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Merged
sonnyp merged 2 commits into from
May 12, 2025
Merged

backend: Read hardware config once #600

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backend: Read hardware config once
sonnyp May 7, 2025
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sonnyp May 7, 2025
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20 changes: 15 additions & 5 deletions device-backend/control/planktoscopehat/main.py
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Original file line number Diff line number Diff line change
Expand Up @@ -3,6 +3,7 @@
import time
import signal
import os
import json

from loguru import logger

Expand Down Expand Up @@ -53,7 +54,7 @@ def handler_stop_signals(signum, frame):
if __name__ == "__main__":
logger.info("Welcome!")
logger.info(
"Initialising signals handling and sanitizing the directories (step 1/5)"
"Initialising configuration, signals handling and sanitizing the directories (step 1/5)"
)
signal.signal(signal.SIGINT, handler_stop_signals)
signal.signal(signal.SIGTERM, handler_stop_signals)
Expand Down Expand Up @@ -84,25 +85,34 @@ def handler_stop_signals(signum, frame):
f"This PlanktoScope's machine name is {planktoscope.identity.load_machine_name()}"
)

try:
with open("/home/pi/PlanktoScope/hardware.json", "r") as config_file:
configuration = json.load(config_file)
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@ethanjli ethanjli May 8, 2025 •
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As mentioned in #578 (which this PR is linked to as a closing PR), this would be a great opportunity to log something (using the loguru-based logger) when json.load fails to parse the open file and throws some kind of exception (which is not a FileNotFoundError and thus is not caught by any exception handler which would write the exception traceback to logger, as far as I can tell).

Maybe one option would be to move everything currently under if __name__ == '__main__': into a new main function, and then to just have a top-level catch-all exception handler around main(), e.g. like the following code which might not be syntactically correct:

if __name__ == '__main__':
  try:
    main()
  except e:
    logger.exception('uncaught exception:', e)
    raise e

Adding this kind of top-level exception handler into this PR might be sufficient to mark #553 as resolved once this PR is merged.

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@ethanjli ethanjli May 8, 2025

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On second thought, now that I've started #602 I think I'd like to make the change described above in that PR instead of this PR, so that the top-level exception handler will be truly top-level (i.e. in the if __name__ == '__main__' block of ~/PlanktoScope/device-backend/control/main.py); in that case, #602 will resolve #553. Once you merge this PR, then in #602 I can move code in the adafruithat/main.py and planktoscopehat/main.py scripts into def main() function blocks so that those main functions can be invoked via module imports from ~/PlanktoScope/device-backend/control/main.py.

except FileNotFoundError:
logger.info(
"The hardware configuration file doesn't exists, using defaults"
)
configuration = {}

# Prepare the event for a graceful shutdown
shutdown_event = multiprocessing.Event()
shutdown_event.clear()

# Starts the pump process
logger.info("Starting the pump control process (step 2/5)")
pump_thread = planktoscope.pump.PumpProcess(shutdown_event)
pump_thread = planktoscope.pump.PumpProcess(shutdown_event, configuration)
pump_thread.start()

# Starts the focus process
logger.info("Starting the focus control process (step 3/5)")
focus_thread = planktoscope.focus.FocusProcess(shutdown_event)
focus_thread = planktoscope.focus.FocusProcess(shutdown_event, configuration)
focus_thread.start()

# TODO try to isolate the imager thread (or another thread)
# Starts the imager control process
logger.info("Starting the imager control process (step 4/5)")
try:
imager_thread = imager.Worker(shutdown_event)
imager_thread = imager.Worker(shutdown_event, configuration)
except Exception as e:
logger.error(f"The imager control process could not be started: {e}")
imager_thread = None
Expand All @@ -112,7 +122,7 @@ def handler_stop_signals(signum, frame):
# Starts the light process
logger.info("Starting the light control process (step 5/5)")
try:
light_thread = planktoscope.light.LightProcess(shutdown_event)
light_thread = planktoscope.light.LightProcess(shutdown_event, configuration)
except Exception:
logger.error("The light control process could not be started")
light_thread = None
Expand Down
21 changes: 6 additions & 15 deletions device-backend/control/planktoscopehat/planktoscope/camera/mqtt.py
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Original file line number Diff line number Diff line change
@@ -1,7 +1,6 @@
"""mqtt provides an MJPEG+MQTT API for camera supervision and interaction."""

