52840 scan mode power consumption

[jdokuen]

some questions for power consumption of 52840. 

We've planned to use about 10 to 30 nRF52840 devices for advertising TX mode. One scan mode device which is connected with our server via LTE have to detect the status of those TX mode devices. TX advertising data will be about 31 byte.  

Can you help me to understand the power consumption of Scan mode device using two of 19A D type batteries. We don't care for TX mode devices' power consumption, however scan mode device's is critical. About it I have few questions like:

1. Which are the most efficient way to use for power consumption :  mesh mode, connection mode or scan mode. 

2. Can you calculate power consumption of scan mode device checking status of TX mode devices which is 10 to 30. It will be used 10 hours a day and during the operation time we have to check the status of TX mode devices through the scan mode device. 

3. Can we make interval of scan mode device? if so how open will be efficient for it? Our TX mode devices will advertise the status 2 times a sec. 

Thank you for your help and time and happy new year~ 

[haakonsh]

For 31 bytes every 500ms, for 10 hours per device the ideal with regards to the power consumption of the receiver is a BLE connection. Though we only support 20 concurrent connections per device, so you will need two Centrals. Power consumption should be approx 300-500µA for each of two devices, having 15 connections each, at 500ms connection intervals. 


You can create your own connection based RF protocol, but that will require significant development time.

BTW: the nRF52832 receiver has a current consumption of ~7mA. Is 7-8mA average current consumption for the scanner okay?

How fast do you need to get the updated device data, what latency is acceptable?
I ask because if you do not actually need updated information two times a second you can duty-cycle the scanner by setting the Scan Window and Scan Interval. A 100ms scan window and 200ms Scan Interval will use the receiver 50% of the time, cutting your power consumption in half, at the cost of missing some of the advertisements.