SparkFun Forums

[tdahlstrom]

Hi, I've been been having an odd issue trying to use my OpenLog Artemis.

Hardware:
OpenLog Artemis (without IMU), v2.2 - DEV-19426
1GB microSD card - COM-15107 (first card)
32GB microSDHC card - SanDisk Ultra Plus (second card)
2AH Lithium Ion battery - PRT-13855

Issue:
With a microSD card inserted, the OLA will not power on. Instead, the PWR and STAT LEDs will flash once, then nothing. This happens regardless of whether it's running on battery or connected to my PC via USB. When connected to my PC, the COM port is recognized, but nothing else happens. Pressing the reset button has the same effect - both LEDs flash once, then nothing.

When the microSD card is removed, everything works normally - it powers on fine on battery, and when connected via USB and can open a serial terminal and communicate with it normally. If I insert the microSD after the OLA is powered on, the card is recognized and I can log data to it normally. It seems only when I try to power it on or wake it from deep sleep when the card is already inserted, that the issue happens.

Things that have been tried:
I've found another post on this forum with pretty much the same issue here:
viewtopic.php?f=172&t=58057

The solution from that post hasn't worked for me. I've tried two different microSD cards, both formatted in FAT32. I've re-formatted both cards and deleting everything on them. I've re-uploaded the firmware to the OLA.

From what I've read elsewhere, it seems most likely to be related to the initial power draw of the microSD. The first card I tried was the one recommended in the SparkFun hookup guide for the OLA. What are the odds that both cards have too high of a power draw, and how would I find that information before purchasing a card? Could it be a problem with the board as well?

Any insight would be appreciated. I'm fairly new to hobby electronics, but I will try to provide any additional information to the best of my ability.

[PaulZC]

Hi,

Apologies for the inconvenience. It does indeed sound like you are having the same SD card power issue as the other forum customer. It's really strange. We've sold thousands of OpenLog Artemis boards, yet this issue has only been reported (twice to my knowledge) on the IMU-less version.

We have seen an issue on the 1GB cards where the contacts may be tarnished, causing connectivity problems. Cleaning them with a little rubbing alcohol solves that issue: viewtopic.php?p=235815#p235815

Please do try a different card if you are able to. If not, you are welcome to return the board.

If you bought the kit directly from SparkFun, you can return it here: https://www.sparkfun.com/returns

If you bought it from a distributor, you will need to return it to them.

Apologies again for the inconvenience.

Best wishes,
Paul

[tdahlstrom]

I would like to post a follow up on this:

I finally managed to get a new OLA shipped from SparkFun, and it's having the exact same issue, again with both microSD cards. I find it unlikely that two consecutive units are faulty in the same way, so there must be something else going on, I just have no idea. Unfortunately, the connector for the lithium battery got stuck in the new unit, and I have pretty well mangled it trying to get it out, so hopefully I haven't damaged the connector on the board, in case this issue can still be resolved.

If anyone has any more advice that would be great, otherwise I may end up switching to a different or simpler data logger.

[PaulZC]

Hi,

Apologies again for the inconvenience. Apologies too that the battery connection was a tight fit.

The 2AH battery should be able to deliver plenty of current - if it is fully charged. Have you tried connecting the battery and USB power and waiting for the battery to charge? The yellow CHG LED will go out when the battery is fully charged. Does that change anything?

Have you tried using a different USB cable? Or, do you have a 5V USB-C charger you could use as the power supply - instead of your computer?

Best wishes,
Paul

[tdahlstrom]

Thanks for the response. I waited until the battery was fully charged and the CHG LED turned off, no change. It works if I insert the SD card while the unit is already powered on, but when I power it down through the serial terminal, it will not power back on. Also tried it with both the battery plugged in and the USB-C connected to a 5V charger - CHG LED comes back on solid, but pressing reset still results in the PWR and STAT LEDs flashing once, then nothing.

I don't immediately have a different a different USB cable available, but I can acquire one and try it again in the morning. Fortunately I was able to get the battery connected out, and though slightly deformed, it can still plug bag in snugly.

[PaulZC]

This really is a puzzle...

Could you please try a test for me? Could you please update the firmware using this specific version (v2.4 "No Power Loss Protection"):

https://github.com/sparkfun/OpenLog_Art ... ection.bin

I'm curious to see if that lets the OLA operate normally, or if it gets stuck in an infinite reset-repeat loop. Please give it a try and report back here.

You can find the full details about the "No Power Loss Protection" version here:

https://github.com/sparkfun/OpenLog_Art ... s/tag/v2.4

Thank you for your support and patience.
Very best wishes,
Paul

[tdahlstrom]

I've uploaded the firmware, and this seems to have fixed the issue. I can insert the SD card, power it down, and successfully power it back on again. It works running off of the lithium battery alone as well. When using the Arduino IDE serial monitor, closing and immediately reopening the monitor after powering down doesn't initiate communication - I have to close the monitor and open it back up again.

I don't know if this is relevant, but it might be interesting - when I open the monitor and begin the communication, the first few characters seem to be completely random, which are followed by "Artemis OpenLog v2.4". It might read something like:

⸮!)⸮KArtemis OpenLog v2.4

And all following lines appear normal. This happened with the previous firmware version as well, and the first few characters are different each time. In any case, I'm curious to hear what the culprit might be in all this. Thank you so much for your help!

[PaulZC]

That's great news. I'm glad the modified firmware is working for you.

The random characters are nothing to worry about. That's just noise on the Serial TX pin as the Artemis comes out of sleep.

I'm beginning to suspect that decoupling - or lack of decoupling capacitance - is the cause here. One way to prove it would be to connect (solder) a 'large' capacitor between the 3V3 and GND breakout pins. 'Large' is something like 22uF, 47uF or 100uF (micro-Farads) with at least a 6V rating. An electrolytic capacitor would be ideal. I don't know if you have the skills and resources to try this, but adding the cap and re-installing the regular v2.4 firmware would be a very useful test. The capacitor will help to deliver the current the microSD card needs at power-on.

Thank you,
Paul

[tdahlstrom]

Paul,

I tried what you suggested and connected a 100uF electrolytic capacitor between 3.3V and GND, and re-uploaded the v2.2 firmware that I originally used. I made sure I could reproduce the problem before connecting the capacitor, which I could, then I connected the capacitor and it started up without any problems. Tried a couple cycles of powering down and starting up again to be sure - looks like that was the issue!

Sorry I didn't to this a bit sooner, but hopefully it's still helpful information. Thanks again for the help!

[PaulZC]

That's great news. Many thanks for the update.

The OLA is a very compact board and there wasn't much room for extra decoupling capacitors. The in-rush current seems to vary from SD card to SD card. It looks like we end up with fringe cases, like yours, where the in-rush causes the power to brown out momentarily. Apologies for your needing to add the extra capacitor - and apologies I didn't think of it sooner.

Very best wishes,
Paul