I2C implementation between nrf52832 and cypress capsense button CY8CMBR2110-24LQ.

[techietech]

Hello!!

I want to implement I2C between nrf52832 and capsense button (CY8CMBR2110-24LQ) and want to put it to sleep mode so that I could get ~2-3uA  if there is no activity. Previously, I was using bsp_evt_handler() but wasn't able to achieve low power mode on nrf52832. The capsense is going to be pull up ( default ). 

I would appreciate any soon response. 

1. Capsense I2C lines are connected to  nrf52832 I2C lines.

2. 10 Capsense Buttons are pull up.

3. One Bi-color LED will be there.

4. Need to put in sleep mode for inactivity. 

Thanks

[Edvin]

So what are you observing? Where did it fail? 1: Does it work? 2: Is the current consumption too high?

1: If not, what happens?

2: If so, have you tried measureing the current consumption if you don't enable the button/bsp? Does that give the current consumption you expect? Is the I2C enabled? Is it disabled again?

BR,

Edvin

[techietech]

Hi 

Edvin said:

So what are you observing? Where did it fail?

My code isn't working for low power mode after adding cypress capsense (CY8CMBR2110-24LQ). It fails when it needs to go to System OFF. 1: No 2: Yes ~1.2mA.

1: If you could suggest me any example how to implement I2C and then putting capsense on sleep mode for inactivity.

2. Yes, Nothing changes on current consumption ( ~1.2mA ) for disabling button button/bsp. 

Edvin said:

Does that give the current consumption you expect?

No

Edvin said:

Is the I2C enabled?

I am not using I2C. I have just use bsp_evt_handler.

Thanks

[Edvin]

techietech said:

It fails when it needs to go to System OFF

 In what way? Does the application reset? Or does it enter system off?

 

techietech said:

Yes, Nothing changes on current consumption ( ~1.2mA ) for disabling button button/bsp. 

 So the 1.2mA is what you describe as "not working"? 

Did you at some point have this application running at 2-3µA? What was the thing you added that made the current increase to 1.2mA? 

I am still trying to figure out what the issue is.

[techietech]

Edvin said:

In what way? Does the application reset? Or does it enter system off?

No, application doesn't reset and also enter system off.

Edvin said:

Did you at some point have this application running at 2-3µA?

It was the working before with normal button interrupt and was achieving system OFF current. After replacing the button with capsense I'm not able to achieve system OFF current on inactivity.

If you could provide some example with capsense button implementation with nrf52832 and putting it to sleep mode when there is no activity going on. 

[N Ashelman]

Suggest the SDK power management example as a reference. It shows how to run at low power. Using the techniques in this example you should be able to run at 2~3mA.

If you want to achieve the lowest possible power consumption and your requirements permit it, you should shutdown the nRF completely, so only the CapSense IC is drawing power, Then when a button is pushed, the CY8CMBR2110's "Attention/Sleep line" can be used to boot up the nRF. This should take nRF power consumption to the uA level (but it is not running any code, just waiting to be woken up).