READ ME File For Data-set supporting the article entitled "Power Neutral Performance Scaling with Intrinsic MPPT for Energy Harvesting Computing Systems"

Dataset DOI: 10.5258/SOTON/D0679

Readme author: Domenico Balsamo, University of Southampton

This dataset supports the article entitled: "Momentum: Power Neutral Performance Scaling with
Intrinsic MPPT for Energy Harvesting Computing Systems" accepted for publication 
in ACM Transactions on Embedded Computing Systems (TECS'18).

Data Supporting Figures:

Fig. 1: Experimentally obtained power and voltage outputs from a photovoltaic cell and a micro wind
   	turbine. 

Fig. 8: Efficiency of typical LDO and DC-DC regulators [Vout = 2.5V, Iload = 1mA] and PV, and wind
	EH sources [Solar Irradiance = 200W/m2, Wind Speed = 7.4m/s].

Fig. 14:The dependency of Voffset on N, with respect to the solar cell?s MPP curve. 

Fig. 15:Relationship between the Voffset and N, determined by Equation 8 for the PV array from Fig. 14. 

Fig. 16:Relationship between the CPU overhead and Vwidth, determined through simulation using a 24
	hour solar data trace. 

Fig. 18:Experimentally obtained power vs operating point characteristics for both testing platforms for 
	the TI MSP430 MCU and the ODROID XU-4 MP-SoC.

Fig. 21:System performance using a controlled variable voltage supply for the TI MSP430 MCU and
	the ODROID XU-4 MP-SoC.

Fig. 22:Results of available and consumed power over time showing correct power neutral behaviour, for 
	the TI MSP430 MCU and the ODROID XU-4 MP-SoC.

Fig. 23:VC over time whilst testing the system with PV energy harvesting for the TI MSP430 MCU and
	the ODROID XU-4 MP-SoC.

Fig. 24:Power-Voltage characteristics of the system over time, compared with the maximum efficiency point
	curves showing correct MPPT behaviour, for the TI MSP430 MCU and the ODROID XU-4 MP-SoC.

Fig. 25:Demonstration of transient operation on the MSP430 MCU.

Data supporting Tables:

Table 1: Average measured frequency scaling latency on the TI MSP430FR5739 MCU.

Table 2: Average measured frequency scaling latency on the ODROID XU-4 with all CPU cores enabled.

Table 3: Average measured core scaling latency on the ODROID XU-4 operating at 0.2 GHz.

Table 4: Efficiency comparisons against hardware MPPT.

Table 5: Forward application execution when using Momentum, compared against existing approaches,
         for the MCU.

Table 6: Forward application execution when using Momentum, compared with the state-of-art for the MP-SoC.


Related Projects:
+++++++++++++++++
Al-Hashimi, B. & Merrett, G., Continuous on-line adaptation in many-core systems: From graceful degradation to graceful amelioration, EPSRC, EP/L000563/1

Reeve, J., Butler, M., Al-Hashimi, B. & Merrett, G., PRiME: Power-efficient, Reliable, Many-Core Embedded systems, EPSRC, EP/K034448/1


Dataset available under a CC BY 4.0 licence

Publisher: University of Southampton, U.K.

Date: October 2018