Solid red on new SD card (DIY)

1

Hi.

I would like to replace the 2gb sdcard inside my Iotawatt (DIY), so I bought an industrial Kingston 8gb sdcit2/8gb.
I copied old files inside and put it in my iotawatt, but not response, except solid red led, no matter what.
I tried with sd card files from github, formatting in fat16/fat32… nothing.
I tried any cheap sd card, and it works.

Is there a compatibility list available?

2

SDHC <= 32GB

Solid red, for a production IotaWatt, would actually be a red glow rather than bright red and would mean that the unit has not connected to WiFi. There is also a condition that I’ve seen where the ESP8266 nodeMCU has an electrical problem and never actually boots up, leaving the led solid red. Since you have a DIY unit, I would suspect the later.

3

Thansk for your quick answer.

Quite right, it’s red glow.

Some SD card always work on this iotawatt unit and other units I have, other SD cards never work on iotawatt units.

I think I found something, I hope.

Here is the tests I made.

  • I put the SD card inside, 19AC on, and I plug micro USB 5V.
    ADATA SDHC I class 1 16gb : red glow.
    ExtremePRO SDHC I class 1 16gb : works.
    SandDisk SDHC I class 1 32gb : works.
    Shandian SDHC I class 1 16gb : red glow.
    OLECO I SDHC class 1 16gb : works.
    Kingston INDUSTRIAL SDHC class 10 8gb : red glow.

  • Now I plug 19AC on, microUSB 5V and quickly insert Sd card
    ADATA SDHC I class 1 16gb : works.
    Shandian SDHC I class 1 16gb : works.
    Kingston INDUSTRIAL SDHC class 10 8gb : works.
    But once I reset the esp8266, red glow, and I have to insert sd card quickly after power on esp8266 to make the unit work again.

What would this trick mean?

4

nothing.

If you are getting a solid (or glowing) red led with no SDcard inserted, the problem is not the SDcard. You should get green-red-red sequence. It is a problem with the PCB. I really can’t help you with that.

1 Like
5

No SD card, I have green-red-red.
With “bad” SD card inserted, I have red glow.
When I insert “bad” SD card right after power the unit on, green blink.

6

You should not be inserting or removing SDcards while the unit is powered up. That can cause all kinds of problems with the card.

Sounds like you have some cards that work. I don’t see any problem here.