C-4 weird Temperature Reading

Using URL /hub/advanced/internalTempCelsius to read my C-4 temp, range is 70 C -86 C, but sometimes get -1 C. Wondering if the temp reading and processing is out of scope :innocent:

I use infrared thermo to test surface of the box is around 31 c, C-5 is around 29(http read 39 C ). Why C-4's temperature is so high via http call? I touch the box, it is a little bit warmer than C-5. I don't think over 80 c is correct, comapre to my RPi4 box, pretty warm than C-4, but CPU is around 45-49 C.

The reason I am looking at C-4 is my C-4 receives severeLoad every 3-4 days and have to reboot. I am wondering if the reason is the temperature as my device load (0.7%) and App load (1-1.5%) are pretty low. I need to find the root cause of it..


Here's a driver you need to read the hub temp. My C3 is around 54C and around 49C with an external cooling fan.

Yes, I am using Hub info driver to get hub temp sometimes showing as -1 C. I am wondering my C-4 is too hot


From what I’ve read the reading is coming directly from the cpu, but -1 sounds like a register overflow. Assuming a signed byte that would mean a temperature in excess of 128°C.

I get periodic -1s on both my C-4s. I think it is a 'feature'. I just filter them out of my grafana/node-red graphs.

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regardless -1 c, my c-4's temp is still too high.. I'm wondering sth wrong internally, unless temp is not accurate for c-4 as it is not hot at all, just a little bit warm,, over 80 C definitely not hand touched warm..

I get the same, both in terms of the -1's and the high temps. I have both a C-4 and C-7, C-4 ranges from 69C - 80+C. I currently have a pedestal fan providing some temperature control.... Not sure what I will put in place long term, if anything. Like you it doesn't feel any hotter to the touch than my C-7 that is typically around the mid 30's.

And here I am worry about 54C :exploding_head:. I use this fan to bring my temp below 50.


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Both my C-4 hubs AVERAGE 70-75C, with spikes higher regularly. Work fine, and have for 18 months.

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Interestingly there have been other reports of the Amlogic S905X (close relative of the S905W used by C3/C4) occasionally reporting anomalous temp readings: Thermal reading wrong - #7 by Gouwa - Technical Support - Khadas Community
Consensus seems to be that they can be ignored.

My C3 usually reports temps in the mid 50's to mid 60's °C with ambient around 65F. The datasheet for the S905 (I haven't found one for the S905W, but it's also on a 28nm node) shows absolute max Tj of 125 °C; junction temp of an on-chip thermal diode (not case internal ambient) is most likely what is being reported by HE's temperature URL.

The S905's datasheet's recommended max operating ambient of 70°C comes with the caveat "For operating temperature, good heat sink may be needed to guarantee Tj < 125°C". That spec maybe a tad optimistic given a few benchmarking reports of S905-based Android TV boxes locking up when reaching 115°C while running AnTuTu, but junction temps in the 50-90C range don't seem to be out of the ordinary.