lower power consumption ant and ble

[Matthias]

Hello,

i have an application that sends periodically sensor data from one sensor network (6 sensors - 16 Bytes) to a host f = 1/4 - 20 Hz. I read the s210 and s110 SDS but in 210 on page 40 the diagram says at the x-axis "Sample Num(50 kHz rate)" Could you please tell me what time base that is? Or how long it tkaes to send 16 Bytes over Ant and how much energy it approximately takes?

Thank you a lot! Matthias

[Stefan Birnir Sverrisson]

Hi Matthias

Thank you for your observation.

The x-axis label and scale in figure 12 of S210 Softdevice Specification v2.0 does not make sense to me either. I know for a fact that from the beginning of (A) until beginning of (D) is 1.5ms. So if we replace the x-axis values in the following way:

50 with 1 ms
100 with 2 ms
150 with 3 ms
...

then it seems to be more or less correct. I have reported this as a documentation error.

[Matthias]

Thank you a lot! Well, somehow it works with that axis description: If you do it like x/50k you get for 150 the 3 ms, but i wasnt sure i i did it right that way. now i'm sure and can continue working.

[Matthias]

the shown profile is for ANT acknowledged broadcast with 8 bytes, is that correct? I'm trying to find out if the data transmittion is lower energy with ANT or BLE (i have 16 bytes to transmit) until now, everything speaks for BLE with only 3,5 ms.

[Matthias]

Hi Matthias. If you are transmitting 16 bytes, I would think BLE is the winner in terms of current consumption, simply because it can put that data into one packet while ANT needs to put that into 2 packets. When transmitting 2 packets, the connection event lasts much longer and you need to keep the 16MHz crystal enabled or in standby during the whole connection event which consumes a lot of current. Furthermore, for ANT you need to enable the radio in RX two times because you send two packets, instead of once when using BLE.