82 lines
2.4 KiB
Markdown
82 lines
2.4 KiB
Markdown
# linefollower_eye
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ESP32-S3 camera board that finds a coloured blob and reports its position over I2C. Meant to sit on a robot as the “eye”, with something like a Pico as the master.
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## What it does
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The ESP runs HSV blob detection on the camera. A MicroPython master can turn the camera on, set colour, and poll for a target. Optionally it can join Wi‑Fi so you can open a browser page to tune the colour live.
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Target position from `read_target()` is relative to the image centre (320x240). Positive x is right, positive y is up. Diameter is the blob size in pixels (2 × detector radius). No target returns `None`.
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## Hardware
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ESP pins for the I2C slave:
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- SDA: GPIO19
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- SCL: GPIO20
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- Address: 0x42
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Example Pico wiring:
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- GP0 (SDA) -> ESP GPIO19
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- GP1 (SCL) -> ESP GPIO20
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- GND shared
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- Use external pull-ups on SDA/SCL (about 2k2–4k7 to 3V3)
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Camera and Wi‑Fi stay off until the master enables them.
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## Firmware
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ESP-IDF project for ESP32-S3. Build and flash as usual:
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```
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idf.py build
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idf.py -p PORT flash monitor
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```
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## MicroPython master
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Files live in `mp_i2c_master/`. Copy `vision.py` (and `main.py` if you want the demo) onto the board.
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```python
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from vision import Vision
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import time
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eye = Vision(sda=0, scl=1)
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eye.start() # start the camera and blob algorithm
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eye.set_hsv(4, 128, 116) # Set target colour (HSV)
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eye.set_rgb(255, 255, 255) # Set RGB LED to max white
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# Optional: browser UI for tuning colour
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#eye.set_wifi("rr workshop", "ourpassword")
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#print(eye.wifi_ip())
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while True:
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target = eye.read_target()
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if target is None:
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print("no target")
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else:
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x, y, diameter = target
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print("target at ({}, {}) diameter={}".format(x, y, diameter))
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time.sleep(0.07)
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```
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Useful calls:
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- `eye.start()` — camera on and local detection
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- `eye.set_hsv(h, s, v)` / `eye.set_tolerance(...)` — colour (or tune in the browser)
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- `eye.set_wifi(ssid, password)` / `eye.wifi_off()` / `eye.wifi_ip()`
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- `eye.read_target()` — `(x, y, diameter)` or `None`
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- `eye.set_rgb(r, g, b)`
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- `eye.set_size_limits(max_diameter=..., max_area=...)` — optional; default is no max size
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## Web UI
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After Wi‑Fi is up, open the ESP’s IP in a browser. You get the live image, colour picker / eyedropper, mask options, and timing. Colour changes there are what the I2C master reads next.
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## Other folders
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- `pc_vision/` — older desktop viewer; the on-device web UI replaces it for tuning
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- `main/` — ESP firmware
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