The Smart Remote 3 DK add-on has two pin headers available for current measurement. These pin headers make it possible to measure current for the DK add-on and for the microphone.
By default, a 10 Ω resistor (R3) is parallel to P2 and a 0 Ω resistor (R5) is parallel to P9. When performing current measurement, the resistor has to be removed.
There are two ways of measuring the current consumption: using an ampere-meter or an oscilloscope.
With ampere-meter:
- Remove R3 and/or R5
- Connect an ampere-meter between the pins of connector P2 and/or P9. This will monitor the current directly.
With oscilloscope:
- On R3, use the default mounted 10 Ω resistor. On R5, replace the 0 Ω resistor with a resistor not larger than 10 Ω.
- Connect an oscilloscope in differential mode or similar with two probes on the pins of the P2 and/or P9 connectors.
- Measure the voltage drop. The voltage drop will be proportional to the current consumption. For example, if a 10 Ω resistor is chosen, 10 mV equals 1 mA.
Figure 1. DK add-on current measurement
Figure 2. Microphone current measurement
In the figure above, MIC+ refers to the positive side of the microphone.