train demo - firmware for signals

other/train-to-cloud-city/devices/signal/CIRCUITPY/boot.py

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+# Copyright 2024 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import time
+import board
+import neopixel
+import touchio
+
+print("hello from boot.py")
+
+
+
+import usb_cdc
+usb_cdc.enable(data=True, console=False)
+
+import usb_midi
+usb_midi.disable()
+
+import usb_hid
+usb_hid.disable()

other/train-to-cloud-city/devices/signal/CIRCUITPY/code.py

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+# Copyright 2024 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Requirements
+#
+# Download stable version 9 of the CircuitPython runtime:
+# https://circuitpython.org/board/adafruit_qtpy_rp2040/
+# then install via boot mode:
+# https://learn.adafruit.com/welcome-to-circuitpython/installing-circuitpython
+
+print("Hello Trains!")
+
+import board
+import time
+import neopixel
+import usb_cdc
+import asyncio
+
+VERSION = '3'
+
+
+# Colors are (Red, Green, Blue) on a 0-255 scale.
+OFF =    ((0, 0, 0, 0), (0, 0, 0, 0), (0, 0, 0, 0))
+ORANGE = ((25, 15, 0, 0), (250, 150, 0, 0), (250, 150, 0, 0))
+STOP =   ((25, 0, 0, 0), (250, 0, 0, 0), (250, 0, 0, 0))
+CLEAR =  ((0, 25, 0, 0), (0, 250, 0, 0), (0, 250, 0, 0))
+
+HELP = b"""HELP
+Valid commands:
+OFF    Turn off signal light.
+STOP   Set signal light to red.
+CLEAR  Set signal light to green.
+HELP   This text.
+(follow each command with a newline character)"""
+
+BRIGHTNESS = 0.9
+onboard_pixel = neopixel.NeoPixel(board.NEOPIXEL, 1,
+    brightness=BRIGHTNESS)
+
+pixel_pin = board.A0
+num_pixels = 2
+pixels = neopixel.NeoPixel(pixel_pin, num_pixels,
+    brightness=BRIGHTNESS, auto_write=False, pixel_order=(1, 0, 2, 3),)
+
+# This signal's ID. Write some short string to "id.txt"
+try:
+    ID = open("id.txt").read().strip().encode("UTF-8")
+except BaseException:
+    ID = b"UNKNOWN"
+
+board.BUTTON
+from digitalio import DigitalInOut, Direction, Pull
+
+btn = DigitalInOut(board.BUTTON)
+btn.direction = Direction.INPUT
+btn.pull = Pull.UP
+
+
+def init():
+    set_pixels(ORANGE)
+    print(f'my id is: {ID}')
+    usb_cdc.data.write(ID + b':INIT\n')
+    usb_cdc.data.write(ID + b':VERSION ' + VERSION.encode('UTF-8') + '\n')
+
+def set_pixels(color_rgb):
+    onboard_pixel[0] = color_rgb[0][:3]
+    pixels[0] = color_rgb[1]
+    pixels[1] = color_rgb[2]
+    pixels.show()
+
+def serial_response(result):
+    usb_cdc.data.write(ID)
+    usb_cdc.data.write(b':')
+    usb_cdc.data.write(result)
+    usb_cdc.data.write(b'\n')
+
+def parse_and_run_command(input):
+    input = input.strip().upper()
+    if input == b'HELP':
+        set_pixels(ORANGE)
+        return HELP
+    elif input == b'OFF' or input == b'O':
+        set_pixels(OFF)
+        return input
+    elif input == b'STOP' or input == b'S':
+        set_pixels(STOP)
+        return input
+    elif input == b'CLEAR' or input == b'C':
+        set_pixels(CLEAR)
+        return input
+    else:
+        set_pixels(ORANGE)
+        return b'ERROR: Unknown command: ' + input + b' (Enter HELP for command list.)'
+
+async def usb_client():
+    usb_cdc.data.timeout = 0
+    s = asyncio.StreamReader(usb_cdc.data)
+    while True:
+        data = await s.readline()
+        print("input: ", data)
+        try:
+            result = parse_and_run_command(data)
+        except Exception as err:
+            result = 'ERROR: ' + str(type(err)) + str(err)
+            result.encode("UTF-8")
+        serial_response(result)
+
+# Press "BOOT" button to cycle between states.
+async def button():
+    prev_state = btn.value
+    states = [(STOP, b'STOP'), (CLEAR, b'CLEAR'), (OFF, b'OFF'), (ORANGE, b'ERROR')]
+    index = 0
+
+    while True:
+        cur_state = btn.value
+        if cur_state != prev_state:
+            if not cur_state:
+                # print("BUTTON is down")
+                pass
+            else:
+                # print("BUTTON is up")
+                color, result = states[index % 4]
+                set_pixels(color)
+                serial_response(result)
+                index += 1
+        prev_state = cur_state
+        await asyncio.sleep(0.2)
+
+async def counter():
+    i = 0
+    while True:
+        usb_cdc.data.write(ID)
+        usb_cdc.data.write(b':HEARTBEAT\n')
+        await asyncio.sleep(60)
+
+async def main():
+    init()
+    clients = [asyncio.create_task(counter())]
+    clients.append(asyncio.create_task(usb_client()))
+    clients.append(asyncio.create_task(button()))
+    await asyncio.gather(*clients)
+
+asyncio.run(main())

