S120 Scan range is short?

[Wing Cheng]

Hi.

We are doing a few test on the S120 range with the Softdevice v1.0.0. We have a peripheral device that we can scan and connect it with iphone within 50-60m. However when we tried to scan it with our S120 device it only has around 20m range. We have the same hardware on both peripheral and central. So we expect they could go up to 50m if Iphone could scan it in 50-60m. Is there anything we could do in software to increase the scan range?

BR,

Wing

[Asbjørn]

To answer your question first, the only thing you can do in software is to adjust the output power used from the nRF51822. If you are not using +4 dBm already, then you could try adjusting this.

With regard to the range you see there could be a few explanations behind that. I'm not sure what your application looks like and how you are configuring the stack, but to give some examples. It's likely that the iPhone has a better accuracy on its timing than what's available on your nRF51822. 16 MHz accuracy on the nRF51822 is directly related to the carrier accuracy and the 32 kHz is used for stack timing. You might also have a board with a less ideal antenna/design compared to the performance of the iPhone. This might not be that much when you only are using it as a peripheral, but when you use your board as both peripheral and central it could be twice as bad.

If you connect them using both nRF51822 as peripheral and central, can you then keep the link at a longer range than you need to establish the link?