import json
import os
import threading
import time
import typing
Expand All @@ -17,7 +16,11 @@
class Worker(threading.Thread):
"""Runs a camera with live MJPEG preview and an MQTT API for adjusting camera settings."""

def __init__(self, mjpeg_server_address: tuple[str, int] = ("", 8000)) -> None:
def __init__(
self,
configuration: dict[str, typing.Any],
mjpeg_server_address: tuple[str, int] = ("", 8000),
) -> None:
"""Initialize the backend.

Args:
Expand Down Expand Up @@ -50,19 +53,7 @@ def __init__(self, mjpeg_server_address: tuple[str, int] = ("", 8000)) -> None:
sharpness=0, # disable the default "normal" sharpening level
jpeg_quality=95, # maximize image quality
)
if os.path.exists("/home/pi/PlanktoScope/hardware.json"):
# load hardware.json
with open("/home/pi/PlanktoScope/hardware.json", "r", encoding="utf-8") as config_file:
hardware_config = json.load(config_file)
loguru.logger.debug(
f"Loaded hardware configuration file: {hardware_config}",
)
settings = settings.overlay(hardware.config_to_settings_values(hardware_config))
else:
loguru.logger.info(
"The hardware configuration file doesn't exist, using default settings: "
+ f"{settings}"
)
settings = settings.overlay(hardware.config_to_settings_values(configuration))

# I/O
self._preview_stream: hardware.PreviewStream = hardware.PreviewStream()
Expand Down
13 changes: 1 addition & 12 deletions device-backend/control/planktoscopehat/planktoscope/focus.py
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Original file line number Diff line number Diff line change
@@ -1,4 +1,3 @@
import json
import multiprocessing
import os
import time
Expand All @@ -22,23 +21,13 @@ class FocusProcess(multiprocessing.Process):
# focus max speed is in mm/sec and is limited by the maximum number of pulses per second the PlanktoScope can send
focus_max_speed = 5

def __init__(self, event):
def __init__(self, event, configuration):
super(FocusProcess, self).__init__()
logger.info("Initialising the focus process")

self.stop_event = event
self.focus_started = False

if os.path.exists("/home/pi/PlanktoScope/hardware.json"):
# load hardware.json
with open("/home/pi/PlanktoScope/hardware.json", "r") as config_file:
# TODO #100 insert guard for config_file empty
configuration = json.load(config_file)
logger.debug(f"Hardware configuration loaded is {configuration}")
else:
logger.info("The hardware configuration file doesn't exists, using defaults")
configuration = {}

# parse the config data. If the key is absent, we are using the default value
self.focus_steps_per_mm = configuration.get("focus_steps_per_mm", self.focus_steps_per_mm)
self.focus_max_speed = configuration.get("focus_max_speed", self.focus_max_speed)
Expand Down
6 changes: 4 additions & 2 deletions device-backend/control/planktoscopehat/planktoscope/imager/mqtt.py
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Original file line number Diff line number Diff line change
Expand Up @@ -29,7 +29,7 @@ class Worker(multiprocessing.Process):
# TODO(ethanjli): instead of passing in a stop_event, just expose a `close()` method! This
# way, we don't give any process the ability to stop all other processes watching the same
# stop_event!
def __init__(self, stop_event: threading.Event) -> None:
def __init__(self, stop_event: threading.Event, configuration) -> None:
"""Initialize the worker's internal state, but don't start anything yet.

