date of production ESP32

davdav
Posts: 89
Joined: Thu Nov 17, 2016 2:33 pm

date of production ESP32

Postby davdav » Thu Mar 01, 2018 1:56 pm

Hi everybody,

I have just discovered that ADC calibration has a step forward for its solution.
Infact, it seems Vref or two point calibration is stored in EFUSE blocks. However this depends on the date of production as stated in documentation.

For example I have some ESP-WROOM-32 modules bought probably one year ago and if I ask the status of EFUSE with

Code: Select all

esp_adc_cal_check_efuse


and they are not supported.
We have also bougth one month ago 100 ESP-WROOM-32 for pre-series of our product and I can't test them because they need to be soldered on PCB.

The question: Which is the starting date of production which guarantees that EFUSE are written with Vref or 2-point calibration? How can I know this on ESP-WROOM-32?


Thanks.

davdav
Posts: 89
Joined: Thu Nov 17, 2016 2:33 pm

Re: date of production ESP32 with ADC calibration included

Postby davdav » Thu Apr 19, 2018 10:26 am

Hi everybody,

Is there any news about the below request?

The espressif sales representive in Italy is not able to know if the ESP32-WROOM modules we are going to buy comprise the EFUSE calibration (Vref, 2 point, ecc.) of ADC. Obviously we cannot mount the modules and discover later that they are not factory calibrated..

Thanks

WiFive
Posts: 1860
Joined: Tue Dec 01, 2015 7:35 am

Re: date of production ESP32

Postby WiFive » Thu Apr 19, 2018 11:50 am

That's why you need one of these: https://www.aliexpress.com/wholesale?ca ... 32+fixture

Personally I would assume that precalibrated devices are special order unless told otherwise.

davdav
Posts: 89
Joined: Thu Nov 17, 2016 2:33 pm

Re: date of production ESP32

Postby davdav » Thu Apr 19, 2018 1:22 pm

Unfortunately this is not an option. If we order a reel of 1000 modules ready for pick and place machine, it is not possible
to test one by one module to check if they have ADC calibration EFUSE. Espressif should assure in some way (marking code on the module for example) that module are already pre-calibrated

And I guess that ADC factory calibration should be the standard since the non-linearity issue of the ADC has been raised by a lot of users.


Thanks

WiFive
Posts: 1860
Joined: Tue Dec 01, 2015 7:35 am

Re: date of production ESP32

Postby WiFive » Fri Apr 20, 2018 12:38 am

Well it would be very strange to have modules in the same reel have some with calibration data and some not so you'd only have to test one.

Unless calibration hardware is fully integrated into 100% production flow it seems like a waste to do it for applications that aren't even going to use adc, which are many. So again I would assume special order and if your sales rep cant tell you how to place such an order I suggest you smack him/her around (verbally) until they do their job and report them to sales@espressif.com if necessary.

davdav
Posts: 89
Joined: Thu Nov 17, 2016 2:33 pm

Re: date of production ESP32

Postby davdav » Sat Apr 21, 2018 3:49 pm

Well it would be very strange to have modules in the same reel have some with calibration data and some not so you'd only have to test one.


That's correct, but we cannot buy a reel and hope that the modules are calibrated. If not, should we put another order and wait for next reel? I guess no...

I'm already in contact with our sales rep. in Italy and also asked support to Brno office. I will look forward for a solution.

Thanks

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