Flood Tracker | How To Build a Electron Distance Sensor

Miami floods "badly" as of recently due to many factors. We at Code for Miami see this as a problem that needs to be addressed. For that reason, we are showing others DIY ways to build their own sensors to track flooding.

In this experiment, you are going to build a sensor that is able to measure distances from 10cm up to 200cm. The data will be transmitted via cell to The Particle cloud service.

Required Parts

To build this sensor, you need the following hardware:

• 1x perfboard
• 1x Particle Electron kit
• 1x RCWL-1601 ultrasonic range sensor
• 1x 470 Ohm resistor
• 1x 1k Ohm resistor
• 4x wires with female ends for the sensor (the other ends will be clipped and soldered)
• miscellaneous wires
• 1x 3.7V lithium-ion battery
• 1x Adafruit MCP73871 USB/Solar LiPoly/Li-Ion Charger TODO: FIGURE OUT IF THE NEW ONE WORKS
• 1x solar panel
• 1x BAPI-Box weatherproof junction box

Useful Parts

• 1x 60cm long 3" schedule 40 PVC pipe for the main housing
• 1x end cap
• 1x support bracket for the RCWL-1601 in the PVC pipe
• 2x hook & loop fasteners
• 1x 2" long 1" PVC pipe to connect the junction box to the main housing
• silicone sealant
• glue

Prepare your laptop

https://docs.particle.io/guide/tools-and-features/cli/photon/

Wire up the circuit on breadboard

TODO: FIGURE OUT IF THE VOLTAGE DIVIDER IS NECESSARY

Place components as shown in the schema.

The HC-SR04 sensor is a 5V device, while the Electron operates at 3.3V. Therefore, we provide power to the sensor from the Vin pin (= 5V from USB).

The 2 resistors function as a voltage divider to convert the 5V coming from the sensor to a safe 3.3V level.

R1: 470 Ohm (yellow purple black black [brown]) R2: 1k Ohm (brown black black brown [brown])

Connect Particle to the cloud

Identify device

Connect the device to your computer using USB and place the device in [listening mode](blinking dark blue) by holding down the S MODE button until the main status LED blinks dark blue, about 3 seconds

First, you want to know the Device ID of the Photon you just connected:

$ particle identify

Your device id is 2300211353337353037
Your IMEI is 35316207243
Your ICCID is 8936500002860393
Your system firmware version is 0.7.0

If firmware version not 0.7.0 or higher, see Mario or Christina.

Copy this device id to your TextPad. You will need it in a few moments.

The Photon status LED should be BREATHING CYAN when it's happily connected to the internet.

Add the device to your account (See Mario or Cristina to be added to the Code for Miami account)

Write sketch for the Photon

Open the online build environment of Particle.io on build.particle.io.

At the left-hand side, you can see the vertical menu on the left hand side which you will use during the process. Hover your mouse over each item to get familiar with the different options:

FLASH - VERIFY - SAVE - CODE - LIBRARIES - DOCS - DEVICES - SETTINGS

Let's get started!

• First, we want to select the Photon we connected to our account in the previous step. From the menu, press DEVICES
• Check if your device is listed and select it by clicking the yellow star in front of the device name.
• From the menu, press "\< \>" Code to open the code editor
• Press CREATE NEW APP and enter a Title (e.g. MyFloodMeasuring )
• Again, at the left-hand side, press Libraries (first item below "\< \>")
• In the Community Libraries search box, type: HC_SR04
• Press on the search result HC_SR04
• Press INCLUDE IN APP, select the app you just created (e.g. MyFloodMeasuring) and press ADD TO THIS APP

Paste the code from GitHub url, https://github.com/Code-for-Miami/iot-flood-tracker/blob/master/GiveMeData.ino replacing it's current content

• From the menu, press VERIFY. This should result in the message Code verified! Great work.
• Now you are ready to press FLASH If everything goes well, you will see the following message:

Flash successful! Please wait a moment while your device is updated...

• The device should return to BREATHING CYAN status color

Monitor the published sensor values

Debug readings from local serial port (Photon need to be connected to USB)

$ particle serial monitor
Opening serial monitor for com port: "/dev/tty.usbmodem1411"
Serial monitor opened successfully:
Report: 13.55 cm
Report: 55.19 cm
Report: 55.17 cm
Report: 59.33 cm
Report: -1.00 cm
Report: 55.88 cm
Report: 57.36 cm
Report: 30.78 cm
Report: 110.74 cm
Report: -1.00 cm
Report: 229.14 cm
Report: 231.03 cm

Go Hack add features and build the hardware