Args:
Expand All @@ -52,6 +52,8 @@ def __init__(self, stop_event: threading.Event) -> None:
# constructor.
self._camera: typing.Optional[camera.Worker] = None

self.configuration = configuration

loguru.logger.success("planktoscope.imager is initialized and ready to go!")

@loguru.logger.catch
Expand All @@ -74,7 +76,7 @@ def run(self) -> None:
loguru.logger.success("Pump RPC client is ready!")

loguru.logger.info("Starting the camera...")
self._camera = camera.Worker()
self._camera = camera.Worker(self.configuration)
self._camera.start()
if self._camera.camera is None:
loguru.logger.error(
Expand Down
18 changes: 4 additions & 14 deletions device-backend/control/planktoscopehat/planktoscope/light.py
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Original file line number Diff line number Diff line change
Expand Up @@ -3,7 +3,6 @@
################################################################################
# Logger library compatible with multiprocessing
from loguru import logger
import json

from gpiozero import DigitalOutputDevice

Expand Down Expand Up @@ -40,22 +39,13 @@ class Register(enum.IntEnum):
# This constant defines the current (mA) sent to the LED, 10 allows the use of the full ISO scale and results in a voltage of 2.77v
DEFAULT_CURRENT = 10

def __init__(self):
try:
with open("/home/pi/PlanktoScope/hardware.json", "r") as config_file:
configuration = json.load(config_file)
except FileNotFoundError:
logger.info(
"The hardware configuration file doesn't exists, using defaults"
)
configuration = {}

def __init__(self, configuration):
hat_type = configuration.get("hat_type") or ""
hat_version = float(configuration.get("hat_version") or 0)

# The led is controlled by LM36011
# but on version 1.2 of the PlanktoScope HAT (PlanktoScope v2.6)
# the circuit is connected to that pin so it needs to be high
# the circuit is connected to the pin 18 so it needs to be high
# pin is assigned to self to prevent gpiozero from immediately releasing it
if hat_type != "planktoscope" or hat_version < 3.1:
self.__pin = DigitalOutputDevice(pin=18, initial_value=True)
Expand Down Expand Up @@ -176,7 +166,7 @@ def _read_byte(self, address):
class LightProcess(multiprocessing.Process):
"""This class contains the main definitions for the light of the PlanktoScope"""

def __init__(self, event):
def __init__(self, event, configuration):
"""Initialize the Light class

Args:
Expand All @@ -189,7 +179,7 @@ def __init__(self, event):
self.stop_event = event
self.light_client = None
try:
self.led = i2c_led()
self.led = i2c_led(configuration)
self.led.set_torch_current(self.led.DEFAULT_CURRENT)
self.led.activate_torch_ramp()
self.led.activate_torch()
Expand Down
13 changes: 1 addition & 12 deletions device-backend/control/planktoscopehat/planktoscope/pump.py
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Original file line number Diff line number Diff line change
@@ -1,4 +1,3 @@
import json
import multiprocessing
import os
import time
Expand All @@ -24,23 +23,13 @@ class PumpProcess(multiprocessing.Process):
# pump max speed is in ml/min
pump_max_speed = 50

def __init__(self, event):
def __init__(self, event, configuration):
super(PumpProcess, self).__init__()
logger.info("Initialising the pump process")

self.stop_event = event
self.pump_started = False

if os.path.exists("/home/pi/PlanktoScope/hardware.json"):
# load hardware.json
with open("/home/pi/PlanktoScope/hardware.json", "r") as config_file:
# TODO #100 insert guard for config_file empty
configuration = json.load(config_file)
logger.debug(f"Hardware configuration loaded is {configuration}")
else:
logger.info("The hardware configuration file doesn't exists, using defaults")
configuration = {}

# parse the config data. If the key is absent, we are using the default value
self.pump_steps_per_ml = configuration.get("pump_steps_per_ml", self.pump_steps_per_ml)
self.pump_max_speed = configuration.get("pump_max_speed", self.pump_max_speed)
Expand Down