Second Sketch: logging_to_MMW.ino

Overview

Teaching: 10 min
Exercises: 30 min

Questions

• Where in my sketch do I put UUIDs from Monitor My Watershed?

• How do I find the changes that have been made to a sketch?

Objectives

• Log data to an online repository. Install and use split-diff package.

Episode 13: Your second Modular Sensors sketch

Prerequisites

• Complete all prior episodes.
• For this episode, you’ll need an EnviroDIY Mayfly Data Logger Board, a micro-USB cable rated for data, a CR1220 Lithium Coin Cell 3V Battery, and the following accessories:
  • a DS18B20 Waterproof Digital Temperature sensor and 4.7kΩ resistor,
  • two Grove screw terminals and included Grove cables,
  • a Grove BME280 Temperature, Pressure, and Humidity sensor,
  • an I2C OLED display with Grove connector (optional), and
  • a Grove I²C hub (if you use the OLED display).
• You will need a sensor station set up at MonitorMyWatershed.org as described in Episode 12.
• Additional hardware for this sketch includes a modem (see modem list in Modular Sensors Wiki) and a SIM card (such as from hologram.io).

One of the advantages of working in a code editor is the ability to compare files within the editor. VSCode has this as an embedded extension.

• You will do this by right clicking on each of the files you want to compare and choosing “Select to Compare” for the first file and “Compare with Selected”.

Compare logging_to_MMW.ino and your version of simple_logging.ino in which you added sensors.

• Copy logging_to_MMW.ino from your cloned Modular Sensors to your repository.
• Open both sketches.
• In the Explorer, right click on the new logging_to_MMW.ino and select “Select to Compare” then right click on simple_logging.ino and choose “Compare with Selected”.
• Every line with different content will be highlighted in each file. Depending on how well the diff handles comment out characters, you may be able to see many lines from the sketches align. However, logging_to_MMW.ino has several major differences that we will unpack so you can edit what you need and ignore what you do not need to change. Here are things you do not need to change:
  • small differences in the file header and name
  • a massive section for modem settings (~many lines of code to accommodate nearly any modem you could use with an Arduino),
  • some differences in the sensors,
  • UUIDs in the variable array (until you are setting up a station),
  • a section for “registration and sampling feature information”, and
  • lots of extra code in the setup and loop functions.

Set up logging_to_MMW.ino to run BME280 and/or DS18 sensors.

• In Variable Array, edit your sketch name, logger ID, logging interval and time zone.

  Variable *variableList[] = {
      // your other variables here
      new Modem_RSSI(&modem, "12345678-abcd-1234-efgh-1234567890ab"),
      new Modem_SignalPercent(&modem, "12345678-abcd-1234-efgh-1234567890ab"),
      // your other variables here
  };
  

• In Wifi/Cellular Modem Main Chip Selection, make sure only one modem is uncommented. Recall that commented out lines start with //. If you are using the Mayfly, you will not need to make any additional edits to the modem settings.
• Around line 540, you will find the Network Information and LoggerModem Object section. Change the apn to match your SIM provider: const char *apn = "hologram"; or for WiFi modems, put in the ID and Password.
• Sensors: Beginning around line 566, you should find the sensors. Confirm that they are correctly addressed, as discussed in Episode 10.
• In the Variable Array, copy and paste the tokens and UUIDs from your data.EnviroDIY.org site. - This task is tedious. I recommend pasting the UUIDs from your MonitorMyWatershed.org site in the ReadMe.md file that was included with logging_to_MMW.ino. - Then split your screen between the ReadMe.md file and your sketch. This is different than split diff; it’s simply a split screen without differencing. - With ReadMe.md and logging_to_MMW.ino both open, right click on the tab that is not active and select Split Left (or right or up or down). - This is my preferred method for pasting UUIDs into a sketch.
• In the A Publisher to Monitor My Watershed section, insert your registration token and sampling feature from your MonitorMyWatershed.org site (this should be among the things you pasted into your Readme.md file).

Connect sensors and upload sketch

• Set up the platformio.ini file in the root directory of your repository. Save the ini file.
• Connect the BME280 and or the DS18 to the Mayfly (as we did in Episodes 6 and 10), connect the Mayfly to your computer using the microUSB cable, and turn it on. (Note: Modular Sensors sketches will not run if the SD card is missing.)
• Build/compile and upload your sketch.
• View your sensor using the serial monitor (note: serialBaud = 115200). After the logger is set up, push the round, black button near the SD card on the Mayfly to enter sensor testing mode.
• Your serial monitor will now include information about your modem signal strength. Sometimes the first few logging intervals have low strength, so watch give the modem a warm up period.
• If your modem displays a non-zero signal strength, press the reset button (small, white rectangle near the coin battery and lipo connectors). This will restart the sketch, which allows logging mode to resume. Do not go into sensor testing mode. Wait for logging to begin. If the server response is 201, you have successfully logged to a data repository!

Key Points

• Where to insert UUIDs into Modular Sensors sketches. How to view differences between sketches.