Shannon Hicks

I haven’t had a chance to make a table of all of the power usage data from my tests, but here are some of the more important measurements:

Mayfly current when board is powered and idle: 6.5 mA
Mayfly current when MCU put to sleep: 0.27 mA (or 270 uA)
Current when asleep with microSD card in the socket: 0.43 mA (or 430 uA)

Check out this ultrasonic sensor example I just posted. It shows how to read the serial output of a Maxbotix sensor. I like to use the MB7386 and MB7389 sensors because they have the TTL output that can be read directly by the Mayfly. The MB7360 you mentioned only has RS232 output, so you’ll need a RS232-to-TTL converter between the sensor and…[Read more]

We have had very good results with the GPRSbee module from SODAQ. It’s a 2G board and SODAQ also has a new 3G board with the same Bee footprint so it could also work with the Mayfly. We have deployed many stations with the GBRSbee board along with a SIM card from a company that offers a low-cost data plan, so the loggers can push data into our…[Read more]

I have done some thorough testing of the battery holders on the original v0.3 boards and the new v0.4 boards and found that it’s the texture of the bottom of the battery that makes the difference. It appears that one brand of battery might have some problems making good contact with the board, but this isn’t limited to the Mayfly. I tested 3…[Read more]

See my latest blog post for information about exchanging the v0.3 Mayfly boards for the new v0.4 boards. I will also be emailing all of the Amazon customers today with information about the exchange.

Pins 10, 11, 12, and 13 on the Stalker are used by the SPIbus, so if you’re want to use the microSD card socket, you can’t use those digital pins for anything else. It’s been awhile since I looked at the specs of the Stalker, but I think there are very few free pins. That’s one of the reasons we stopped using it and created the Mayfly. And the…[Read more]

If you measure 3.3v on the Sw_5v pin, then unfortunately you have a board with the incorrect regulator. There’s no way to get your board to generate 5v unless you replace the regulator. While it is possible to replace it if you have the right tools and you have experience removing and replacing a SOT-23 surface mount device. However, we have…[Read more]

Did you put a solder blob across the pads of P3 on the back of the board? You’re using INT0 in the code, so you need to close the pads that connect the RTC interrupt signal to pin D2, and according to the Stalker 3.0 wiki, that is accomplished by shorting out P3. I have not used a Stalker 3.0, but I know on the Stalker 2.3, the board would go to…[Read more]

I’m not sure why your code didn’t post correctly. Maybe because you attached it as a .ino file. Try just pasting it into the “code snippet” box when you’re typing a reply. Just hit the “Add Code Snippet” button in the row of buttons right above the text box, past your code into the window that pops up and choose “Arduino” from the Language…[Read more]

I’m glad it worked. We’re working on switching out all of the Amazon inventory with new boards and we’ll be testing each of them first for proper battery connections. It can sometimes be hard to solder to a battery which is why I suggested doing the board first. The next run of boards will have a different battery holder and board footprint so…[Read more]

I just did some more testing with a dozen boards. Out of all of them, I found one that exhibited behavior similar to yours. It looks like the green solder mask paint is thick enough on some boards that it is preventing the battery’s negative side from sitting completely flush against the circular ground pad on the Mayfly board. You can easily…[Read more]

I just posted a helpful serial communication sketch. Try that and see if it works for you.

Some Bee modules might need additional signals or control lines to work properly. That’s why many of the Bee socket’s pins are connected to some digital pins. For example:

Bee CTS –> D19
Bee RTS –> D20
Bee DTR –> D23
Bee RI or Assoc –> A5 (via…[Read more]

The Mayfly has two serial UART ports. They are designated 0 and 1, and also called TXD0/RXD0 or TXD1/RXD1. When referring to them in the sketch, one is called “Serial” and the other is called “Serial1”.

On the Jumper Settings page, it states:

SJ8: Connects the Bee socket TX signal to Mayfly TXD0 (UART 0) or TXD1 (UART 1). Default position…

[Read more]

That’s odd that you measure 3v on the battery alone but nothing when it’s installed in the holder on the board. Even a mostly-dead battery should read something besides 0.000v. You usually only see that if there’s a short circuit somewhere on the board (which it doesn’t look like there is, from looking at the photos), but the battery would have…[Read more]

That’s odd that you measure 3v on the battery alone but nothing when it’s installed in the holder on the board. Even a mostly-dead battery should read something besides 0.000v. You usually only see that if there’s a short circuit somewhere on the board (which it doesn’t look like there is, from looking at the photos), but the battery would have…[Read more]

Can you take a focused picture of just the back of the board and one of the front?

I haven’t had any problems with the Mayfly boards not retaining the time. I just tested 2 boards that have been on my bench for several months without any external batteries (other than the CR1220) and they both still knew the correct date and time. I then got out 5 new boards, inserted new CR1220 batteries, and then programmed them with the…[Read more]

Yes, I’ve done a variety of power measurements with the Mayfly board, so I can publish a table showing the different options. I’ll put a link to it here when the page is posted.

The Atlas Scientific sensors work fine with 3.3v VCC, so just connect the 3.3v pin on the Mayfly header (either the D22 switched or the constant 3.3v VCC pin) to the Atlas board along with a ground line. Then choose 2 free digital pins for the comms, like 6 & 7 or 10 & 11, and edit the first few lines of the sample code to change from the pins 2…[Read more]