CC3100MOD: wifi net not found

Hi Vincenzo,

1) Can you provide more details here? Is the issue arising while trying to open the servicepack file with the file system API and write a new copy or with an "Embedded Programming" approach.

2) This is an issue just with these units? Other units placed on the same system appear to be working well?

Thanks,
Ben M

Hi Benjamin,

this issue was raised by me and initially discussed with Vincenzo so let me continue.

1) We use file system API to open and write servicepack file. I tested this problematic unit again by simply writng new file to file syetem and i get an SL_FS_NO_DEVICE_IS_LOADED.

2) There is an issue with these two units on the photo plus 2 units i received this morning from EOL testing. More than hundred units were produced in this batch and all other are working fine.

I do have some R&D samples of our system that have deliberately crippled antenna circuit where i can still get some WiFi networks nearby. With these units i mentioned i am not able to get any WiFi networks at all.

BR,

Primoz

Hi Primoz,

Just a few hints:
- did you inspected solder joins under module by X-ray? Around RF_BG pad are GND pads. Short circuit between RF_BG pad and GND may to create such kind of issue.
- are you able list files in filesystem by Uniflash?
- can you enable transceiver mode from your host and check carrier wave by spectrum analyser? This can give you clue whether RF TX is functional or not.

Error code SL_FS_NO_DEVICE_IS_LOADED (-49) should signalise that serial flash is not properly formatted.

Jan

Hi Jan,

- We are going to inspcect solder joints by X-ray and we'll let you know the results.

- I'll check files with Uniflash. We don't use Uniflash before because NWP module servicepack file is being updated with filesystem API by host MCU.

Is there any particular reason why some CC3100MOD modules don't come with file system formatter properly? As far as i know it there is no Simplelink API for file system format.

We will also check carrier wave with those problematic units.

Best regards,

Primoz

Hi Primoz,

I am not sure what may to happen to not be serial flash properly formatted. From production should be sFlash formatted with uploaded service pack (not guaranteed to be latest version). If you have available UART to your host MCU, you can use this procedure to format sFlash ( processors.wiki.ti.com/.../CC3100_Production_Line_Guide ).

Reason why I asked for list of files from Uniflash is non/existence of file /tmp/phy.cal in flash. Non existence of this file may to signalise some problem with RF calibration after power on.

Jan

Hey Primoz,

Do you have any updates on this?

BR,
Seong

Hi Kim,

see updates below.

Regarding units where servicepack file cannot be updated from host MCU. We used Uniflash tool to list files buf flash was not formatted as Hnz suggested in previous posts. Let me stress that CC3100MOD was brand-new and never used before. We don't like the idea to introduce Uniflash to production EOL and test/format every unit that does not come properly formatted from TI. Is there any way to assure that every module comes properly formatted?

Now about units where no WiFi networks can be found. There were 3 units affected and following tests were done:

Unit #1

• no networks can be found
• files can be listed with Uniflash and file /tmp/phy.cal does exist
• No CW observed with spectrum analyzer

Unit #2

• no networks can be found
• files can be listed with Uniflash and file /tmp/phy.cal does exist
• No CW observed with spectrum analyzer

Unit #3 (most confusing)

• There were no WiFi networks found at EOL but here in the lab i can sometimes list some of networks. 6 or 7 networks can normally be found but with this unit i can randomly find 0 up to 7 networks. Mind that the strongest WiFi network (around -44 dB) can't be alwasy found but others much more weaker can be (arond -80 dB). Cases vice versa where strongest networks can be found but weaker aren't were also observed.
• files can be listed with Uniflash and file /tmp/phy.cal does exist
• No CW observed with spectrum analyzer
• We also tried to connect this unit in AP mode to one of WiFi networks found but connection was never made.

We don't have X-ray results yet but i'll post here once available.

I look forward for suggestions.

BR,

Primoz

Hi Primoz,

Nicely described. Unfortunately I am not able help you more. Please wait for answer from TI.

One comment. Maybe you can try check Ucc of module for a noise. Big noise at Ucc may cause worse RX sensitivity, but I think this is not your case.

Jan

Hi Jan,

we checked Ucc of the module for noise but this is not the case, as you anticipated.

BR,

Primoz

Hi Primoz,

The modules are not formatted during production and the user will need to format them. Unfortunately, the only way to verify this is with Uniflash.

As for the other modules, have they been reflashed and tested again?

BR,
Seong

Hi Kim,

as i can read in CC3100MOD Production Line Guide, All CC3100 modules should come pre-formatted.

We were following this guide when EOL testing had been set-up.

I reflashed (formatted with Uniflash) all the problematic modules and those that didn't come pre-formatted are now working OK.

There was no improvement with those modules where no WiFi networks are found so there must be another issue.

BR,

Primoz

Primoz,

Thanks for the heads up - I've updated the wiki page. Since we've moved this discussion to email with our CQE, I will be closing this thread.

BR,
Seong