Remote Control - As The Remote Device

# This work is licensed under the MIT license.
# Copyright (c) 2013-2023 OpenMV LLC. All rights reserved.
# https://github.com/openmv/openmv/blob/master/LICENSE
#
# Remote Control - As The Remote Device
#
# This script configures your OpenMV Cam as a co-processor that can be remotely controlled by
# another microcontroller or computer such as an Arduino, ESP8266/ESP32, RaspberryPi, and
# even another OpenMV Cam.
#
# This script is designed to pair with "popular_features_as_the_controller_device.py".

import image
import math
import rpc
import csi
import struct

csi0 = csi.CSI()
csi0.reset()
csi0.pixformat(csi.RGB565)
csi0.framesize(csi.QVGA)
csi0.snapshot(time=2000)

# The RPC library above is installed on your OpenMV Cam and provides multiple classes for
# allowing your OpenMV Cam to be controlled over CAN, I2C, SPI, or UART.

################################################################
# Choose the interface you wish to control your OpenMV Cam over.
################################################################

# Uncomment the below line to setup your OpenMV Cam for control over CAN.
#
# * message_id - CAN message to use for data transport on the can bus (11-bit).
# * bit_rate - CAN bit rate.
# * sample_point - Tseg1/Tseg2 ratio. Typically 75%. (50.0, 62.5, 75, 87.5, etc.)
#
# NOTE: Master and slave message ids and can bit rates must match. Connect master can high to slave
#       can high and master can low to slave can lo. The can bus must be terminated with 120 ohms.
#
# interface = rpc.rpc_can_slave(message_id=0x7FF, bit_rate=250000, sample_point=75)

# Uncomment the below line to setup your OpenMV Cam for control over I2C.
#
# * slave_addr - I2C address.
#
# NOTE: Master and slave addresses must match. Connect master scl to slave scl and master sda
#       to slave sda. You must use external pull ups. Finally, both devices must share a ground.
#
# interface = rpc.rpc_i2c_slave(slave_addr=0x12)

# Uncomment the below line to setup your OpenMV Cam for control over SPI.
#
# * cs_pin - Slave Select Pin.
# * clk_polarity - Idle clock level (0 or 1).
# * clk_phase - Sample data on the first (0) or second edge (1) of the clock.
#
# NOTE: Master and slave settings much match. Connect CS, SCLK, MOSI, MISO to CS, SCLK, MOSI, MISO.
#       Finally, both devices must share a common ground.
#
# interface = rpc.rpc_spi_slave(cs_pin="P3", clk_polarity=1, clk_phase=0)

# Uncomment the below line to setup your OpenMV Cam for control over UART.
#
# * baudrate - Serial Baudrate.
#
# NOTE: Master and slave baud rates must match. Connect master tx to slave rx and master rx to
#       slave tx. Finally, both devices must share a common ground.
#
interface = rpc.rpc_uart_slave(baudrate=115200)

################################################################
# Call Backs
################################################################

# Helper methods used by the call backs below.


def draw_detections(img, dects):
    for d in dects:
        c = d.corners
        c_len = len(c)
        for i in range(c_len):
            img.draw_line(c[(i + 0) % c_len] + c[(i + 1) % c_len], color=(0, 255, 0))
        img.draw_rectangle(d.rect, color=(255, 0, 0))


# Remote control works via call back methods that the controller
# device calls via the rpc module on this device. Call backs
# are functions which take a bytes() object as their argument
# and return a bytes() object as their result. The rpc module
# takes care of moving the bytes() objects across the link.
# bytes() may be the micropython int max in size.


# When called returns x, y, w, and h of the largest face within view.
#
# data is unused
def face_detection(data):
    csi0.pixformat(csi.GRAYSCALE)
    csi0.framesize(csi.QVGA)
    img = csi0.snapshot()
    faces = (
        img.gamma_corr(contrast=1.5)
        .find_features(image.HaarCascade("/rom/haarcascade_frontalface.cascade"))
    )
    if not faces:
        return bytes()  # No detections.
    for f in faces:
        img.draw_rectangle(f, color=(255, 255, 255))
    out_face = max(faces, key=lambda f: f[2] * f[3])
    return struct.pack("<HHHH", out_face[0], out_face[1], out_face[2], out_face[3])


# When called returns the payload string for the largest qrcode
# within the OpenMV Cam's field-of-view.
#
# data is unused
def qrcode_detection(data):
    csi0.pixformat(csi.RGB565)
    csi0.framesize(csi.VGA)
    csi0.window((320, 240))
    img = csi0.snapshot()
    codes = img.find_qrcodes()
    if not codes:
        return bytes()  # No detections.
    draw_detections(img, codes)
    return max(codes, key=lambda c: c.w * c.h).payload.encode()


