Hello guys, I was looking on google for barometer but I wasn't able to find much. I would be grateful for suggestions, also how are they connected?

Search for “barometer BMP280” should come up with a bunch. It connects to the SDA and CLI pads. There’s also another way to hook up but I’m not familiar with it. Something to do with SPI.

Most old FC's tend to use BMP280 built in which are connected via SPI.

On the other hand, if you were to get an external Barometer then why not try something newer: DSP310.

Compared to BMP280 the DSP310 is claimed to be more precise and is supported by BetaFlight.

The form factor, mounting, soldering/connector options and price of something in the link is a very suitable device for a Brometer on board a quad: https://www.adafruit.com/product/4494#technical-details

Did not know they exist, cool going to have to put one on the chameleon.
Just ordered 2, thanks for the tip.

(30-May-2021, 04:57 PM)Kevin2112 Wrote: Search for “barometer BMP280” should come up with a bunch. It connects to the SDA and CLI pads. There’s also another way to hook up but I’m not familiar with it. Something to do with SPI.

i dont have sda and cli pads, is there other way

(31-May-2021, 07:32 AM)Maiklas Wrote: i dont have sda and cli pads, is there other way

I'm not sure what a CLI pad is, but the baro docs say you can use SPI or I2C (SDA/SCL pads on your FC).

what FC do you have?

Diatone mamba f405 dji

there are I2C SCL & SDA pads on that FC:

https://cdn-unmannedtech.pressidium.com/...0_BL32.jpg

bottom right corner

Mine looks like this https://www.drone-fpv-racer.com/24308-la...roller.jpg

ah, ok. my picture was of a F405DJI F50PRO - looks like you have the regular F405DJI

it seems like you're out of luck with your FC then as it doesn't have I2C - I don't know of any baro that you can connect to a UART

If your FC does not have the SCL/SDA pads broken out then there is not much you can do.

On some FC's the TX/RX pads can be resource mapped as SCL/SDA pads but not all. Usually this is UART 3. But this does not work for all FC's.

(31-May-2021, 11:26 AM)badger Wrote: ah, ok.  my picture was of a F405DJI F50PRO - looks like you have the regular F405DJI

it seems like you're out of luck with your FC then as it doesn't have I2C - I don't know of any baro that you can connect to a UART  

The M8Q-CAN can provide GPS/Baro/Compass data over a single UART via the MSP protocol but Betaflight has not implemented this yet where as ArduPilot and iNav have this implemented.

For that much additional cost, its best to upgrade to an FC that has a Barometer built it or provide SCL/SDA pads.

(31-May-2021, 11:57 AM)kafie1980 Wrote: On some FC's the TX/RX pads can be resource mapped as SCL/SDA pads but not all. Usually this is UART 3. But this does not work for all FC's.

UART1 can also be remapped to an I2C resource but only if the RX pad doesn't have a hardware inverter on it. The Mamba boards have a software enabled inverter so in theory you should be able to disable that that and then use the UART1 pads for as an I2C1 resource. Obviously this can only be done for Betaflight and not INAV.