TEK G2 is three body worn bands (waist belt, collar strip, two ankle bands) carrying 20 coin LRA actuators, a sensor head at the waist, a two processor electronics core, and the wearer's own smartphone on a chest mount. Distance to the world is measured, fused, and pressed onto the skin as vibration. No interpreter and no voice in the warning path.
Actuator allocation: 8 on the waist belt, 4 on the collar strip, 4 on each ankle band. Total 20.
Signals in the first build: obstacle left, center, right at the belt; head height at the collar; stairs up and stairs down at the ankles.
Placement sources: 30 mm trunk spacing, eight belt motors, one head channel, four motors per readable stroke, from Cholewiak, Brill and Schwab (2004) on abdomen localization, van Erp et al. (2005) on the vibrotactile waist belt, and Bach-y-Rita on sensory substitution. Cholewiak reported about 92 percent correct localization with eight tactors around the torso, near perfect at the navel and spine, so belt zones are anchored to those landmarks.
Architecture in one line: sensors to the Reflex (RP2350) to drivers to motors is the warning path; the Reflex sends a one way copy of its state to the Spine (ESP32-S3), which talks to the phone over Bluetooth; the phone runs the camera, the assistant, and the text home, and can never write into the warning path.