# When called returns a json list of json qrcode objects for all qrcodes in view.
#
# data is unused
def all_qrcode_detection(data):
    csi0.pixformat(csi.RGB565)
    csi0.framesize(csi.VGA)
    csi0.window((320, 240))
    img = csi0.snapshot()
    codes = img.find_qrcodes()
    if not codes:
        return bytes()  # No detections.
    draw_detections(img, codes)
    return str(codes).encode()


# When called returns the x/y centroid, id number, and rotation of the largest
# AprilTag within the OpenMV Cam's field-of-view.
#
# data is unused
def apriltag_detection(data):
    csi0.pixformat(csi.RGB565)
    csi0.framesize(csi.QQVGA)
    img = csi0.snapshot()
    tags = img.find_apriltags()
    if not tags:
        return bytes()  # No detections.
    draw_detections(img, tags)
    output_tag = max(tags, key=lambda t: t.w * t.h)
    return struct.pack(
        "<HHHH",
        output_tag.cx,
        output_tag.cy,
        output_tag.id,
        int(math.degrees(output_tag.rotation)),
    )


# When called returns a json list of json apriltag objects for all apriltags in view.
#
# data is unused
def all_apriltag_detection(data):
    csi0.pixformat(csi.RGB565)
    csi0.framesize(csi.QQVGA)
    img = csi0.snapshot()
    tags = img.find_apriltags()
    if not tags:
        return bytes()  # No detections.
    draw_detections(img, tags)
    return str(tags).encode()


# When called returns the payload string for the largest datamatrix
# within the OpenMV Cam's field-of-view.
#
# data is unused
def datamatrix_detection(data):
    csi0.pixformat(csi.RGB565)
    csi0.framesize(csi.VGA)
    csi0.window((320, 240))
    img = csi0.snapshot()
    codes = img.find_datamatrices()
    if not codes:
        return bytes()  # No detections.
    draw_detections(img, codes)
    return max(codes, key=lambda c: c.w * c.h).payload.encode()


# When called returns a json list of json datamatrix objects for all datamatrices in view.
#
# data is unused
def all_datamatrix_detection(data):
    csi0.pixformat(csi.RGB565)
    csi0.framesize(csi.VGA)
    csi0.window((320, 240))
    img = csi0.snapshot()
    codes = img.find_datamatrices()
    if not codes:
        return bytes()  # No detections.
    draw_detections(img, codes)
    return str(codes).encode()


# When called returns the payload string for the largest barcode
# within the OpenMV Cam's field-of-view.
#
# data is unused
def barcode_detection(data):
    csi0.pixformat(csi.GRAYSCALE)
    csi0.framesize(csi.VGA)
    csi0.window((csi0.width(), csi0.height() // 8))
    img = csi0.snapshot()
    codes = img.find_barcodes()
    if not codes:
        return bytes()  # No detections.
    return max(codes, key=lambda c: c.w * c.h).payload.encode()


# When called returns a json list of json barcode objects for all barcodes in view.
#
# data is unused
def all_barcode_detection(data):
    csi0.pixformat(csi.GRAYSCALE)
    csi0.framesize(csi.VGA)
    csi0.window((csi0.width(), csi0.height() // 8))
    img = csi0.snapshot()
    codes = img.find_barcodes()
    if not codes:
        return bytes()  # No detections.
    return str(codes).encode()


# When called returns the x/y centroid of the largest blob
# within the OpenMV Cam's field-of-view.
#
# data is the 6-byte color tracking threshold tuple of L_MIN, L_MAX, A_MIN, A_MAX, B_MIN, B_MAX.
def color_detection(data):
    csi0.pixformat(csi.RGB565)
    csi0.framesize(csi.QVGA)
    thresholds = struct.unpack("<bbbbbb", data)
    img = csi0.snapshot()
    blobs = img.find_blobs(
        [thresholds], pixels_threshold=500, area_threshold=500, merge=True, margin=20
    )
    if not blobs:
        return bytes()  # No detections.
    for b in blobs:
        img.draw_detection(b, color1=(255, 0, 0), color2=(0, 255, 0))
    out_blob = max(blobs, key=lambda b: b.density)
    return struct.pack("<HH", out_blob.cx, out_blob.cy)


# When called returns a jpeg compressed image from the OpenMV
# Cam in one RPC call.
#
# data is unused
def jpeg_snapshot(data):
    csi0.pixformat(csi.RGB565)
    csi0.framesize(csi.QVGA)
    img = csi0.snapshot()
    img.to_jpeg(quality=90)
    return img.bytearray()


# Register call backs.

interface.register_callback(face_detection)
interface.register_callback(qrcode_detection)
interface.register_callback(all_qrcode_detection)
interface.register_callback(apriltag_detection)
interface.register_callback(all_apriltag_detection)
interface.register_callback(datamatrix_detection)
interface.register_callback(all_datamatrix_detection)
interface.register_callback(barcode_detection)
interface.register_callback(all_barcode_detection)
interface.register_callback(color_detection)
interface.register_callback(jpeg_snapshot)

# Once all call backs have been registered we can start
# processing remote events. interface.loop() does not return.

interface.loop()