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Hi Sara,

I worked through this and everything compiles correctly now!  Thanks for your help.

I did wonder about the linter in Atom.  From what I have read there seems to be an issue with linters working with .ino files in Atom.  Have you guys found anything that works?

James

Thanks Jim. Ohm’s law – copy that! 🙂

The coulomb counter I’m using is from Sparkfun. It pulses one of its pins low each time that 0.614 coulombs of charge have passed through its sense resistor. Very easy to use.

Regarding the decreasing current: Is it possible that the battery’s internal resistance is increasing as it discharges, and this…[Read more]

Couple of clarifications:

• The discharge is a fixed load of 22Ω so ohm’s law works!
• My question is why is the Mayfly station drawing less and less current as it approaches 3.3 Volts?  Yet the 4G modems continue to work and upload the data.
• I believe that Shannon said that some older sd cards tend to cause current draw during sleep mode.  Ma…

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Thanks @srgdamiano! I will try again when I get home from work.

I am using Atom with PlatformIO. How do I turn the linter tools on? thanks also for the tip on ‘extVoltage’. I was going to write a function that did the same thing as the unnecessary repetition was starting to bug me!

James

If you’re still using the Arduino IDE, you might consider switching to VSCode (or Atom) with PlatformIO.  I know VSCode seems very scary to start with, but if you’re writing new code or even just copy-pasting chunks the linting tools it provides are invaluable.  When I created a project for your code in VSCode, it immediately highlighted the e…[Read more]

I think you just missed commenting out one more reference to the EEPROM in line 144: EEPROM_read(KVALUEADDR, Kvalue); //1.0 means no change to raw readings. Just commenting or deleting that line should fix the compiler error.

If you wanted to, you could use the “extVoltage” sensor in ModularSensors with >1 reading do simplify all your code for…[Read more]

Data plan prices are kind of a hard thing to put an exact total on, since it varies depending on various factors the station owner can choose, like cell carrier and transmitting interval, but I can give example costs for our typical configurations and deployments.  For example, most of our stations transmit around 10 parameters every 5 minutes,…[Read more]

Hi Jim,

Thanks for sharing your findings; this is interesting and useful for me. I’ve been thinking about battery capacity and power consumption issues recently and have used a coulomb counter to measure the charge consumed by a Mayfly/sensor test configuration. I hope to share my findings soon. One question on my mind is: how many amp-hours can…[Read more]

The bottom cut-off (below which the logger will only sleep) exists so that when a near-dead or completely dead solar-powered logger suddenly sees sunshine it gives the battery some time to charge before putting any load on it.  Otherwise the logger can get in a loop of repeatedly resetting when the just-barely-charged battery browns out with any…[Read more]

We typically code our stations to cutoff modem transmissions at 3.45v, and file operations at 3.4v.  The Mayfly will stop operating around 3.35v, so if you set your modem cutoff too low, then you’ll stop transmitting AND stop collecting data on the memory card at the same time.  By setting the modem cutoff a little above the memory card logging c…[Read more]

I’m confused by your tests and your results.  The purpose of having the voltage threshold for data upload is to conserve power for the sensors so that data will still be *collected* as long as possible, even if that data isn’t reported online.  Of course, decreasing the minimum threshold for powering the modem will increase the amount of time t…[Read more]

I’m sorry I’m late to this.  But @mbarney the problem with turning off power to I2C devices isn’t universal.  It depends on how your external I2C device is wired.  If the SCL and SDA of your external device are directly pulled up to the incoming Vcc, then when you turn off the switched power, suddenly the system SCL and SDA will be pulled *<…[Read more]

Hi Scott,

Thank you for this, and apologies for not getting back to you sooner.  For some reason I wasn’t alerted to your reply.

This is exactly what I was after!

Thanks again.  I will let you know how we get on.

James