Shannon Hicks

Because the v0.5 board can now accept an input supply voltage up to 12v, I had to change the onboard voltage divider that’s used for measuring the battery voltage by way of A6. So the formula for reading the battery voltage on a v0.3 or v0.4 board is this:

rawBattery = analogRead(A6);
sensorValue_battery = (3.3 / 1023.) * 1.47 * rawBattery;

But…[Read more]

The Mayfly has 3 hardware interrupts. They are RXD1 (INT0), TXD1 (INT1), and D10 (INT2). To use the “attachInterrupt” function, you can only use the three hardware interrupt pins, and you have to refer to them as “0”, “1”, or “2”. So if you want to use the D10 interrupt pin, you’ll need to say the following on line 8:

attachInterrupt(2,…[Read more]

For anyone wondering about current Mayfly availability, I just received the shipment from the manufacturer today. I’ll be working to get them to Amazon by the end of the week. I sent in a bunch more of the protoshields today, next I’ll be sending lots of both the bare Mayfly boards and the starter kits.

Something I’m not seeing in your first sketch is where you declare what chipselect pin for the SD card. On the Mayfly it’s 12, so on line 42, change the “SS” to “12”. Then remove all the extra Serial.begin(9600) statements so there’s only one at the beginning of the setup function. And remove the RTC stuff on lines 11, 16, and 41. See if that…[Read more]

That’s a good question, thanks for asking: The new v0.5 board will handle an absolute maximum input voltage of 16v, so you should be okay. The 12v limit is the maximum “recommended” voltage. A charger for a 12v battery will output 13 or 14v, but it’s still safe to use that with the Mayfly (version 0.5 only). The older v0.3 and v0.4 boards get…[Read more]

The first couple things that stand out are this:

You don’t have to say “Serial.begin(9600)” more than once in your sketch. Just do it once near the beginning of your setup() function and that’s it.

You don’t have to set the date and time of the RTC every time you run the sketch. The way it is written in your examples means that the clock gets…[Read more]

I plotted the temperature and VWC on the same chart and you can see that they are very much linked together. Can you answer whether the sensor is completely buried in the soil, and if so how deep is it? If only the fiberglass tines are inserted into the soil but the rest of the sensor body is above ground and subjected to direct sunlight or…[Read more]

The graph looks more like a plot of temperature rather than VWC. Are you sure you’re plotting the right column of data? What are you using to actually record the data? Your sketch doesn’t output the data to a file or even print it in a easily-captured string out to the serial port, so I’m wondering how you collected multiple days of data. Plot…[Read more]

It would be helpful for you to attach a jpg of png image of your graph instead of a Powerpoint slide. You also can’t attach the raw .ino file to forum posts, but you can cut and paste it using the “code” tags in the post editor tools.

And on your graph, can you please label both the x and y-axis? I don’t know what parameter you’re graphing…[Read more]

Did you try running the PCsync.exe file on your computer with the Mayfly attached? That method worked for me last time I tried it. But I usually just use the adjust.ino sketch available in the Examples folder of the Sodaq_DS3231 library. Or you could use any DS3231 library since there’s nothing unique about the Mayfly’s RTC configuration.

I have confirmed that removing capacitor C4 will let the board continue to run without resetting when you open the serial monitor window. HOWEVER — This only works if you’re using the FTDI connector on the Mayfly (and a separate FTDI interface device like the Adafruit “FTDI Friend”) to connect it to your computer.

If you want to have this…[Read more]

The protoboards are now available on Amazon, via the URL I posted above. The Mayfly boards and the protoboards are selling fast, but we have a really big order of boards and accessories being assembled right now, so I hope to have the Amazon storefront fully stocked soon.

The protoboards went to Amazon almost 2 weeks ago, even ahead of the Mayfly boards, which got restocked online yesterday, so I think the protoboards should be available very soon, possibly today. Amazon used to get our inventory online very quickly last year, but lately they have been taking over a week or two to get products available after…[Read more]

Amazon shuffles the products between warehouses sometimes, and they list the items as “backordered” while they are in transit and unavailable for immediate purchase. They will show up as “available” when they’ve reached their new warehouse. Normally this kind of stuff isn’t apparent if there’s sufficient stock of the items, but it’ll show up at…[Read more]

Unfortunately the way Amazon does our item fulfillment, their system won’t allow backorders, and they only take orders when the item is in stock and physically in their warehouse. Sometimes they are very quick to get the item online and available, but other times it takes them up to two weeks to make our items available after I’ve shipped them.…[Read more]

That’s an interesting idea, I can try it with one of my testing boards later this week and let you know what happens (unless you’re good at removing (and replacing) SMD capacitors if it doesn’t work.)

Another option for connecting a sensor’s 3.5mm stereo headphone plug is to use these stereo jacks:
https://www.amazon.com/uxcell-Stereo-Female-Adapter-Connector/dp/B013D1U90S
Just strip the black, red, and white wires of a Grove cable and solder them to the corresponding terminals of the jack.

And the easiest way to do it is to use our custom…[Read more]

The boards are $60. They were in stock last week, but sold out very quickly. We are working to get more inventory soon.

The Xbee socket is powered from the main regulator, which can source 500ma. If your radio was having trouble drawing current, you’d probably see strange behaviour on the rest of the board. Are you powering anything power-hungry at the same time as the radio? What kind of antennas are you using? Xbee units have a default power setting of…[Read more]