# Autonomous Active Tag Using Energy Harvesting Strategies
## 3 Results
### Complete Tag
#### 3.2.3 Reception Scenario  
In this scenario, the transceiver stays in reception mode and the microcontroller in the active mode for all commands. The current consumption for the transceiver in reception mode is 7.6 mA and for the EEPROM in active mode is 0.99 mA in all cases. The value in the supercapacitor for the measurements is 4.2 V.  
First, the \"read one\" datum from EEPROM, represented in the upper graphic of Figure 9. The time required for the whole operation is approximately 100 milliseconds. The associated energy of this command, since the moment that transceiver changes their mode, is: 12.5 \(\upmu\)J for the EEPROM, 268.8 \(\upmu\)J for the transceiver and 317.9 \(\upmu\)J for the microcontroller; a total of 599.2 \(\upmu\)J.  
Figure 9: Current associated to reception mode at 4.2 V in the supercapacitor for the command read one datum in the upper graphic and read all data in the lower graphic. The transceiver is in reception mode for this test. As in the previous image, the numbers represent which element is the one that has the largest contribution to the consumption of the tag in that interval in each case: 1 is for transceiver, 2 is for the EEPROM and 3 is for the microcontroller. The upper graphic shows the reception of one datum and the confirmation of the transmission, the datum read is the last saved in EEPROM. In the lower graphic, the reception of all possible data and transmission confirmation are shown. The number 2 reflects the EEPROM aggregated consumption and the number 3 is the peak for the transceiver transmission.  
Second, the reception of the \"read all data\" command from EEPROM, as can be seen in the lower graphic of Figure 9. The current consumption is the same as that previously commented for EEPROM, around 0.99 mA, and for the transceiver in every transmission, around 10.6 mA, for the three that this read all data command requires. The time spent in the complete command is around 2.2 s. The associated energy to the command, considering the three packets needed to complete it, are: first transmission: 311.75 \(\upmu\)J for the EEPROM, 2.54 mJ for the transceiver, and 1.37 mJ for the microcontroller; second transmission: 228.7 \(\upmu\)J for the EEPROM, 1.96 mJ for the transceiver, and 1.1 mJ for the microcontroller; third transmission: 0 J for the EEPROM, 0.22 mJ for the transceiver, and 0.3 mJ for the microcontroller. The energy needed between transmissions are 19.79 mJ and 18.22 mJ. The wasted energy for this command is 46.04 mJ.  
Third, \"read date\", Figure 10. The consumption is around 0.99 mA for EEPROM and 10.6 mA for transmission, as in previous commands. The time for this command is around 300 milliseconds. In this case, the associated energy, since the point that the transceiver changes the mode, as in the other commands is: 636.2 \(\upmu\)J for the EEPROM, 623.3 \(\upmu\)J for the transceiver, and 467.7 \(\upmu\)J for the microcontroller; energy of 1.73 mJ in total.  
Finally, the last implemented command is \"write\". The entire process is shown in Figure 11. The total command time is around 157 milliseconds. The associated energy is 567.6 \(\upmu\)J in total, 70.7 \(\upmu\)J for the EEPROM, and 496.9 \(\upmu\)J for the microcontroller.  
Figure 10: Power consumption of the tag after receiving a “read date” command at 4.2 V in the supercapacitor. As in other images, the numbers represent which element is the one that has the largest contribution to the consumption of the tag in that interval in each case: 1 is for the transceiver, 2 is for the EEPROM, and 3 is for the microcontroller. The EEPROM is active longer than in other commands since a concrete date has to be found in the whole memory. After that, the result is sent.