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I’ve had a simple system soak testing.

It has an Xbee WiFi, LiIon 500mA, measuring MayflyVbat and ADS1115 extVbat. When the extVat voltage is >=3.85V it will

Logger dataLogger.logDataAndPublish();

and when below <3.85V only

Logger dataLogger.logData();

I’ve used the 3.85 threshold as I found the Mayfly was resetting when the WiFi turned on…[Read more]

So just to add some more characterization measurements.

I’m using a Mayfly Sn 20395, and attempting to characterize what range the readings from the Mayfly ADC Vbat are linear when it is only powered from Vbat.  I’ve put a resistor network on the extV to the LiIon batter, to halve the voltage to keep it within the Vcc range for the ADS1115.…[Read more]

Hi Matt, power is a challenge. I always think of those battery watches with a tiny battery in them. How do they do it.

My take is this. a) what is the minimum energy its going to collect across the really low solar months  eg winter months  b) What is the longest I want the system to run for with no solar power – that is usually a storm of some s…[Read more]

Thanks for sharing this good work, Neil. This does get technical, and I have a lot to learn, but your experiences will be helpful. For the short term, our team is primarily interested in knowing approximately what the limits are, for a given site, for a given set of sensors, whether the available solar power will keep our stations running for the…[Read more]

I should note, that for real world solar panels, the power supplied by the panel is  dependent on the solar photons received. For a  slow change in power delivery some circuits have some strange behaviour.  I’ve had a Mayfly with an LTE  module, and a 2Ahr battery, and at sunset it started resetting. It continued resetting for about 30minutes unt…[Read more]

I’ve been using the INA219 and contributed sensorsTINA219
I’ve used it for measuring a working Mayfly on the lab bench. For  field monitoring, I would think you need a coloumb counter ~ eg LTC2941 ~ I have an adafruit version but haven’t tried it.

On the lab bench I have the INA219 on a separate Mayfly with console and put in in series with the…[Read more]

That’s correct, the main reason the ADS1115 is on the Mayfly is to give you much better resolution on analog measurements (16-bits versus the ATmega1284’s 10-bit ADC). It can also handle a much faster sampling rate and can take differential measurements. The standard ATmega analog inputs are still available for you to use, they’re just only…[Read more]

Thank you @shicks.

That set me on the right track.  I think I can figure the rest out from here.

Just to make sure my understanding is correct, the ADS1115 is included in the Mayfly because it provides more voltage resolution than on standard analog pins, i.e. it allows for finer divisions than 0-1023 bits?

Thanks for your help.

James

Hi Anthony,

I picked up a couple of the MultiTech mDotTM LoRa radio modules. Can you share any example code you have for getting them communicating? or do you need anyone to help test the ModularSensors library additions you are working on? I am happy to test and report back with any issues.

Thanks,

Dale

Because the ADS1115 is a separate chip, you don’t have to declare the ADS1115 input pin numbers as A0, A1, etc. You just call them 0, 1, 2, or 3.

In your code, you can remove line 8 since you’re declaring an INT that you aren’t actually using anywhere. Or you could keep the line and just change ‘A3’ to ‘3’

Then in line 26, you can either…[Read more]

Thanks for the info Shannon.  I will check out the GPRSbee and sd card to see if they are the cause of the 2.4 mA draw when in sleep mode.  I’ll try a new Mayfly board next.

Without having been to that station myself, it’s hard for me to guess why that station is having more battery trouble than your other ones. I’m guessing maybe it’s more shaded, or possibly the solar panel isn’t pointed in an optimal direction? You could also try putting a voltmeter on the panel on a sunny day and make sure it’s putting out…[Read more]

@shicks

I checked my GMI_EC5 station that I mentioned above that was not keeping up and I measured about 2.4 mA current draw when the mayfly is in sleep mode.  I thought it should be close to zero when in sleep mode.

Any thoughts Shannon?

Interesting, thanks Jim. I’ve been wondering whether one of our problem stations has a charge controller chip that’s impeding its charging, so we’re preparing to swap out the Mayfly to troubleshoot.

-Matt