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    Why a dummy read SPI is required for BMP280?

    Community Manager

    Can you please explain why we need a dummy SPI after switching to SPI protocol? and What is the minimum delay time needed after dummy SPI read?

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    Community Manager

    BMP280 supports both I2C and SPI interface but has no PS (protocol select) pin.

    It starts with the I2C interface enabled. If there is a raising edge on the CSB line, it will switch to the SPI protocol. There should be at least a 140us delay after the first SPI dummy read operation to make sure the bus switch was successful.

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