Adding TWI to ble_app_hrs example

[jeffreyk59]

What is the difference between the twi_sensor example and the twi_master_using_app_twi example? Where do I find any documentation that describes the available functions for each nrf_drv peripheral? Here is what I need to do:

I have 6 TWI slave devices on one TWI bus.  I will need to send initialization data to setup these 6 devices before main loop begins.

In the main loop or in a scheduled app, I will need to periodically read from 4 of these TWI slave devices for:

• battery capacity & voltage
• temperature
• XYZ data from accelerometer
• Status of power switch via On/Off controller

To do this, which example would be best for this application?  The twi_sensor is called each time through the main loop. The twi_master_using_app_twi example appears to setup a scheduled of TWI transactions that occur in a round-robin sort of way.

[jeffreyk59]

Looking at the ble_app_hrs example, it creates and executes four services at various timer intervals:

• Battery Level every 2 seconds
• Heart Rate Measurement every 1 second
• RR interval every 300 ms (I'm not sure what this does)
• Sensor Contact every 5 seconds (I'm not sure what this does either)

In my project, do I need to setup a service for each TWI slave that I want to monitor or using the TWIM can I setup one service that polls each TWI slave (one after the other) every few seconds?

[haakonsh]

Yes, of coarse. 

I suggest you check out examples that uses the Timer library to trigger tasks that are to be executed at regular intervals. Do note that the SoftDevice has execution priority during BLE events. 

See TWI master driver and TWIM driver API docs. 

"In my project, do I need to setup a service for each TWI slave that I want to monitor or using the TWIM can I setup one service that polls each TWI slave (one after the other) every few seconds?" Are you talking about a BLE service or just a regular C routine?