Profile current draw on Redboard

[aczhang9]

Determine current draw of Redboard while programs are running.

[aczhang9]

Current was measured using multimeter serially connected between DC external power supply and VIN on Redboard.	Program	Max Current Draw Measured
hello_world - 3 LEDs on, loads tflite model and runs inference	7.06mA
micro_speech - 2 LEDs and mic on, loads tflite model, runs inference, cache sleep state enabled	7.50mA
Example1 MicrophoneOutput - 2 LEDs and mic on	8.45mA
micro_speech - 2 LEDs and mic on, loads tflite model, runs inference	9.10mA

[aczhang9]

Data collected from Redboard Artemis running Example 2 Configure Mic (one of the provided examples). The code is also calculating FFTs. Effective sampling rate obtained by changing the clock speed of the PDM, uploading code to board, and verifying the sampling rate and working microphone in the serial monitor of the arduino IDE. Voltage measured in parallel by probing VIN and GND pins of board directly. Current measured in series by powering breadboard with 12V barrel jack. +12V -> red multimeter probe via jumper -> black multimeter probe -> VIN via jumper and then GND to breadboard ground.

Values from AstroAI AM33D multimeter (battery may be running low) Trial	Effective Sampling Rate (kHz)	20mA max current reading (mA)	200mA max current reading (mA)	Voltage In (V)
1	5.859	15.22	6.5	12.01
2	5.859	13.53	6.5	12.15
3	5.859	12.79	6.5	12.27
1	7.812	12.45	6.7	12.27
2	7.812	16.02	6.7	12.12
3	7.812	12.10	6.7	12.16
1	11.718	11.56	7.0	12.16
2	11.718	18.26	7.0	12.10
3	11.718	14.96	7.0	12.13
1	23.437	17.79	7.6	12.10
2	23.437	15.90	7.6	12.28
3	23.437	16.4	7.6	12.13

Average 20mA max current reading: 5.859kHz sampling rate: 13.85mA 7.812kHz sampling rate: 13.52mA 11.718kHz sampling rate: 14.96mA 23.437kHz sampling rate: 16.7mA

[aczhang9]

Values from AstroAI WH500A multimeter using this code example: https://github.com/sparkfun/Arduino_Apollo3/blob/main/libraries/PDM/examples/Example2_ConfigureMic/Example2_ConfigureMic.ino Trial	Effective Sampling Rate (kHz)	max current reading (mA)	Voltage In (V)	Power consumption (mW)
1	0.486	6.37mA	12.29V	78.29
1	0.732	6.40mA	12.29V	78.66
1	0.976	6.45mA	12.29V	79.27
1	1.464	6.53mA	12.29V	80.25
1	1.953	6.59mA	12.29V	80.99
1	2.929	6.67mA	12.29V	81.97
1	3.902	6.72mA	12.29V	82.58
1	5.859	6.76mA	12.29V	83.08
1	11.718	7.26mA	12.29V	89.22
1	15.625	7.34mA	12.29V	90.20
1	23.437	7.87mA	12.29V	96.77
1	46.875	8.65mA	12.29V	106.3

[aczhang9]

Trial	Effective Sampling Rate (kHz)	max current reading (mA)	Voltage In (V)	Power consumption (mW)
1	0.486	6.49	4.83	31.3
1	0.732	6.50	4.90	31.85
1	0.976	6.53	4.93	32.19
1	1.464	6.56	4.93	32.34
1	1.953	6.58	4.93	32.44
1	2.929	6.67	4.93	32.88
1	3.906	6.75	4.90	33.08
1	5.859	6.79	4.91	33.34
1	7.812	6.98	4.87	33.99
1	11.718	7.20	4.88	35.14
1	15.625	7.42	4.88	36.21
1	23.437	7.85	4.88	38.03
1	46.875	8.72	4.83	37.76

Trial	Effective Sampling Rate (kHz)	max current reading (mA)	Voltage In (V)	Power consumption (mW)
1	0.486	4.97	3.26	16.20
1	0.732	4.99	3.26	16.27
1	0.976	5.03	3.27	16.45
1	1.464	5.07	3.26	16.53
1	1.953	5.14	3.26	16.76
1	2.929	5.27	3.26	17.18
1	3.906	5.34	3.26	17.40
1	5.859	5.40	3.26	17.60
1	7.812	5.51	3.26	17.96
1	11.718	5.75	3.26	18.75
1	15.625	5.93	3.26	19.33
1	23.437	6.27	3.26	20.44
1	46.875	7.16	3.26	23.34

Resistance between: GND->3.3V: 31.7kOhms GND->5V: 869Ohms GND->VIN (7-12V): 6.73MOhms