Week’s Accomplishments:

Tested soldering the copper wire thread to components. Seemed to work really well. Didn’t even burn the fabric too much!

 

 

 

Here is a close up of the wiring and solder connections. The wires are really small!

 

 

 

 

Copper taffeta from LessEMF. Nice stuff and the shipping was faster than I expected.

 

 

 

Close up of the taffeta. The conductivity is good across the surface, so hopefully this will be useful for a variety of tasks.

 

 

 

Both Teensys are plugged into the breadboard with SD-card slots. All we need now is the transmitters and we can get some communication happening.

 

 

 

Screenshot of the VCard loading from SD chip and then the SipHash running on it to generate a 64-bit hash code. Should be strong enough to avoid collision, while being short enough to transmit really fast for identification.

Problems:

No serious problems apart from waiting for parts.

Successes:

Hash code went smoother than expected. Discovered SipHash, a fast hash developed to resist collision attacks on hash tables. Not as safe as something like SHA1, but really fast for a micro-controller to perform (350 us!) and certainly suitable for a small scale prototype. Overall I’m quite pleased with it.

Schedule:

Starting to run behind I think, due to the delay on the RF transmitters. But the shielding fabric is in, so when I get them, I can start testing with that immediately.

Next week:

Hope and pray the transmitters arrive early, so I can figure them out by end of the week. There is a shipping notice, so here’s me hoping.