Increasing Coverage of nRF51822 BLE module

[Vaio]

For some sort of geofencing application, we want to include the BLE module nRF51822 into a Base Station (BS), and a small mobile device (MS). The MS should detect the presence of a signal from the BS. If it is/is not present, certain actions are being triggered.

1.) While the maximum TxPower seems to be +4dBm, I heard that using an amplifier one can send up to the regulated limit of +20dBm.

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2.) Alternatively, I heard on the nRF51822 a custom protocol can be implemented. The design goal would be to reach maximum coverage (ideally, beyond walls inside a house).

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For both cases, the same questions arise:

Does anybody have experience / more infos on this? Mainly:

• what is the maximum coverage (in theory and practice)?
• what are the implications on power consumption (as this will be done in the BS, it shouldn't really matter)?

Thanks!

[Håkon Alseth]

Hi,

ESB and GZLL examples can be found in the nRF51 SDK. Note that they are setup with 2Mbit data-rate by default, so you will have to set the desired datarate on both receiver and transmitter.

You're looking into running both BLE and proprietary on one firmware. This is possible (we do it on some of our reference designs, like nRFready Desktop 2.) At this moment, it has it's restrictions. In order to use proprietary communication, you will have to disable the SoftDevice. There's an example in the SDK, called "ble_app_gzll" which switches between gazell and BLE.

For a range test, I would setup a transmitter (based on Enhanced Shockburst example) which sends quickly, let's say every 5 ms. On your receiver, toggle a LED for each 50 packets received.

Note: you will have to set the automatic re-transmit delay to >2700 us for 250kbit on-air mode, as stated here in the documentation: devzone.nordicsemi.com/.../a00896.html

Best regards Håkon

[Håkon Alseth]

forgot to mention; does not matter if it's a devkit or an evkit. Both will do the trick, however the devkit requires that you have nRFgo motherboards. If you do not have/need nRFgo motherboards for nRF24L-series development, I would go for the EVkits.

-H