nRF52840 DK and BME280 with vcc from pin

[404Software]

Hello I use nrf52840 and BME280. I plugged it 
GND GND
SDA 45 (P1.13)
SCL 47 (P1.15)
VCC 32 (P1.00)

I use timer to refresh data and on the first line of the code I init gpio as output I set HIGH state (my voltage meter show me 3V on this pins) and my BME280 I successfully inited (I don't turn off the power on this pin) When I made a measure I receive 50% humidity and 21 temperature which is wrong values. When I connect vcc with vdd on dk board I got correct values. I remove voltage regulator from bme280. Where can be a problem ?

Here is a pin init code 

I use SetGpio to move on on high.

[Håkon Alseth]

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".

 

When I connect vcc with vdd on dk board I got correct values. I remove voltage regulator from bme280. Where can be a problem ?

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

[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 

[Håkon Alseth]

Hi,

 

404Software said:

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 

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

 

Kind regards,

Håkon

[404Software]

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 

[Håkon Alseth]

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