Saving Data to NRF52840 then Writing to SD card.

[wellmacj]

Hello,

I have an NRF52840 and I was wondering if I wanted to save IMU data to storage on the microcontroller, would that be better on flash or eeprom, as from what i know those are the two main types of storage on the microcontroller. With my project, directly writing to the SD would take too much energy and I would like to save accelerometer and gyroscope data to the microcontroller then move it to the SD card when absolutely necessary. If anyone had any insight to help that would be awesome.

microcontroller: Seeed XIAO nrf52840 Sense

IDE : Arduino

[Turbo J]

The program flash inside the NRF5280 does not like to be written to too often, much less than an SD card.

Try buffering a decent amount of data in RAM, then write to card.

Warning: When you write 16KB at once to the card, it may not turn back to low power mode on its own. Reading or writing a single sector fixes that behavior IIRC.

[wellmacj]

got it i'll check out buffering the data in the RAM, and also focus on writing in smaller amounts less than 16 KB. got it. Thank you for the response.

[Vidar Berg]

I agree with what Turbo J  said above. I have not profiled the current consumption of writing to internal flash vs. writing to an SD card, but I assume it should be efficient to store it to a SD card as well. 

For reference, the internal flash is rated to last 10 000 write/erase cycles, see Absolute maximum ratings. This applies to each 4K flash page.