S112/S113 is currently the only supported SoftDevice on nRF52805 and doesn't support Central (Only Peripheral). Is there a plan to enable S132, SoftDevice Central are suited for end products.? If yes by when can we expect?
We want to build a such small simple device with few functions, but with central role (bassically a button over BLE, battery powered)
Could you elaborate why you want / need such a simple device to have the central role? Could you not achieve this functionality through a device in a peripheral role?
We want to build a such small simple device with few functions, but with central role (bassically a button over BLE, battery powered)
Could you elaborate why you want / need such a simple device to have the central role? Could you not achieve this functionality through a device in a peripheral role?
The BLE button will send infrormation to a BLE relay which is peripheral.
The BLE button I think it will save more power if it is central and sends data over BLE only when the buton is pushed ; this way also the response time is shorter. comparing to the case when the buton is peripheral
The BLE button I think it will save more power if it is central and sends data over BLE only when the buton is pushed ;
No, I do not think that this is correct. This would mean that you would wake up the device when the button is pressed to start scanning, and you would have to scan until you found the advertisements of the peripheral device. Scanning has a higher power consumption than advertising since scanning uses the radio continuously during the scanning window, compared to advertisements which is contained to a short period. If the central does not immediately find the peripheral device it might go on to scan for a relatively long time (active radio time compared to advertising), which will consume more power. If you instead wake the device to do spaced out advertising upon the button press (or starting out with fast advertisings, then moving to spaced out ones) should give you a lower over all power consumption.
fionut said:
this way also the response time is shorter. comparing to the case when the buton is peripheral
The timing difference between the peripheral's first reception of a central data payload packet and the central's first reception of a peripheral data payload packet is neglectable - it depends on the connection configuration, but it will be in the 100 of µs range. Additionally, the SoftDevice will not give back control of the CPU to the application before it is finished with the entire exchange, which is why I would call this difference in first data packet reception time neglectable.
You could take a look at how the different parameters and exchanges will look in the Online Power Profiler.
