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@shicks
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ArnoudC, I’m not sure which Maxbotix sensor you’re using, but on the models we usually use, it’s pin 5 on the sensor that gets connected to the Mayfly digital pin (pin 5 in my example code above, but you can make it whatever you want). I think on most of the Maxbotix sensors, Pin 6 and 7 are the power and ground pins, and pin 5 is the serial TTL or RS232 output pin that you can easily read with the Mayfly using the capture code above. Sensor pin2 is the PWM output and pin3 is the analog signal, but I prefer the serial output. The code above only works for capturing the sensor serial output. Check the datasheet for your sensor model to verify that these are the correct pin numbers.
You can connect the sensor power and ground pins to any power or ground pin on the Mayfly or any other Arduino board. The Maxbotix sensors draw just a few milliamps of current so I usually just connect the sensor power pin to an available Mayfly digital pin and switch it high or low to control the on-off cycle of the sensor, which is handy for situations where the logger is programmed for sleeping between measurements. However, I have found that some of the sensors don’t like having their power pin connected to the switched 3.3v bus on the Mayfly. So if you’re running the Mayfly without sleeping, just connect the sensor power to the 3.3v constant bus. If you’re sleeping the Mayfly between sensor readings and you want to shut off power to the sensor, then use a digital pin to provide the power.
Marion, if you haven’t already found it, there’s a repository on the EnviroDIY GitHub page where you can download all of the sample sketches that are currently listed on EnviroDIY, as well as some sample sketches for some workshops we did that use Grove sensors. I’m working hard to post some additional code online this week:
This topic got answered in another thread, but I’ll post the answer here since it’s important:
After extensive testing with 8 of the latest versions of the IDE, I can confirm that the EnviroDIY board configuration file that is currently posted on Github will work with Arduino IDE versions 1.6.5 through 1.6.12.
There was an update done to the IDE starting with version 1.6.11 that caused an incompatibility with the Mayfly configuration file on GitHub. But I just updated that config file and tested it with version 1.6.11 and 1.6.12, and everything is working fine now. Thanks for pointing out the issue, Paul and Marion.
2016-10-18 at 3:16 PM in reply to: Problem with Arduino IDE loading Mayfly board data from github website #1757After extensive testing with 8 of the latest versions of the IDE, I can confirm that the EnviroDIY board configuration file that is currently posted on Github will work with Arduino IDE versions 1.6.5 through 1.6.12.
There was an update done to the IDE starting with version 1.6.11 that caused an incompatibility with the Mayfly configuration file on GitHub. But I just updated that config file and tested it with version 1.6.11 and 1.6.12, and everything is working fine now. Thanks for pointing out the issue, Paul and Marion.
Which ones are you interested in? I was hoping to get some feedback from other users on what type of prototype shields they might like or what features and pin breakouts they might like to see.
2016-10-12 at 8:59 AM in reply to: Problem with Arduino IDE loading Mayfly board data from github website #1746This is interesting, thanks for the information Paul. I haven’t encountered this problem with any of the recent Aruino IDE builds as of a few months ago, but I’ll try it with the latest one and see if I can resolve the issue.
That looks like a great sensor. Powering the sensor from the Mayfly battery is probably possible, but at 100ma, it’s toward the upper end of the max operating current of the 5-volt boost circuitry, but it looks like you could power it from either the constant 3.3v rail or using the 3.3v switching circuitry. The bigger issue would be if you wanted to run the sensor continuously or if it’s only going to be sampled for short bursts, with longer power-downs between samples. If you power the Mayfly with a big (4000maH or greater) lithium battery or a pack of C-size batteries, you could get several days of continuously-powered operation. If you only use the sensor for a few seconds every few minutes, then you could get by with smaller batteries and a solar panel and unlimited duration. It all depends on the sample time and sleep duration.
As for measuring the output of the sensor, there are a couple different options. One would be to put the sensor output across a resistor divider that drops the 5v to 3.3v (i.e. a 10k and 20k resistor in series across the sensor output, so when the sensor outputs a max of 5v, the voltage between the two resistors is 2/3 of that, which is 3.3v). Or you could add a separate ADC board (like the Adafruit ADS1115 breakout board). Power the breakout board from the 5v switched output of the Mayfly and then it will be able to handle a max input of 5v. But you’d need to connect the breakout to the I2C port of the Mayfly, so you’d need to add some digital level-shifting on those 2 I2C lines to protect the Mayfly from higher voltage of the breakout. I’m sure there are a few other methods, but those are the two quickest and easiest.
When a Mayfly board is asleep, it draws around 0.27mA. If you have a microSD card in the socket, the card draws a little current on its own, so then the Mayfly draws around 0.43mA when sleeping with a card.
When the Mayfly is awake and idle, it draws 6.5mA.
Battery life in a deployment would depend on the size of the battery and what sensors or other devices you’re powering with the Mayfly. You can do some estimations at this site: Oregon Embedded Battery Life Calculator. Just plug in the above numbers for the Mayfly, your battery capacity, and information about the waking time.
I would highly recommend the GPRSbee Rev 6. It has a much easier (and more reliable!) method for waking and sleeping the GPRSbee than the Rev 4 board. Plus the Rev 6 has a u.fl antenna connector instead of the SMA that the Rev4 has, so it’s much easier to fit it inside the Mayfly enclosure. I’m deployed 6 Mayfly loggers with GPRSbee’s last week and will be putting in 3 more tomorrow. So I’ve got plenty of photos of the process and example sketches. I just need some time to publish the instructions when I’m not in the field doing installations! Hopefully I can post a couple basic sketches later this week with more detailed instructions soon after.
As for sources, we still plan to offer kits soon with the GPRSbee in them, but for now I’d suggest you order them from SODAQ or Seeedstudio.
What version of the GPRSbee do you have? The latest hardware version uses different code commands for toggling it on and off. I’ve successfully used the latest 3 versions of the GPRSbee with the Mayfly so I can send you the appropriate code for your model.
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