My goal is to use the Power Profiler Kit II (PPK2) to measure the energy consumption of an ESP32-H2 under deep sleep, when it is running the boilerplate OpenThread deep sleep program given by Espressif (the manufacturer of the ESP32-H2). However, in order to double check that my PPK2 is actually getting the correct current measurements of ~ 7 uA at deep sleep (as stated by Espressif), I am currently trying to use the Analog Discovery 3 to measure the current of my ESP32-H2 under deep sleep. The reason I am doing so is because an engineer at Nordic Semiconductors (the manufacturer of the PPK2) recommended me to use an external measurement device if I think that the PPK2 is giving me inaccurate measurements.
Since the Digilent Analog Discovery 3 cannot measure current directly, I created the circuit shown below, with a 1 Ω resistor.
A picture the circuit that I built can be seen in the images below:
I used the "Scope mode" of the Digilent Waveforms application. I used a math function to subtract the measured voltages between Channels 1 and 2 to obtain the voltage drop, and then I converted that voltage drop into current, measured in mA.
I then compared the measurements I got from the Analog Discovery 3 with what I got when the PPK2. When using the PPK2, I used its own power supply, rather than the supply of the Discovery 3.
When using the Analog Discovery 3 there are two issues I noticed. First the PPK2 is able to measure the deep sleep current at close to ~7.5-8 uA:
but the deep sleep current measurements Analog Discovery 3 seem to be a bit noisy:
When it comes to the current measurements on wakeup, the Analog Discovery 3 gives the same waveform shapes as the PPK2, but the maximum currents are different.
In the PPK2, the maximum current never reaches greater than 140 mA:
But the Digilent Analog Discovery gives larger currents as large as 150 mA on wakeup:
Furthermore, as can be seen above, the waveforms in the Analog Discovery 3 seem to be less detailed than the ones offered by the PPK2. I also tried modifying the circuit by using a 0.1 Ω resistor resistor, but I still get the same deep sleep measurements that I got in the screenshots above (i.e. when using the 1 Ω resistor).
Given that my results from the PPK2 more closely match the expected ~7 uA deep sleep than the Analog Discovery, I could just say that the PPK2 is accurate and my circuit setup is incorrect. However, I can't make this conclusion from the results of the Analog Discovery 3, as it doesn't tell me whether the problem is coming from my circuit setup or the PPK2. As a result, in order to truly confirm that the PPK2 readings are inaccurate, my goal is to set up the circuit with the Analog Discovery to see if it possible to obtain the same results as the PPK2.
At a higher level, I suspect that there might be something I am doing wrong with my setup when measuring deep sleep, and I'm trying to confirm whether the source of the problem is the potential measurement inaccuracies with the PPK2, or how I configured my ESP32-H2 microcontroller. Assuming I am using the Analog Discovery 3 correctly, I can use its measurements to determine where the source of the problem is coming from.
As a result, I would like to ask what am I doing wrong, with respect to my circuit setup and how I use the Analog Discovery 3, that is causing me to have measurements that are inconsistent with the PPK2 and the measurements given by Espressif? Any feedback and guidance that can help me in the right direction would greatly be appreciated.
Edited by siatran Mentioned that I used PPK2 power supply when using PPK2.
Question
siatran
Hello everyone,
My goal is to use the Power Profiler Kit II (PPK2) to measure the energy consumption of an ESP32-H2 under deep sleep, when it is running the boilerplate OpenThread deep sleep program given by Espressif (the manufacturer of the ESP32-H2). However, in order to double check that my PPK2 is actually getting the correct current measurements of ~ 7 uA at deep sleep (as stated by Espressif), I am currently trying to use the Analog Discovery 3 to measure the current of my ESP32-H2 under deep sleep. The reason I am doing so is because an engineer at Nordic Semiconductors (the manufacturer of the PPK2) recommended me to use an external measurement device if I think that the PPK2 is giving me inaccurate measurements.
Since the Digilent Analog Discovery 3 cannot measure current directly, I created the circuit shown below, with a 1 Ω resistor.
A picture the circuit that I built can be seen in the images below:
I used the "Scope mode" of the Digilent Waveforms application. I used a math function to subtract the measured voltages between Channels 1 and 2 to obtain the voltage drop, and then I converted that voltage drop into current, measured in mA.
I then compared the measurements I got from the Analog Discovery 3 with what I got when the PPK2. When using the PPK2, I used its own power supply, rather than the supply of the Discovery 3.
When using the Analog Discovery 3 there are two issues I noticed. First the PPK2 is able to measure the deep sleep current at close to ~7.5-8 uA:
but the deep sleep current measurements Analog Discovery 3 seem to be a bit noisy:
When it comes to the current measurements on wakeup, the Analog Discovery 3 gives the same waveform shapes as the PPK2, but the maximum currents are different.
In the PPK2, the maximum current never reaches greater than 140 mA:
But the Digilent Analog Discovery gives larger currents as large as 150 mA on wakeup:
Furthermore, as can be seen above, the waveforms in the Analog Discovery 3 seem to be less detailed than the ones offered by the PPK2. I also tried modifying the circuit by using a 0.1 Ω resistor resistor, but I still get the same deep sleep measurements that I got in the screenshots above (i.e. when using the 1 Ω resistor).
Given that my results from the PPK2 more closely match the expected ~7 uA deep sleep than the Analog Discovery, I could just say that the PPK2 is accurate and my circuit setup is incorrect. However, I can't make this conclusion from the results of the Analog Discovery 3, as it doesn't tell me whether the problem is coming from my circuit setup or the PPK2. As a result, in order to truly confirm that the PPK2 readings are inaccurate, my goal is to set up the circuit with the Analog Discovery to see if it possible to obtain the same results as the PPK2.
At a higher level, I suspect that there might be something I am doing wrong with my setup when measuring deep sleep, and I'm trying to confirm whether the source of the problem is the potential measurement inaccuracies with the PPK2, or how I configured my ESP32-H2 microcontroller. Assuming I am using the Analog Discovery 3 correctly, I can use its measurements to determine where the source of the problem is coming from.
As a result, I would like to ask what am I doing wrong, with respect to my circuit setup and how I use the Analog Discovery 3, that is causing me to have measurements that are inconsistent with the PPK2 and the measurements given by Espressif? Any feedback and guidance that can help me in the right direction would greatly be appreciated.
Edited by siatranMentioned that I used PPK2 power supply when using PPK2.
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