Comments

Author Comment Last activity Moderation
warren "This is very cool! I do wonder if TDS is going to be consistently correlated with conductivity -- i may just not be well informed but isn't it poss..." | Read more » 3 months ago
warren "Hi @alejobonifacio i wonder if there is an 'ideal' range if we can use resistors or capacitor sizes to shift that to our looked-for "search range" ..." | Read more » 3 months ago
warren "Thank you for the links and the explanations!!! " | Read more » 4 months ago
warren "Hmm... I guess it seems like a tough setup for my skill set. What does the microwave version look like? " | Read more » 4 months ago
warren "https://www.sciencedirect.com/science/article/abs/pii/0039914070800819 " | Read more » 4 months ago
warren "Interesting. It's like a high power version of this? https://www.ebay.com/itm/324819370181 Does this take high voltage to run? " | Read more » 4 months ago
warren "Definitely these can be dangerous for the eyes. The LEDs seem nice because they are a little less 1800s feeling than those tiny tiny mercury bulbs!..." | Read more » 4 months ago
warren "This seems like a great application and very feasible. Indeed the color/sensitivity range of anthocyanin in cabbage juice is really huge. 533 is in..." | Read more » 4 months ago
warren "What about if it fluoresces under UV light? Could that help? Though some natural substances fluoresce too. " | Read more » 4 months ago
warren "Hi @Ag8n - thanks, i'm thinking of an activity which young people could do in a group, over the course of a month or so, to create a map of a water..." | Read more » about 1 year ago
warren "De acuerdo, gracias! " | Read more » over 2 years ago
warren "I think there is a little screw that can be turned to "tune" each sensor board, so I wonder if you could put both in the same sample and use a smal..." | Read more » over 2 years ago
warren "Maybe we could do both sound and light? That way it is adaptable for different abilities too. I don't know if we could have one port drive a light..." | Read more » over 2 years ago
warren "So, i realized entering control-shift-; in a google spreadsheet enters the exact time/date in a cell. Maybe we can modify the Arduino code to send ..." | Read more » over 2 years ago
warren "That is really odd. I tried a couple other things but can't figure out why this is happening. In theory it should just be pressing the tab key betw..." | Read more » over 2 years ago
warren "Hmm, the script is: function onEdit(e) { var val = e.range.getValue().toString(); if (val.indexOf('_now') !== -1) { e.range.setValue(Dat..." | Read more » over 2 years ago
warren "Oh, it looks like the sensor is sending "_now" instead of "now"... I wonder is it possible to modify the spreadsheet script to match that? " | Read more » over 2 years ago
warren "Folks at NASA AREN (#aren) sent this over -- a smartphone method for water color, interesting! http://misclab.umeoce.maine.edu/research/HydroColor..." | Read more » over 2 years ago
warren " " | Read more » over 2 years ago
warren "I did this! My first error it was a silly mistake - the yellow/red/black cable was plugged in backwards. "apparently" it makes a difference which ..." | Read more » over 2 years ago
warren "Hi Will! What do you think of a really basic version of this, shipped assembled, something like a "Simple Turbidity Sensor"? This could help us ju..." | Read more » over 2 years ago
warren "Looks like there is an issue with reply by email, or possibly the list => email system, but Alan Marchiori responded on the plots-waterquality l..." | Read more » over 2 years ago
warren "Thanks! I'd guess that's true of some of #dfrobot / #knowflow sensors too, since several of theirs ship with buffer and are off-the-shelf probes co..." | Read more » over 2 years ago
warren "For one, these sensors don't seem to log data, but they're so easy to use otherwise that they seem pretty good for a workshop, for example! cc @ch..." | Read more » over 2 years ago