other/train-to-cloud-city/devices/signal/CIRCUITPY/id.txt

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+SIGNAL_A

other/train-to-cloud-city/devices/signal/README.md

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+This is the code which runs on each of the physical signal lights. 
+
+For the demo, they were build out of lego and an Adafruit [QT Py RP2040](https://www.adafruit.com/product/4900) and two [NeoPixel RGBW Mini Button](https://www.adafruit.com/product/4776)s.  
+
+It's possible to test without the extra NeoPixels, the code will also update the NeoPixel on the QT Py board. 
+
+## Installation
+
+Download stable version 9 of the CircuitPython runtime:
+https://circuitpython.org/board/adafruit_qtpy_rp2040/
+
+and the libraries bundle version 9: 
+https://circuitpython.org/libraries
+
+then install via boot mode:
+https://learn.adafruit.com/welcome-to-circuitpython/installing-circuitpython
+
+
+## Installation steps
+
+* Copy the *.uf2 file to the RPI-RP2 volume. It will then reboot into a volume nameed `CIRCUITPY`.
+* Then copy all files in the `CIRCUITPY` directory onto the new USB media volume which should be named `CIRCUITPY`.
+* Then set the ID for this device by editing `id.txt`.
+* Copy needed library modules from the libraries bundle to the `lib` directory on the USB volume: `neopixel_spi.mpy`, `neopixel.mpy`,	`adafruit_ticks.mpy` and the `asyncio` folder.
+* Then eject and reconnect. Should be able to connect with a serial terminal program at 9600 baud. (CoolTerm works well on MacOS)
+
+
+## Protocol
+
+The signal is lit yellow at startup and on errors, green for CLEAR and red for STOP. 
+
+Each signal exposes a USB serial port and accepts commands via a text protocol. 
+
+```plain
+Valid commands:
+OFF    Turn off signal light.
+STOP   Set signal light to red.
+CLEAR  Set signal light to green.
+HELP   This text.
+(follow each command with a newline character)
+```
+And it responds with its' own signal ID and the executed command, or error text:
+```plain
+SIGNAL_A:HEARTBEAT
+SIGNAL_A:CLEAR
+SIGNAL_A:STOP
+SIGNAL_A:CLEAR
+SIGNAL_A:STOP
+SIGNAL_A:ERROR: Unknown command: ABC (Enter HELP for command list.)
+```
+
+It also sends `SIGNAL_A:HEARTBEAT` approximately once a minute.