Umm, just to be clear, this is an open source science project and we are not selling anything - you have to get the parts yourself. Depending on where you buy them the logger costs about $10.
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Who would you say have been the primary course attendees? I.e. age, education, interest/field etc? How many of your loggers (of any version) would you say have been built and deployed in anger, would you say?
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Our primary audience is instructors of college undergrads. Their students can reasonably be expected to learn enough coding to adapt the device to different summer research projects. For example one student built more than a dozen of these loggers to monitor temperature in turtle nests. As to the rest of your question, Iām not sure what you mean by ādeployed in angerā? Why would anyone be angry about an open source science project?
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I mean, how many loggers would you guess were deployed because there actually was some data that needed to be logged, as opposed to as a learning experience for example, or for some other reason?
Thanks again for posting your loggers over the years.
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The EDU model described in that recent post is simplified specifically for learning experiences, so Iād estimate less than a hundred (?) of those classroom models have been deployed by students outside of the courses for real world research projects. I can only estimate because Iām not sure how many students have done research projects with our colleagues at other institutions who have also been using the EDU builds. And there have been different teaching models over the last 10 years, and other instructors tweak the design to their own course needs.
By comparison, just for Dr. Beddows research alone weāve deployed about 500 self-built loggers over the last decade. And thatās just one research project, and not counting all the commercial kit weāve also deployed. But those research builds are more complicated on software side, and we make very rugged PVC housings for them which is quite time consuming. A typical installation gets 5-10 loggers with various different sensors, and a research site will have up to 10 installations. So you go through a lot of units with a yearly turnover of at least 15-25% because the get damaged, or simply age out.
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I can relate to the difficulty of making rugged housings.
Out of curiosity, what would you do if you had to make 100 units per week, could you modify the design to accomplish that? Say your task was to seriously compete with Hobo on price, features, availability. Could you come up with a plan?
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Seriously? Aside from the fact that the answers to these questions are already obvious to anyone who knows what they are doing - if you are only here to take ideas from people who are actually contributing to the open source hardware movement, so you can turn them into commercial products for your own profit, then you are in the wrong place.
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Iām not asking you to come up with a plan, but whether a plan could be come up with. Yes I am serious in considering this for the Ubiquity 25 initiative. I would normally prefer a project which didnāt have to compete with an incumbent, just because itās less work, but Iām not averse to competition. Have a think. Or not.
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Ok, after reading that I can see that you meant well so I apologise for my harsh tone.
However, please remove our project from consideration for your initiative.
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Happy to see the new logger mentioned in the nerd press:
https://twitter.com/arduino/status/1736145734670451117
However, interest on reddit is essentially zero. Even the response on r/ScienceTeachers is usually something like āBut you didnāt explain what a ādata loggerā is or can be used for?ā
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Much of the existing information on sensor calibration assumes a certain level of pre-existing equipment/capability. This creates a chicken & egg problem with white-paper procedures targeting accuracy that can not be achieved unless all the supporting parts of the system meet or exceed that same specification. From the beginning our project has been developing DIY solutions with that 80/20 point in mind and this NTC thermistor calibration hits that mark perfectly:
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Our 2-Module logger can be built for less than $10. However, for innovations in the open science hardware movement to have real impact in teaching & research, developers must also transfer knowledge about testing, calibration, and deployment. Our latest effort in that area is cross-calibrating an inexpensive Bh1750 lux sensor to measure photosynthetically active radiation. This was done with natural sunlight and one of the many online irradiance calculators so that the overall procedure is accessible to anyone no matter what level of resources they have access to - even if they canāt build one of our loggers.
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Hi 
, Iām just here to let you know that I will be giving a 3-day workshop about Cave Pearl Project Data Loggers in CĆ³rdoba, Argentina. Since this is a pilot, it will be exclusively for researchers at the Instituto de Diversidad y EcologĆa Animal (https://www.idea.conicet.unc.edu.ar/). I will share photos and results soon. Wish me luck! 
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Most excellent! I should warn that we are working with different instructors this fall, and the e360 codebase on GitHub is evolving based on the needs of their courses. Generally these updates are minor tweaks to improve stability/readability etc, but occasionally you will find a new feature appearing on the start menu during download. There are so many ways the base code could be optimized for low power, or faster execution, but we tend to stick to the most basic methods so that students who are beginners can understand & modify the codebase for their projects. Also, be sure to read the 2022 logger post for instructor-level background understanding. We tend to use the 30ml build from 2022 for deployment because all the connections are hard soldered, but for the e360 classroom build we have the students secure the modules to the mini breadboards with little drops of hot glue before taking them outside. Doing the same with the coincells makes the classroom logger much more robust to being knocked around outside as the students collect their data. And finally, many students do not thread the lids properly. Its critical that you check the lids are on the falcon tubes well before they put them under water!
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And one more thing, make sure you have 4-5 āknown goodā loggers that you built and tested yourself before the workshop so that you can get the IDE communications working. Having spare working machines also gives you a way to keep your students in sync with the labs activities, even if they discover an issue with their own logger. Then they can do the debugging after the main activity/ exercise. Be ready for 20% of $1 sensors like those BH1750 modules to be DOA - again having a few āknown workingā sensors before the workshop makes it easy to do process of elimination to identify when its bad hardware, rather than the students programming.
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Have the students label their logger with their initials using a sharpie marker as soon as it is assembled - even before testing. When you have 10-20 of them building loggers at the same time it is quite common for them to put their own logger down, read some lab instructions or get materials at the font of class, and then accidentally pickup someone elseās logger afterward, causing great confusion.
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Thank you for all your advice! For the code, I am using an old version from this year that I know works because I want to avoid surprises. We will test the hermeticity of all the Falcon tubes.
I have 6 Pro Minis, and I havenāt tested them yet, but I hope to get at least 4 loggers working. Due to resource constraints, I will work with 3 students per data logger.
I hadnāt thought about labeling the loggers, but Iāll do that. Thanks again!
If you have a working logger I suggest you test the latest build on GitHub on those. The most recent feature added is to calculate and display the logger run time with the sensor combination & sampling interval. Thatās really helpful to have when you only have the default 4k eeprom on the RTC module to store data. WRT parts, remember that cheap ebay parts have a 20% DOA rate, and people new to soldering often ruin a few more until they get the hang of it. So it itās at all possible Iād try to get more spare parts on hand before your workshop.
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