dan@wachusett

Yes, the board seems to perform just fine while only 1 card is inserted. There are most definitely electrical irregularities when 2 cards are in at the same time! I had erroneously assumed that the horizontal card was for uploading sketches and that data would be logged to the second (vertical) microSD card, which could be extracted easily to…[Read more]

Yes, this is a brand new board.
The microSD card is not the issue – I have switched cards and get the same result. Both cards work fine if used alone.
I believe the problem lies in the circuitry between the two SD card slots… When only 1 card is inserted (either slot) the board powers on. If both slots have microSD cards inserted simultaneously…[Read more]

I was able to fix the issue, though I’m not sure at all why it worked. When I have a microSD card in extra slot for datalogging the Mayfly board will not even power up. As soon as I pull the microSD card out the LED lights blink, the red one stays on and all is well. This seems to be a rather serious issue since the entire purpose of the mayfly is…[Read more]

Update…
After some searching on other forums it seems the sketch upload error is just a communications error. Is there any reason why I have previously been able to upload sketches to my board and send output to the serial monitor, but now I cannot? Could it be a driver issue?

I did not install the FTDI virtual COM port (VCP) driver because…[Read more]