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- """glitter positioning system"""
-
- import time
- import gc
- import math
- import adafruit_lsm9ds1
- import adafruit_gps
- import adafruit_rfm9x
- import board
- import busio
- import digitalio
- import neopixel
- import rtc
- from glitterpos_util import timestamp, compass_bearing, bearing_to_pixel, map_range
-
- # glitterpos_cfg.py should be unique to each box, and formatted as follows:
- #
- # MY_ID = 0 # must be a unique integer
- # MAG_MIN = (-0.25046, -0.23506, -0.322)
- # MAG_MAX = (0.68278, 0.70882, 0.59654)
- # DECLINATION_RAD = 235.27 / 1000.0 # Black Rock City in radians
- #
- # From the CircuitPython REPL, use `import calibrate` to find values for
- # MAG_MIN and MAG_MAX.
- from glitterpos_cfg import MY_ID, MAG_MIN, MAG_MAX, DECLINATION_RAD
-
- # Colors for status lights, NeoPixel ring, etc.:
- RED = (255, 0, 0)
- YELLOW = (255, 150, 0)
- GREEN = (0, 255, 0)
- CYAN = (0, 255, 255)
- BLUE = (0, 0, 255)
- PURPLE = (180, 0, 255)
-
- # BOULDER_ID = 23
-
- # Color presets for each glitterpos_id:
- COLOR_LOOKUP = {
- 0: GREEN,
- 1: BLUE,
- 2: PURPLE,
- 3: YELLOW,
- 4: CYAN,
- 5: (100, 0, 255),
- 6: (0, 100, 200),
- 7: (100, 50, 100),
- # BOULDER_ID: RED
- }
-
- # You can add fixed points here:
- DEFAULT_BOX_COORDS = {
- # BOULDER_ID: (40.018258, -105.278457)
- }
-
- RADIO_FREQ_MHZ = 915.0
- CS = digitalio.DigitalInOut(board.D10)
- RESET = digitalio.DigitalInOut(board.D11)
-
- class GlitterPOS:
- """glitter positioning system"""
-
- def __init__(self):
- """configure sensors, radio, blinkenlights"""
-
- # Our id and the dict for storing coords of other glitterpos_boxes:
- self.glitterpos_id = MY_ID
- self.glitterpos_boxes = DEFAULT_BOX_COORDS
-
- # Set the RTC to an obviously bogus time for debugging purposes:
- # time_struct takes: (tm_year, tm_mon, tm_mday, tm_hour, tm_min, tm_sec, tm_wday, tm_yday, tm_isdst)
- rtc.RTC().datetime = time.struct_time((2000, 1, 1, 0, 0, 0, 0, 0, 0))
- print("startup time: " + timestamp())
- self.time_set = False
- self.last_send = time.monotonic()
-
- # A tuple for our lat/long:
- self.coords = (0, 0)
- self.heading = 0.0
-
- # Status light on the board, we'll use to indicate GPS fix, etc.:
- self.statuslight = neopixel.NeoPixel(board.NEOPIXEL, 1, brightness=0.005, auto_write=True)
- self.statuslight.fill(RED)
-
- # Neopixel ring:
- self.pixels = neopixel.NeoPixel(board.A1, 16, brightness=0.01, auto_write=False)
- self.startup_animation()
- time.sleep(2)
-
- self.init_radio()
- self.init_gps()
- self.init_compass()
-
- self.statuslight.fill(YELLOW)
-
- def startup_animation(self):
- """Initialize NeoPixel test pattern."""
- self.pixels[bearing_to_pixel(0)] = PURPLE
- self.pixels.show()
- time.sleep(.5)
- self.pixels[bearing_to_pixel(90)] = GREEN
- self.pixels.show()
- time.sleep(.5)
- self.pixels[bearing_to_pixel(180)] = YELLOW
- self.pixels.show()
- time.sleep(.5)
- self.pixels[bearing_to_pixel(270)] = BLUE
- self.pixels.show()
-
- def init_radio(self):
- """Set up RFM95."""
- spi = busio.SPI(board.SCK, MOSI=board.MOSI, MISO=board.MISO)
- self.rfm9x = adafruit_rfm9x.RFM9x(spi, CS, RESET, RADIO_FREQ_MHZ)
- self.rfm9x.tx_power = 18 # Default is 13 dB; the RFM95 goes up to 23 dB
- self.radio_tx('d', 'hello world')
- time.sleep(1)
-
- def init_gps(self):
- """Set up GPS module."""
- uart = busio.UART(board.TX, board.RX, baudrate=9600, timeout=3000)
- gps = adafruit_gps.GPS(uart)
- time.sleep(1)
-
- # https://cdn-shop.adafruit.com/datasheets/PMTK_A11.pdf
- # Turn on the basic GGA and RMC info (what you typically want), then
- # set update to once a second:
- gps.send_command('PMTK314,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0')
- gps.send_command('PMTK220,1000')
-
- self.gps = gps
-
- def init_compass(self):
- """Set up LSM9DS1."""
