Cane demo

This page is a bench demo for a standard iPhone 16 with the Bluefy app, plus an Arduino UNO R4 WiFi and two blue Grove buzzers. Video stays on the phone. A left box is not a command to turn left. Quiet buzzers are not an all-clear. We have not run this page on a phone or heard the buzzers.

1. What this phone can see

Checking this page.

Rotation: not requested. Rotation is not position and not a distance.

2. Camera only

Starts the rear camera. It does not load the model and does not talk to the board.

Camera is off.

3. Model only

Loads a COCO-SSD model in this browser and draws boxes. Boxes are 2D image positions. They are not meters. This does not sound a buzzer until section 5 is on.

Model is not loaded.

No detection yet. No detection is not an all-clear.

4. Bluetooth only

Connects to the board named CaneDemo. The switches below sound one buzzer at a time. They are not the camera and they are not turn commands.

Bluetooth is not connected.

No board status yet.

Use manual bench commands Manual left buzzer (D2) Manual right buzzer (D4)

D5 is a link light on the board, not a third buzzer. A slow blip means packets are arriving. A fast pattern means the link timed out. Quiet buzzers are not an all-clear.

5. Camera, model, and Bluetooth together

Looks-close box size

Default is 20% of the picture width or height. This is not meters.

Send an experimental center-zone warning

Combined warning is off.

The same classes, scores, and center half still decide what can count. A counted box also has to look large: its width or height must be at least the percentage above. A gray dashed box says "too small" and does not beep. A big distant object can still pass. A small nearby object can still fail. This is not a measured distance. Image left still sounds D2 and image right still sounds D4. A box center exactly on the middle line sounds both. Boxes outside the center half stay ignored.

What you do, in order

Flash prototype/firmware/uno_r4_wifi/uno_r4_wifi.ino to an Arduino UNO R4 WiFi. In Arduino IDE pick that board, install ArduinoBLE 2.1.0, and use the UNO R4 board package 1.6.0. The sketch opens serial at 115200 and prints Cane demo controller and Advertising CaneDemo as a BLE peripheral.
Plug one Grove cable from the left blue buzzer into the D2 socket, and one from the right blue buzzer into the D4 socket. Leave D3 and D5 without buzzers. Do not power a bare motor from a header pin.
Install Bluefy yourself from the App Store. Open this HTTPS page in Bluefy on the iPhone 16. A laptop is not the runtime.
Read section 1. Then try camera alone, model alone, and Bluetooth alone. Then turn on section 5.
With a sighted spotter, check the physical outputs listed at the bottom. Do not cover anyone's eyes. The cane you already use stays the cane.

What a spotter can check

Before the phone connects, D5 uses the fast outage pattern and D2, D3, and D4 stay off. Serial prints link=outage.
After Connect, D5 changes to a short blip about every 2 seconds. Serial prints accepted source= and an increasing seq.
Manual left sounds only D2. Manual right sounds only D4. Both switches together sound the steady object pattern on both buzzers.
Stop the camera while connected. Both buzzers change to a double blip once a second, and D3 stays on. That double blip means not ready. It does not mean objects are on both sides.
Switch the phone away from Bluefy, or turn Bluetooth off. Within about a second D2, D3, and D4 go off and D5 returns to the fast pattern.
Come back and tap Connect if it does not reconnect. Section 5 stays off until you turn it on again.