In the Spring of 2011, CCAT decided to revisit an old priority that had never been fully implemented: The collection of data and various metrics that would help us measure how we're doing on several sustainability or self-sufficiency related fronts:

  • Electricity generation (through our PV system, currently)
  • Electricity consumption
  • Solar hot water temperature
  • Natural gas consumption
  • Wood consumption for our wood-burning stove
  • Greywater quality (TSS, BOD)
  • Tap water quality (health hazards)
  • Water consumption
  • Garden productivity
  • Compost production
  • Indoor air quality

Some of the data will be automatically collected through sensors and devices. Other data will require recurring human readings.

The goal is to make this data easily accessible to everyone -- employees, Co-Directors, students, and the whole world -- for analysis and education.

Real-time digital data collection[edit | edit source]

At the heart of the digital portion of our project is a proprietary data logger, a CR1000 by Campbell Scientific. It measures the input from modular sensors, processes it internally, and saves the results to its internal memory.

When we first started the project, the logger was only used to monitor our solar hot water system. Our engineering technician had to connect to it manually once a month to download its stored data tables.

We wanted to make the logger automatically upload its data in real-time, but we wanted to do it as inexpensively and with as little waste as possible.

Challenges we encountered[edit | edit source]

  1. Campbell Scientific wanted to charge $300+ for a serial-to-ethernet adapter and another several hundred dollars for software that would publish the data to the web. We tinkered with the logger for a few hours and realized that it had a terminal mode. We decided to buy a really long serial cable for $10 and write a simple Java program using an open-source library from the Arduino project (called Processing) to communicate with the logger in this mode and parse its output into a text file, bypassing the proprietary solution altogether.
  2. The terminal mode was intermittently unstable. We could not understand why the data logger would sometimes respond and sometimes not. With some trial-and-error and lucky guesses, we realized it simply had a very short time-out (3-5 seconds) between commands. We made our program poll more frequently (every second or so) and re-send the initialization sequence (5-6 carriage returns in quick succession) whenever the logger stopped responding. This appeared to work, but time will tell if it's stable over longer periods of time.

Discussion[View | Edit]

Hi, I'm a student at Swarthmore College where we use a CR1000X in our Solar Lab. I have been looking into the posts on Appropedia about the CR1000 set up and the limitations of publishing to the web. We are also struggling to find an affordable and low-tech solution. I am curious to follow up and ask if more details on the solution for publishing to the web was found for this system, we would love to adopt it. Thanks, Chris ——The preceding unsigned comment was added by Cstone3, 11 March 2022

Low cost data logger.jpg
@Cstone3 Hi Chris! What kind of logging are looking to do? I don't know if this helps you but I have built some low-cost data loggers using the lowest-cost Arduino boards available (these cost a few dollars). The photo here is an example of a logger with an SD card shield used to log air humidity (it was my testing application). —Emilio (talk) 23:38, 11 March 2022 (UTC)
@Emilio Thanks for your quick response! We already have a data logger we use at my college, the CR1000X, which is very similar to the CR1000 that is mentioned in the original post. We use it to connect to two pyranometers (tilted and horizontal irradiation) and a pyroheliometer (direct irradiation) and it has been a part of the school's lab for several years, the only thing is that we would like to be able to publish this information of solar availability. For example, a graph that displays live information from our data logger and would allow anyone to download .csv's of the data. The lab is used for experimentation to help students learn about how solar systems engineering is done, so we have three pairs of different solar panel models for testing and measuring the performance of as well. It is true that retiring our system to use an Arduino or other micro-controller set up may be effective, though that is not currently within the scope of work. The original post implies it may be possible to augment our system with an Arduino to achieve the ability to publish our data. Cstone3 (talk) 23:51, 11 March 2022 (UTC)
@Cstone3 Sorry for not responding earlier! I see... I do not have experience with this datalogger. I'm noting that it has an Ethernet port, and you can access it through IP communications. Since what you need is a computer, maybe this resource could work?Emilio (talk) 22:29, 19 April 2022 (UTC)
@Emilio no worries. yeah, Lonny put me in contact with Roger and I was able to connect to the serial connection (RS-232 was not successful). By doing so, I can, for example, type 7, and the serial response will give me the instantaneous variable output. We were hoping to use python or matlab and the serial connection to manipulate the data further, but were unsuccessful in communicating with the datalogger in such a way. I've also looked through a number of papers including the one you attached, however, I believe my professor intends to put this exploration on hiatus for the time being. I'll try bringing up future research by other students using an RPi and the IP address as mentioned at the end of the paper. Cstone3 (talk) 01:21, 20 April 2022 (UTC)
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