Power measurement with ARM energy probe on Hikey960


#1

Hi,

I have ARM DS-5 Streamline running along with an ARM Energy Probe. I was wondering if the probe can be used with Hikey960 and if so, how? The documentation says there are three current sense resistors R401, R413 and R408(https://github.com/96boards/documentation/blob/master/consumer/hikey/hikey960/hardware-docs/hardware-user-manual.md#power-measurement).

But I don’t see any power measurement headers or IDC pins on the board. How would I go about measuring the power if I had to use the ARM energy probe?

Thanks in advance


#2

They are just resistors I’m afraid so you’ll need to use a probe or clip capable of hanging on to them or, in the case of R401, you can just ignore it completely and measure the voltage and current before the power barrel!


#3

Hi @Nitish_Victor,

Yeah, just as Daniel said, R401/R413/R408 are 0.001Ohm but these is not ideal for measurement.

So e.g. my Hikey960 board is reworked to replace the original 0.001Ohm resistors with below shunt resistors (actually credits to my colleague for beautiful reworking :slight_smile:) :

For the 4.2V VDD voltage domain (R408): 0.33 Ohms
For the 12V DCin voltage domain (R401): 0.1 Ohms
For the 5V SYS voltage domain (R413): 0.82 Ohms

Below is related AEP configure file which I use AEP tool with my Hikey960 board [1] and suggest you could go through the detailed usage for the doc [2]. As Daniel suggested, except these three measurement points, you also could measure energy by using the power jack (and without rework the board).

# arm-probe configuration file                                                                                                      
#                                                                                                                                   
# setup name                                                                                                                        
Hikey960                                                                                                                            
                                                                                                                                    
# <device path>                                                                                                                     
/dev/serial/by-id/usb-NXP_SEMICOND_ARM_Energy_Probe_S_NO00000000-if00                                                               
 DCIN   0.082000        1       -0.014612       0.165300        -0.000231       0.000507        0       Main    VBAT    #ff0000 SoC 
 VDD    0.033000        2       -0.017479       0.167072        -0.000312       0.000983        0       VDD_4V2 DCIN    #ff0000 SoC 
 SYS    0.100000        3       -0.016781       0.162839        -0.000274       0.000776        0       SYS_5V  DCIN    #ff0000 SoC 

[1] https://git.linaro.org/tools/arm-probe.git
[2] https://git.linaro.org/tools/arm-probe.git/tree/arm-energy-probe-101.pdf