The beep stretching switch activates this option.
Features:
- 1 x input connection for a load-cell based button
- 1 x USB connection for power or to emulate an input device
- 1 x switched output (either N.O. or N.C.) to control other devices
- 128x32 OLED to show current force reading and activation threshold
- Rotary encoder to adjust activation threshold
- "Tare" button to reset zero point
- Pulse stretching feature controlled by slide switch
More information is available at:
https://www.superhouse.tv/superbutton
The "Hardware" directory contains the PCB design as an EAGLE project. EAGLE PCB design software is available from Autodesk free for non-commercial use.
The PCB called "SUPERBUTTON" is the main controller which is mounted in an enclosure.
The PCB called "SBCONN" is for the hand-held portion of the button, to make assembly easier and improve connection reliability. It includes a 4.2mm hole for placement of an M3 clinch-nut, which can be used to pass a travel-limit bolt through the PCB.
The "Firmware" directory contains example firmware as an Arduino project.
- Jonathan Oxer jon@oxer.com.au
- Chris Fryer chris.fryer78@gmail.com
Copyright 2019-2020 SuperHouse Automation Pty Ltd www.superhouse.tv
The hardware portion of this project is licensed under the TAPR Open Hardware License (www.tapr.org/OHL). The "license" folder within this repository contains a copy of this license in plain text format.
The software portion of this project is licensed under the Simplified BSD License. The "licence" folder within this project contains a copy of this license in plain text format.