nrf52832, SDK v11.0.0, SD 132: How to Keep My Display Rendered and Running After Reset

[Sami]

Hello, I'm currently attempting to display a screen during an OTA-DFU process. First and foremost, through BLE, a BLE Central will command my BLE Peripheral to commence DFU. The Peripheral's application will then display a "do not remove" string on my display, and then the Peripheral will issue a reset in order to transition into the boot loader. However, once the reset is issued, the display will lose its contents and become blank. Looks like the GPIOs (SPI bus) that are controlling the display are wiped away after the reset. 

Is there a way to retain GPIOs in order to keep the string "do not remove" across a reset. I'm currently calling:

  sd_nvic_SystemReset()

to issue the reset. 

Thanks!

[Jared]

Hi

The GPIO state is undefined during a reset, which means that there is no way to retain it's value during one. However, I'm not sure if that is the source of your problem.

• What happens after a reset in your program?
• Does it re-initialize the GPIO pins?
• Does this mean that it clears the display once the program has been reset?
• Should you therefore save your display settings in external memory and reload them after a reset has been performed?
• How is the display powered?

Jared