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

Question

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 · Accepted Answer

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 · Answer

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 · Answer

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.

Edvin · Answer

Edvin said: So try to compare your application before and after you added the capsense buttons. Is your I2C active? Does the current behave like you expect if you never enable I2C? Do you disable the I2C before you go to system off? 
 
 Edvin said: techietech said: No, application doesn't reset and also enter system off. 
 what does that mean? Does the device enter system off or not? 
 You didn't answer any of my previous questions. And now it doesn't answer the TWI calls either? Have you checked the datadsheet for the buttons you are using? Or do you have any drivers? Note that you are not sending the IN_DEEP_SLEEP_VALUE in that call: 
 err_code = nrf_drv_twi_tx(&m_twi, DEFAULT_SLAVE_ADDRESS, register_address, 1, false); 
 Because the length is set to one. You are only sending the first byte.

Edvin · Answer

You need to ask the sensor producers what commands to use to read and write to the values that you are trying to acheive. 
 
 techietech said: No, I am not using I2C but it is connected with pin GPIO 26 & 27. 
 Based on the TWI call it looks like you are using I2C (TWI and I2C is the same).

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

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