LoRa WAN development board HTCC AB01 called cube cell from Heltec Automation is a low-power and long-range data communication device. In this documentation, we are going to discuss the power consumption of this cube cell.


 LoRa Communication Spec used for the Low power assessment

 

Parameter

Value

Spread Factor

7

Bandwidth

125 kHz

Preamble

8

Data packet Length

24 bytes

Air Rate Estimate

64 ms approximately

 

 


Hardware Connection

 

Power Profile Kit II

Heltec HTCC-AB01 cubecell board

Vout

3V3(VDD)

GND

GND

 

 

 

                    

fig:Hardware illustration



LoRA Sender and Receiver Firmware

 

We used Heltec Automation’s example code from Git Repo for the power estimation
 
 LoRa Receiver: https://github.com/HelTecAutomation/CubeCell-Arduino/blob/master/libraries/LoRa/examples/LoRaBasic/LoRaReceiver
 LoRa Sender: https://github.com/HelTecAutomation/CubeCell-Arduino/blob/master/libraries/LoRa/examples/LoRaBasic/LoRaSender

 


 POWER CONSUMPTION

 

Power consumption is measured using Nordic Power Profile Kit II (PPK) through nRF Connect for Desktop’s power profile app.Screenshots of the power profile app running on the nRF9160 DK in source meter mode and observed values are shown below.

 

Transmitter

 

Parameter

Value

Vout

3.3 V

Sleep mode

4.5μA

Peak time

100ms

Peak Current

85.55mA

Cycle time

10s

 

 

 

             

 

Fig(a): Low power mode

 

power consumption at low power mode is shown in fig(a) and observed that average power is 4.50μA.

 

                                                  


Fig(b): Peak power estimate

 

power cosumption at the peak is shown in fig(b) and observed that the average power is 85.55mA.

 

                                                    Fig(c): Cycle

 

power consumption of a cycle is shown in fig(c) and observed that the average power is 855.36μA.

 

    Receiver

 

Parameter

Value

Vout

3.3V

Sleep mode

16.99mA

Peak time

242.8ms

Peak Current

20.70mA

Cycle time

10s


 

                                               


Fig(d): Low power mode

 

power consumption at low power mode is shown in fig(d) and observed that the average power is 16.99mA.

 

                                                       

Fig(e): Peak

 

power consumption at the peak is shown in fig(e) and observed that the average power is 20.70mA.

 

                                                        

Fig(f): Cycle

 

The power consumption of a  cycle is shown in fig(f) and observed that the average power is17.08mA.

 

Battey Life calculation



With 10 second cycle, the transmitter can run for almost 4 days with 100mA of Lithium-Ion battery !!

 

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