Shannon Hicks

The ADS1015 ADC has a programmable gain so I since I was looking at signals I knew were below 2v, I used the GAIN_TWO setting to give me a range of +/-2.048V. You can select anything from a gain of two-thirds to 16, which is a range of around 6v (but realistically Vcc of 5v for an Uno) down to 0.25v.

For accuracy, the error is supposedly less than one LSB and very stable across the -40 to 120 degree operating range. Years ago I found that the Arduino’s on-board ADC is horribly inaccurate during either extremely hot or cold temperatures in the dataloggers we deployed outside, so we started using the ADS1015 in all of our loggers and have been extremely happy with their performance.

If you’re using the DS3231 library, you can use the following code:

DateTime now = RTC.now(); //get the current date-time
currentepochtime = (now.get()); //seconds since 1/1/2000

Look at the “now” example that comes with the DS3231 library to see the whole sketch.

What kind of pressure sensor are you using? You can usually get temperature-compensated ones for only a slightly higher cost than non-compensated ones.

I have dozens of Seeeduino Stalker v2.3 boards, and we have been using them for a few years now. But they were discontinued last fall and replaced with the new v3.0 model. We will not be using the v3.0 version, for a variety of reasons, so we are currently testing and evaluating other board options. The Fio is only handy because it has an Xbee socket, but it has no RTC, solar charger, or memory card slot. We haven’t developed a tutorial for how to build a stalker 2.3 based logger since those boards are nearly impossible to find now.

That photo was from a temporary test setup, so I don’t have more pictures. I moved the PVC pipe to a more secure mounting to survive higher flows. The ultrasonic sensors, along with all of our other sensors and logger circuitry, are performing perfectly this winter, even with air temperatures below 0 degrees C a few times. I’m still running a few experiments with various ultrasonic setups, so I’ll share that data when I’m able to make a conclusion.

We will post the Arduino code on our Github site soon along with a simple block diagram of the wiring. I could also do a tutorial on the hardware assembly, but it’s actually quite simple. I will update this post when the instructions are published.