- i2c = busio.I2C(board.SCL, board.SDA)
- self.compass = adafruit_lsm9ds1.LSM9DS1_I2C(i2c)
- time.sleep(1)
-
- def advance_frame(self):
- """
- Check the radio for new packets, poll GPS and compass data, send a
- radio packet if coordinates have changed (or if it's been a while), and
- update NeoPixel display. Called in an infinite loop by code.py.
-
- To inspect the state of the system, initialize a new GlitterPOS object
- from the CircuitPython REPL, and call gp.advance_frame() manually. You
- can then access the instance variables defined in __init__() and
- init_()* methods.
- """
-
- current = time.monotonic()
- self.radio_rx(timeout=0.5)
- new_gps_data = self.gps.update()
- self.update_heading()
- self.display_pixels()
-
- if not self.gps.has_fix:
- # Try again if we don't have a fix yet.
- self.statuslight.fill(RED)
- return
-
- # We want to send coordinates out either on new GPS data or roughly
- # every 15 seconds:
- if (not new_gps_data) and (current - self.last_send < 15):
- return
-
- # Set the RTC to GPS time (UTC):
- if new_gps_data and not self.time_set:
- rtc.RTC().datetime = self.gps.timestamp_utc
- self.time_set = True
-
- gps_coords = (self.gps.latitude, self.gps.longitude)
- if gps_coords == self.coords:
- return
-
- self.coords = (self.gps.latitude, self.gps.longitude)
-
- self.statuslight.fill(BLUE)
- print(':: ' + str(current)) # Print a separator line.
- print(timestamp())
- send_packet = '{}:{}:{}:{}'.format(
- self.gps.latitude,
- self.gps.longitude,
- self.gps.speed_knots,
- self.heading
- )
-
- print(' quality: {}'.format(self.gps.fix_quality))
- print(' ' + str(gc.mem_free()) + " bytes free")
-
- # Send a location packet:
- self.radio_tx('l', send_packet)
-
- def update_heading(self):
- mag_x, mag_y, mag_z = self.compass.magnetometer
- # print('Magnetometer: ({0:10.3f}, {1:10.3f}, {2:10.3f})'.format(mag_x, mag_y, mag_z))
- mag_x = map_range(mag_x, MAG_MIN[0], MAG_MAX[0], -1, 1)
- mag_y = map_range(mag_y, MAG_MIN[1], MAG_MAX[1], -1, 1)
- mag_z = map_range(mag_z, MAG_MIN[2], MAG_MAX[2], -1, 1)
-
- heading_mag = (math.atan2(mag_y, mag_x) * 180) / math.pi
- if heading_mag < 0:
- heading_mag = 360 + heading_mag
-
- # Account for declination (given in radians above):
- heading = heading_mag + (DECLINATION_RAD * 180 / math.pi)
- if heading > 360:
- heading = heading - 360
-
- print('heading: {}'.format(heading))
- self.heading = heading
-
- def radio_tx(self, msg_type, msg):
- """send a packet over radio with id prefix"""
- packet = 'e:' + msg_type + ':' + str(self.glitterpos_id) + ':' + msg
- print(' sending: ' + packet)
-
- # Blocking, max of 252 bytes:
- self.rfm9x.send(packet)
- self.last_send = time.monotonic()
-
- def radio_rx(self, timeout=0.5):
- """check radio for new packets, handle incoming data"""
-
- packet = self.rfm9x.receive(timeout)
-
- # If no packet was received during the timeout then None is returned:
- if packet is None:
- return
-
- packet = bytes(packet)
- print(timestamp())
- print(' received signal strength: {0} dB'.format(self.rfm9x.rssi))
- print(' received (raw bytes): {0}'.format(packet))
- pieces = packet.split(b':')
-
- if pieces[0] != b'e' or len(pieces) < 5:
- print(' bogus packet, bailing out')
- return
-
- msg_type = pieces[1].format()
- sender_id = int(pieces[2].format())
-
- # A location message:
- if msg_type == 'l':
- sender_lat = float(pieces[3].format())
- sender_lon = float(pieces[4].format())
- self.glitterpos_boxes[sender_id] = (sender_lat, sender_lon)
-
- # packet_text = str(packet, 'ascii')
- # print('Received (ASCII): {0}'.format(packet_text))
-
- def display_pixels(self):
- """Display current state on the NeoPixel ring."""
- self.pixels.fill((0, 0, 0))
-
- # We can't meaningfully point at other locations if we don't know our
- # own position:
- if not self.gps.has_fix:
- return
-
- for box in self.glitterpos_boxes:
- bearing_to_box = compass_bearing(self.coords, self.glitterpos_boxes[box])
-
- # Treat current compass heading as our origin point for display purposes:
- display_bearing = bearing_to_box - self.heading
- if display_bearing < 0:
- display_bearing = display_bearing + 360
-
- pixel = bearing_to_pixel(display_bearing)
- # print('display pixel: {}'.format(pixel))
-
- color = (15, 15, 15)
- if box in COLOR_LOOKUP:
- color = COLOR_LOOKUP[box]
- self.pixels[pixel] = color
-
- self.pixels.show()
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