Power Consumption - Scanning and Advertising at same time - S140

[Pegaze]

Hi,

I'm working on a project using BLE via s140, everything works fine until I look more seriously at the current draw of the device.

Simply, my project starts a Scan which lasts X milliseconds and which repeats every 20seconds. In parallel, the device advertises at interval Y milliseconds.

I use Power Profiler in order to obtain average consumption values and here are the results for different configurations.

(Note : Scan_Interval = 100ms and Scan_window = 50ms)

Scan duration  = 1s / Adv Interval = 100ms

So we have:

• Average = 273,31uA
• Scan + Adv = 2,44mA
• Adv = 134,93uA

Scan duration  = 1s / Adv Interval = 3s

So we have:

• Average = 293,99uA
• Scan + Adv = 5,74mA
• Adv = 11,78uA

My question is therefore: why when I increase the advertising interval, during Scan + Advertising, I get a significantly higher consumption ?

thanks for your support

[Simonr]

Hi

Okay, then that makes more sense, as the Coded PHY is expected to draw more power than the Uncoded PHYs (1MBPS/2MBPS). This is mostly because the Coded PHY transmits all packages 8 times to ensure the longer range it provides, and so the central will need to scan for more time as well, so I think this is only expected.

Best regards,

Simon

[Pegaze]

Hi,

I understand, but it makes it very dangerous to use Coded PHY when we want to advertise at the same time.

Let me explain:

When the device advertise, it cuts off the current scan. If we therefore increase the frequency of advertising, we risk breaking the pattern of the Coded PHY. No ?

Best regards,