After dropping off the switches with Monique for the first time to test using them long term, she started having issues after 1 week. I finally got around to fixing the issue in August, 2019.
August 11, 2019
Issues:
- A minor issue was that a cover had come off. This is because the fabric used for the cover is not cut large enough in diameter and only stretches one way. It pulls out easily from the frame because of these two things.
- Cables are a large issue. It would be great to create a mat with embedded buttons for her. It takes so long to untangle the switches from each other every time I transport or move them around.
- The LED came out of the enclosure.
- SW switch is stuck on. I can visibly see the tiny curl to one of the corners of the rect/silicone switch which was keeping the switch closed.
- Up is stuck on. Unsure where it was stuck but my hunch in near the bottom where the lead gets bent down towards the frame.
I was interested to know if the stuck switches were of the older interdigitated design with netting as the spacer, or the newer two contact design with siliconet spacer. I took stock of what I had.
Up – inter/net
Right – inter/net
Right-click – inter/net, medium size
Left-click – inter/net
On/Off – inter/net with ShieldIt conductive fabric (very old design!)
Left Lock – inter/net with ShieldIt conductive fabric (very old design!)
SW – rect/silicone
SE – inter/net
NE – rect/silicone
NW – inter/net
Down – inter/net medium
Left – inter/net
After I took the stuck switches apart they released and worked as normal. Since each of the switch types got stuck, I feel like I need a totally different approach to the switch design.
Another observation is that the inter/net switches take different amounts of pressure to activate which was not designed. The rect/silicone design so far takes the same amount of detectable (human detection, I am not measuring using any special devices) force to activate.
FSRs as switches
I’m going to take this opportunity to replace the switches with FSRs that are pressure activated (silicone spacer). The pressure of the fabric stretched on top, however, keeps the FSR activated. Still, I believe this is still a good time to test them as switches. I currently have two made from the “pressure-activated sensors” tests using: .1 ” thick silicone
3 mm hole diameter
5 mm hole spacing
Reading with a pull-up on the analog pin of a Teensy 2.0 it hovers around 450 once in the switch frame.
Final Solution
August 21, 2019
The Teensy 2.0 I am currently using has limited analog pins. I was able to replace 4 switches with FSRs.
Up – inter/net
Right – inter/net
Right-click – inter/net medium
Left-click – inter/net
On/Off – inter/net with ShieldIt
Left Lock – inter/net with ShieldIt
SW – FSR
SE – FSR
NE – FSR
NW – FSR
Down – inter/net medium
Left – inter/net
I plan on giving it back to Monique as is to see if other defects can be shaken out and to test the FSRs, however, I am planning to use a Teensy 3.1 or 3.2 for the next iteration which will give me enough analog pins to replace all of the digital switches with FSRs.