Putting I2C peripheral back into lowest power state

RE: Putting I2C peripheral back into lowest power state

RobMeades — Tue, 28 May 2019 12:13:13 GMT

Hi there. I don't recall having a problem with that but it was some time ago now. All of the code for the project I was doing is public here: https://github.com/u-blox/infinite-iot/tree/master/source so feel free to have a look around to see if I'm doing anything that you are not.

RE: Putting I2C peripheral back into lowest power state

modles — Thu, 23 May 2019 15:27:33 GMT

Hi Rob

Do you have issues with this bringing the I2C back up into a usable state?

Once i run this Errata code i then cannot use my I2C after sleep. any ideas?

Cheers

RE: Putting I2C peripheral back into lowest power state

RobMeades — Fri, 24 Aug 2018 10:08:52 GMT

Yup, that was it, my "switch off" code reduces to:

        NRF_TWIM0->ENABLE = 0;
        *(volatile uint32_t *)0x40003FFC = 0;
        *(volatile uint32_t *)0x40003FFC;
        *(volatile uint32_t *)0x40003FFC = 1;

        NRF_TWIM1->ENABLE = 0;
        *(volatile uint32_t *)0x40004FFC = 0;
        *(volatile uint32_t *)0x40004FFC;
        *(volatile uint32_t *)0x40004FFC = 1;

Many thanks!

RE: Putting I2C peripheral back into lowest power state

RobMeades — Thu, 23 Aug 2018 20:28:03 GMT

Ooo, that looks good, I'll try that and get back to you in the morning.

RE: Putting I2C peripheral back into lowest power state

Jørgen Holmefjord — Thu, 23 Aug 2018 19:26:25 GMT

Hi Rob,

I'm not exactly sure how mbed configures the TWIM peripheral, but normally it should be sufficient to disable the peripheral.

You can try the workaround in Errata 89, which should definitely put the peripheral in the lowest state again.

Best regards.
Jørgen