[Shannon Hicks]

If Windows doesn’t find the drivers automatically, you’ll need to install them manually. I just installed the drivers on a dozen new Window 7 machines and WindowsUpdate was able to find the correct driver each time. The FTDIchip.org site has instructions for how to do that. Note that there are 2 different drivers that need to be installed: one is the FTDI drivers, and the other is the virtual com port (VCP). If the installation failed or didn’t go properly, the FTDI website has some instructions for how to update the drivers manually. If you check DeviceManager, do you see the virtual com port listed or any warnings under the ComPort or USB sections?

Another alternative is if you already have an FTDI device, like the Adafruit FTDI-Friend, the Sparkfun FTDI Breakout, or a cable with built-in FTDI, and you’ve used it with other boards, then just use that to program the Mayfly via the FTDI header.

[Shannon Hicks]

Try this DHT sensor example. It shows you how to power the switchable Grove connectors, and you can just replace the DHT stuff with some SoftwareSerial code to use either the D6-7 or D10-11 pins for the serial comms.

Or you could use the D4-5 connector, the default jumper sets it to 3.3v constant. The D6-7 and D10-11 sockets are always switchable, either 3.3v or 5. Only experienced users should use the 5v option, since they will need to insure that the sensor or other peripheral device is either one-way or has level converters so that the higher voltage required by the remote device won’t get fed back to one of the Mayfly digital pins.

[Shannon Hicks]

Thanks for the information JimMoore. I’ve personally used several dozen of the microUSB cables from that same shipment and haven’t had an issue with any of them, but we’ll make a note of it for future orders. I checked out the board that JohnSmutny had the issue with and it was indeed a bad mechanical contact inside the slide switch that caused the intermittent problem, but only on the pole that controls power to the FTDI circuitry.

[Shannon Hicks]

Yes, if you’d prefer to use the hardware D10 interrupt, just cut the trace and solder a jumper over to the D10 pin on the header row. Then you can use “INT2” as the interrupt.

[Shannon Hicks]

The Mayfly has 3 hardware interrupts, D2, D3, and D10. Since the first two are part of the serial UART, that only leaves D10 as the only available hardware interrupt. On the Mayfly v0.3 board, the RTC is connect to A7, so you have to use a “pin change interrupt” library to handle an interrupt from something other than one of the hardware pins. This can also be helpful if you’re looking for a trigger signal on any input pin.

The SODAQ pin change interrupt library works great for this: https://github.com/SodaqMoja/Sodaq_PcInt

You can also read more information about how SODAQ handles the interrupts on the Mbili, which is similar to the Mayfly. http://support.sodaq.com/interrupts/

I’m working on some sample Mayfly code for handling the pin change interrupts, I can hopefully post it soon, but the SODAQ links should help you in the meantime.

[Shannon Hicks]

John is right, just about any sensor you find should be able to work with the Mayfly, though you might have to add some interface circuitry or adapters depending on the power requirements and communication protocol of the sensor. I’ve got Mayfly board working with digital output sensors (either TTL, RS232, or SDI-12 outputs) and analog output sensors, and I’ll be posting code examples soon. It’s also possible to use 4-20ma output sensors if you have an interface, but we don’t currently use them in any of our active projects so maybe someone else can chime in with their experience with using 4-20ma sensors.

As for the types of sensors, we normally use research-grade high-quality sensors for turbidity, conductivity, pH, dissolved oxygen, etc. While the cost is relatively high compared to the low cost nature of the Mayfly, we prefer them because of their precision and dependability. We are also experimenting with different low cost sensors for measuring those parameters and hope to have some results to share later this summer.

[Shannon Hicks]

The power switch on the Mayfly is a DPDT switch that has 2 functions. One pole switches the power input line to the main processor power rail, and the other other pole switches the power supplied to the FT232RL USB chip. So if there’s a defect in the switch mechanism on only one of the poles, it’s possible that the Mayfly will still power up and perform normally but the power for the USB converter could be intermittent. If you’re continuing to have problems with the switch, I’ll send you an email about how to resolve this.

[Shannon Hicks]

I’m not aware of any other issues with the power switch or USB connectivity. What operating system are you using? And did you buy the Starter Kit that comes with it’s own microUSB cable, or are you using your own cable? I’ve had connection issues with microUSB jack/cable combinations on other devices, so maybe try a different cable and see if that helps. Do you have an FTDI cable or adapter board that you could use to power and program the Mayfly to see if touching the power switch has the same effect?

Another thing to troubleshoot whether it’s communication or power related would be to put a sketch on the board that lights both LEDs constantly, then disconnect the USB or FTDI cable, and plug in a battery to the LiPo jack. Then you can turn the switch on and keep an eye on the LEDs while touching the switch to see if perhaps there’s a loose connection in the switch.

[Shannon Hicks]

FWIW, in the past I’ve had a few times where the DS1307 clock on the Adafruit shield would reset to some random time in the past or sometimes even in the future. If I remember right, I think it usually happened whenever I was trying something new with the hardware, so I just assumed it was sensitive to shorts or other weird electrical gremlins. It has only happened a few rare times with the DS3231 on the Stalker in the past couple years. I stopped using the Adafruit shield for deployments where timing really mattered because the DS13007 is so inaccurate at either high or low temperatures that our timestamps would get horribly fast or slow during the either the winters or summers. But if you’ve got a GPRS unit on the logger, you could just grab the time from a time server occasionally and resync your clock every few weeks.

[Shannon Hicks]

I will be assembling a couple of Ultrasonic loggers with a colleague in a few weeks and we will document the process and post it on this site. However, we’ll be using the Seeeduino Stalker v2.3 board, so you’d have to modify the plans if you use a different board, or if you’re lucky you might be able to find a spare v2.3 board somewhere online.

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