[Jim Moore]

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.  Maybe this is what is happening.
• Matt- I am interested in your coulomb counter?  Where can I get one or is it home brew?
• I have learned that not all Li-ion batteries are equal in terms of stated Ah capacity.  I bought some from Amazon rated at 4.5 AH yet they were less than half the size of the 2.5 Ah batteries I got from Adafruit!  And the JST connector polarity was reversed!

Cheers

-jim

[Jim Moore]

I am using the same hardware with my Low Cost EC stations   which is set up for UART mode but I have since upgraded to I2C mode when I added the 2G modems.  I am using the sensorex probe for the EZO EC which has an integral RTD which I read thru the analog input.  I think its only about a $30 premium for the the RTD option.  Maybe there are some ideas in my blog that will help.

[Jim Moore]

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.

[Jim Moore]

@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?

 

[Jim Moore]

@mbarney

I have the same issue.  I have my LEC stations (GMI_ECxx) running with 2G cell service and I did have one station that the solar charge chip failed and caused battery to drop below the 3.55  volt threshold for upload.  However GMI_EC5 seems to be getting a charge during the day but is still not keeping up.  I attached a screen from MMW TSA and you can see the drop-off in voltage on this sensor station vs the others.  I also noticed a general drop off which I presume is amount of daylight.  I am using the 2.5 AH batteries.  I plan to check current draw to see if it is abnormal or caused by poor cell service.

Attachments:

1. 

   GMi_EC-battery-log.jpg
   

[Jim Moore]

@shicks

I checked Amazon and finally discovered that “envirodiy mayfly protoshield” works for a search.  Did not have envirodiy in my search query.

I just bought the last one so guess time to restock

[Jim Moore]

@shicks

I checked Amazon and finally discovered that “envirodiy mayfly protoshield” works for a search.  Did not have envirodiy in my search query.

[Jim Moore]

@shicks
I just checked Amazon and no Protoshields showing.  I guess shipment processing isn’t one day turnaround!

[Jim Moore]

Any updates on the availability of the Protosheilds?

[Jim Moore]

Thanks.  I am using the FTDI port and wiggled some plugs, etc and now is loading ok.  I assume when I was getting that error the mayfly was plugged in and turned on because when I attempt to load with the pwr switch turned off I get the following error:

Uploading .pio\build\mayfly\firmware.hex

avrdude: ser_open(): can’t open device “\\.\COM4”: Access is denied.

avrdude done.  Thank you.

*** [upload] Error 1

I guess a bad connection somewhere.

[Author]

Posts