Transmit Power Configuration

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Last post
Tue, 2020-07-14 07:50
#1
theultimateprasad
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Last seen:9 months 5 days ago
Joined:2020-06-16 20:52
Transmit Power Configuration

Hi I'm using Murata's DA14580 ZY Module for our wearables. So while transmitting/advertising the beacon data and receiving on other ends we are facing some issues like

  • We are not getting the precise RSSI values on 5 to 6 feet distance - its keep on fluctuating
  • Sometimes we can scan the beacons with a distance of 5-6 feet distance, sometimes we are missing it.
  • Frequency interference due to the surrounding 2.4Ghz multiple Wifi Access points.

Pls suggest the solution like Configuration of Transmit power in Software, Configuration of Frequency band switching (priority wise) etc.

Thanks & Regards,

普拉萨德

Device:
DA14580
Tue, 2020-07-14 14:36
PM_Dialog
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Last seen:2 days 14 hours ago
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Joined:2018-02-08 11:03
Hi theultimateprasad,

Hi theultimateprasad,

Thanks for your question online. Can I ask if there any specific reason why you are using DA14580 module in your design?

The DA14580 does have configurable Tx power. According to datasheet :

Supply current at VBAT3V:

  • TX: 3.4 mA, RX: 3.7 mA (with ideal DC-DC)
  • 0 dBm transmit output power
  • -20 dBm output power in “Near Field Mode”
  • -93 dBm receiver sensitivity

If you are starting a new design, we would strongly recommend to start with DA14531 or DA14585/586 products and our latest SDK6.0.14, as it is much more improved. We have a lot of code examples and improved documentation, and there is also software roadmap support. There is no software roadmap support for DA14580 product family and SDK5. Please check out DA14531:

//www.wsdof.com/products/connectivity/bluetooth-low...

The DA14531 has configurable Tx power as well. Please see datasheet :

Radio transceiver

  • Fully integrated 2.4 GHz CMOS Transceiver
  • Single wire antenna
  • TX: 3.5 mA, RX: 2.2 mA (system currents with DC-DC, VBAT_HIGH =3 V and 0 dBm)
  • Programmable transmit output power from -19.5 dBm to +2.5 dBm
  • -94 dBm receiver sensitivity

因为你正在使用一个模块的设计, we also have a DA14531 module, namely DA14531 SmartBond TINY™ Module! It has very small dimensions and is very low power. Follow the link below to find datasheet, documentation and HW collaterals for the module:

//www.wsdof.com/products/bluetooth-module-da14531-s...

Regarding the RSSI, you will not have same accuracy in every distance and always you will have fluctuations. The RSSI is not a fix value. It is the logarithmic value depended on the distance also and the medium between transmitter and receiver. For example noise, dust, and generally environmental conditions will affect the RSSI. Since that is logarithmic from the distance you will notice that small increase of the distance between receiver and transmitter causes a much bigger change on RSSI.

Regarding the Configuration of Frequency band switching (priority wise), could you please clarify it? Since it is a beacon application, please note that the advertising channels are standard. Specifically, a Bluetooth Low Energy device can advertise on channels 37, 38, and 39 which correspond to frequencies of 2.402 MHz, 2.2426 MHz, and 2.480 MHz respectively.

Thanks, PM_Dialog