getting RSSI by serial communication using nrf51822

RE: getting RSSI by serial communication using nrf51822

Anders Strand — Wed, 16 Sep 2015 06:50:00 GMT

Many of our examples use the UART, for example the heart rate collector project. You can also check out the pure uart example. Check also out this basic tutorial.

RE: getting RSSI by serial communication using nrf51822

Ramin — Fri, 11 Sep 2015 15:47:09 GMT

Thanks again. I read almost all of tutorial about three weeks ago, but I didnt find scanning code there. but the code snippets will be useful. What about the serial connection? how can I pass p_ble_evt->evt.gap_evt.params.adv_report.rssi by UART?

RE: getting RSSI by serial communication using nrf51822

Anders Strand — Fri, 11 Sep 2015 14:11:08 GMT

You can still use the same method i described. I updated my answer with more information.

RE: getting RSSI by serial communication using nrf51822

Ramin — Fri, 11 Sep 2015 13:28:16 GMT

Thank You for ur answer. I think you didn't get exactly my question (or I didnt get ur answer correctly). Assume that I have two nrf51822 dongle and I want to read RSSI values of one peripheral device(which send the advertising packets). I am not very expert in programming dongle. Is there any code doing exactly what I want or at least a same example code? I used the program that MCP can upload on dongle (I think it is using s110 soft device). For serial communication how can I use UART?

RE: getting RSSI by serial communication using nrf51822

Anders Strand — Fri, 11 Sep 2015 12:48:31 GMT

Hey.

If you flash your nrf51 with softdevice S120 or S130, you can act as a BLE central device. You can base your code on one of our example projects, for example this one.

From there you have two options:

Advertise with your two sensors periodically, and scan them with the S120. Then extract the RSSI from the advertising packets.
Connect to both sensors, and read their RSSI from the data packets received.

The first options is easiest to implement, but the last option is more power efficient. In addition, option 2 will allow for encryption of the data.

When the BLE part of your application is sorted, you simply communicate with your PC using UART.

EDIT1: Briefly how to use the S120/S130 for scanning after RSSI values

Start scanning
Handle the "BLE_GAP_EVT_ADV_REPORT"-event in the on_ble_evt() function. This is where the advertisement packets from the scanner is coming in. Find your devices in the advertisement report using either the name, UUID or address. Use the adv_report_parse() function to extract various data from the advertisement packet.
Read out the rssi from the p_ble_evt->evt.gap_evt.params.adv_report.rssi value.

Take a look at this devzone case for some code snippets.

If you are just starting out with programming of the nRF chip, this might be a small hurdle to get over. I advice you to read the tutorials here on devzone, as well as search here for any problems you encounter.