8.1 Example Calculations

This section helps the user in estimating the average power consumption for the sleeping device in their network. This scenario includes an actual measurement to understand the deviation between the estimated and measured value. The user can do this by determining the typical events that the node can encounter in its lifetime and estimating the power consumed based on the power consumption measurements done in this application note.

The following example scenario explains the steps involved in estimating the average power consumption for a sleeping device node in a Mi-Wi Star topology:

Sleeping device initializes and sends a P2P connection request and scans for a connection response
Sleeping device sends an indirect data request every 120 seconds
Sleeping device sends a link status every 120 seconds
Sleeping device sends application data every 120 seconds

The following example estimates the power consumption for a one-hour duration. Within this duration, the sleeping device completes the connection to the nearby P2P device, 60 data requests and 30 link status. The following table helps in estimating the average power consumption for the device in the chosen measurement duration.

Table 8-1. Measurement Duration
Total measurement duration (ms)	3600000

Table 8-2. SAM R30 XPro
Scenario	Estimated Number of Instances	Single Instance Duration (ms)	Measured Total Duration (ms)	Measured Average Current (mA)	Estimated Average Charge Consumed (mA*ms)
Initialization	1	153.14	153.14	1.74	266.4636
P2P connection request and response	1	28.8	28.8	12.34	355.392
Scan duration	1	1959	1959	10.45	20471.55
App data	30	140	4200	11.16	46872
Periodic indirect data request	30	50.9	1527	9.02	13773.54
Periodic indirect data request with link status	30	60.7	1821	9.76	17772.96
Estimated total charge consumption (excluding Sleep)	—	—	—	—	99511.9056

Table 8-3. SAM R30 Module XPro
Scenario	Estimated Number of Instances	Single Instance Duration (ms)	Measured Total Duration (ms)	Measured Average Current (mA)	Estimated Average Charge Consumed (mA*ms)
Initialization	1	125.6	125.6	1.73	217.288
P2P connection request and response	1	31	31	12.8	396.8
Scan duration	1	1935	1935	10.55	20414.25
App data	30	12	360	12	4320
Periodic indirect data request	30	50.9	1527	9.981	15240.987
Periodic indirect data request with link status	30	60.5	1815	11.1	20146
Estimated total charge consumption (excluding Sleep)	—	—	5668	—	60518.537

Table 8-4. Estimated Charge Consumption Calculations for Sleep
Parameters	SAM R30 XPro	SAM R30 Module XPro
Measured sleep current (mA)	0.00186	0.00176
Estimated total sleep duration (ms) (Total measurement duration - Sum of measured total duration)	3590311.06	3594332
Estimated total sleep charge consumption (mA*ms)	6677.978572	6326.02432

Table 8-5. Estimated Total Charge and Current Consumption
Parameters	SAM R30 XPro	SAM R30 Module XPro
Estimated total charge consumption (including Sleep)	106189.8842	66844.56132
Estimated total average current consumption (mA)	0.02949719	0.018567934

The following example scenario explains the steps involved in estimating and measuring the average power consumption for a sleeping device node in a Mi-Wi Star topology:

Sleeping device initializes and sends the P2P connection request and scans for the connection response
Sleeping device sends the indirect data request every 8 seconds
Sleeping device sends the link status every 15 seconds

The following example uses an arbitrary measurement duration of 17.152 seconds and, within this duration, the sleeping device would have completed the connection to the nearby P2P device and one indirect data request with link status. The following table helps in estimating the average power consumption for the device in the chosen measurement duration:

Table 8-6. Measurement Duration
Total measurement duration (ms)	17152

The following are the estimated charge consumption calculations for scenarios except sleep.

Table 8-7. SAM R30 XPro
Scenario	Estimated Number of Instances	Single Instance Duration (ms)	Measured Total Duration (ms)	Measured Average Current (mA)	Estimated Average Charge Consumed (mA*ms)
Initialization	1	153.14	153.14	1.74	266.4636
P2P connection request and response	1	28.8	28.8	12.34	355.392
Scan duration	1	1959	1959	10.45	20471.55
Periodic indirect data request	1	50.9	50.9	9.02	459.118
Periodic indirect data request with link status	1	60.7	60.7	9.76	592.432
Estimated total charge consumption (excluding Sleep)	—	—	—	—	22144.9556

Table 8-8. SAM R30 Module XPro
Scenario	Estimated Number of Instances	Single Instance Duration (ms)	Measured Total Duration (ms)	Measured Average Current (mA)	Estimated Average Charge Consumed (mA*ms)
Initialization	1	125.6	125.6	1.73	217.288
P2P connection request and response	1	31	31	12.8	396.8
Scan duration	1	1935	1935	10.55	20414.25
Periodic indirect data request	1	9.02	9.02	50.9	459.118
Periodic indirect data request with link status	1	9.76	9.76	60.5	590.48
Estimated total charge consumption (excluding Sleep)	—	2110.38	—	—	22077.936

Table 8-9. Estimated Charge Consumption Calculations for Sleep
Parameters	SAM R30 XPro	SAM R30 Module XPro
Measured Sleep current (mA)	0.00186	0.00176
Estimated total Sleep duration (ms) (Total measurement duration – Sum of measured total duration)	14899.46	15041.62
Estimated total Sleep charge consumption (mA*ms)	27.7129956	26.4732512

Table 8-10. Estimated Total Charge and Current Consumption
Parameters	SAM R30 XPro	SAM R30 Module XPro
Estimated total charge consumption (including Sleep)	22172.6686	22104.409251
Estimated total average current consumption (mA)	1.292716219	1.2887365468

Table 8-11. Measured Current Consumption
Parameters	SAM R30 XPro	SAM R30 Module XPro
Measured total average current consumption (mA)	1.23	1.24

When the total duration increases, the maximum component of current consumption can only be Sleep, which would result in a lower average current consumption as such.