External flash for nrf52832

[Prasad]

Hello Everyone!!!

I want to interface an external flash with nrf52832. I will be using it to store the new image downloaded during OTA-DFU. Also, some data will be residing in it. It should be spi or i2c interfaced. Also, I am planning to run my system at around 1.8V.

Can you guys please suggest me any flash satisfying the mention criteria? Do we have a flash driver for it? If not exact, a reference driver to look for?

All suggestions are welcomed.

Regards, Prasad.

[Hung Bui]

We at Nordic don't have a preferred external flash IC to recommend. Any memory chip which support standard I2C and/or SPI should be fine. You can do a quick search.

We also don't have a external flash library for I2C and SPI neither.

However, today we released the nRF52840 (new, more powerful version of nRF52832) which has QSPI and we provided an example of using external memory MX25R6435F. Have a look here.

[Prasad]

Thanks Hung!!!

[joe.ker]

Hi Hung,

I have a custom board based on the nRF52832 and a MX25R1635F external Flash chip. I adapted the QSPI example you mentioned (it uses the standard SPI peripheral) and I can perfectly read back information, like device ID or data from the chip.

I am however unable to write data to SPI flash and I figured that it might be due to the delay between last clock when clocking out data and de-asserting of the chip select signal or other timing related issues. Do you have an idea how to work around that (make CS go high faster) or if it could be another problem?

Many thanks, Josef

[Hung Bui]

Hi Joe.ker, I don't think there is any difference between the MX25R6435F and the MX25R1635F except for the size of the flash. Have you tried to test with our example in the SDK ? Have you made sure to set WREN = true ?

[joe.ker]

Hi Hung, Thanks for looking into it. I just fixed the issue - stupid copy paste mistake of sending the wrong command. It works to rewrite the qspi example so all the same functions are available, but to use a normal spi peripheral instead of qspi (not available on nRF52832) Many thanks, Josef