nRF52840 DK and BME280 with vcc from pin

RE: nRF52840 DK and BME280 with vcc from pin

Håkon Alseth — Tue, 29 Mar 2022 12:30:39 GMT

Hi,

And what were the results between the two implementations?

You mentioned that you got it working with a delay after powering up. Have you checked the datasheet for the sensor, and asked the manufacturer how you should interface the sensor (wrt. to timing) ?

Kind regards,

Håkon

RE: nRF52840 DK and BME280 with vcc from pin

404Software — Tue, 29 Mar 2022 12:04:25 GMT

Yes :)

RE: nRF52840 DK and BME280 with vcc from pin

Håkon Alseth — Wed, 29 Dec 2021 12:07:08 GMT

Have you scoped the VDD + SCL + SDA lines to compare the two examples?

Kind regards,

Håkon

RE: nRF52840 DK and BME280 with vcc from pin

404Software — Wed, 29 Dec 2021 11:21:09 GMT

Yes exactly the same code stopped working on the other sample

RE: nRF52840 DK and BME280 with vcc from pin

Håkon Alseth — Wed, 29 Dec 2021 10:22:17 GMT

Hi,

The same implementation stopped working in the other sample?

Have you scoped the VDD line (and SDA/SCL) to see how it behaves timing wise compared to the working one?

Kind regards,

Håkon

RE: nRF52840 DK and BME280 with vcc from pin

404Software — Tue, 28 Dec 2021 12:36:32 GMT

ok so I use wether example from mfi (nrfConnect ADK) and I got error the same values are still return. When I use example from zephyr with sensor bme280 it works correctly it looks like adk has an mistake

RE: nRF52840 DK and BME280 with vcc from pin

Håkon Alseth — Tue, 28 Dec 2021 12:19:45 GMT

Hi,

[quote user="404Software"]Ok I set 200 ms before measure and it works perfect but on example bme I need to implement it on weather station from MFI there I have problem still measure are the same [/quote]

I am not sure I fully understand the problem. Can't you do the same in your other firmware?

Kind regards,

Håkon

RE: nRF52840 DK and BME280 with vcc from pin

404Software — Tue, 28 Dec 2021 11:52:04 GMT

Ok I set 200 ms before measure and it works perfect but on example bme I need to implement it on weather station from MFI there I have problem still measure are the same

RE: nRF52840 DK and BME280 with vcc from pin

Håkon Alseth — Tue, 28 Dec 2021 11:25:58 GMT

Hi,

If you are to power anything directly from a GPIO, please ensure that the external device isn't exceeding the current consumption that a GPIO can deliver. If you see high ripple, please ensure that the GPIO configuration is in "high drive".

[quote user=""]When I connect vcc with vdd on dk board I got correct values. I remove voltage regulator from bme280. Where can be a problem ?[/quote]

This points towards the voltage on the external sensor needs time to settle. Have you ensured that there is a delay between the voltage rising to a valid level and first sampling? Those parameters can be found in the BME280 datasheet.

Kind regards,

Håkon