Category Archives: Developing other sensors

I am developing an entire family of open source loggers for use in caves and underwater environments.

Enhancing Arduino ADC resolution with Dithering & Oversampling

While I was figuring out how to read thermistors, I came across claims that you can improve the resolution of any Analog-to-Digital converter with a technique called oversampling & decimation. I had already doubled the number of ADC bits covering my target temperature range by powering a thermistor divider from the rails … Continue reading

Posted in Developing a Temp.Chain, Developing other sensors | 2 Comments

Field Report 2016-07-09: I2C pressure sensors work on 20m cables!

With the term prep taking up everyone’s time, I almost forgot to post about the wonderful field season we had this summer.  We really covered the bases on this one: from surface loggers, to cave sensors, to new deployments out on the … Continue reading

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Using the Arduino UNO for Data Acquisition

I recently picked up a ADS1115 breakout board, and it was fairly easy to use that with the serial data plotting capability of the Arduino IDE. It’s not often that something works this well on the first try, and I thought I would post about using  the combination as a kind of … Continue reading

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Better Thermistor Readings with an Arduino: Series Resistors & Aref

Up to this point I’ve been using IC thermometers (TMP102, DS18b20, etc) because they are easy get going, and seemed to offer better resolution than I could get out of the Arduino’s humble 10bit ADC.  But several of the projects I’ve been working … Continue reading

Posted in Developing a Temp.Chain, Developing other sensors | 2 Comments

Field Report 2016-03-16: Rain Gauges Over Reporting

One of the first priorities was a trip out to Rio Secreto to service drip loggers. Data from the last season confirmed that all of the loggers are good for at least 6-8 months, so we now have the option of servicing … Continue reading

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Field Report 2015-12-08: The Logging Rain Gauges Work!

We managed to squeeze in a short  fieldwork trip before the end of the year, and the growing number of loggers at Rio Secreto put that cave at the top of our list to give me enough time to service all the units.  It was also important that … Continue reading

Posted in Developing a Drip Sensor, Developing other sensors, Expedition Reports & Updates | Leave a comment

Measuring Humidity in a Cave: A Masons Hyrgometer Experiment

I’m finally getting the next generation of Pearls together for their pre-deployment test runs. The new underwater units will all be in 2″ enclosures and perhaps it’s just me, but I think the slimmer housings make them look more like professional kit. These units … Continue reading

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