Omega2+ hot hot hot
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@Mark-B said in Omega2+ hot hot hot:
If you have the ability it might be worth measuring current draw and comparing with others. In quick search I found one poster seeing 170 mA. I'll to remember to measure and post mine a bit later.
Just to follow up on this. With my Omega2+ running on a proto-board with nothing but a linear regulator I got the following data points. This is monitoring current with a inexpensive USB voltmeter which has questionable accuracy at low current levels and updates about twice per second.
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idle current ~= 110 mA
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current running cpu intensive task* ~= 170 mA
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current running wifi task** ~= 280 mA average, peaks around 350 mA - board is noticeably warmer to the touch, but not hot
I think this suggests that CPU activity doesn't matter much. If an Omega2 is particularly warm (and not otherwise defective) it's likely because the wifi activity is high for some reason.
* - Python for cpu task gives near 100% cpu
import random
import math
x = 0
for m in range(0,1000000): x = x + math.sin(random.uniform(0.0,1.0))
print(x)** - Python for wifi task run via ssh over wifi gives about 50% cpu load
for k in range(0,10000):
__ for m in range(0,k): print(m,k)Edit to add: I see similar numbers for my Omega 2 (not plus) except "wifi" numbers are higher, with and average of about 330 and peaks up to 420 mA.
Also, the current spikes are apparent in the boot process where the serial debug suggests wifi activity with the first about 20 seconds into boot.
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Hi
My Omega2+ board gets really hot and I see that it consumes around 1.8 Amps continuous current eeven when idle. Just want to know if this behavior is normal?
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1.8A current is not normal.
There may be some type of shortage.
Please use a magnifier to visually check if there are solder bridges/shorts on both sides of the circuit board.ccs_hello
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@ccs-hello -- I have checked and did not find any shortage as far as back of the board is concerned. FYI, I am not using any docks and directly powering the omega2+ from a power supply on VCC and GND pins. Do you think there is some manufacturing defect with the board, please advise
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If you only use two pins (3.3V to Vcc and Gnd to Gnd) and still getting the 1.8A reading, the Omega2 is dead.
Asking for a RMA is the route to take.ccs_hello
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@ccs-hello .. I understand but the board is working fine, I can ssh to it, open is webpage and connect to cloud, only thing is that it consumes 1.8 Amps continuously after switching on. Any comments on that?
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@Akshat-Mehra You have a short somewhere.
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re: still functional but consumes 1.8A
It sounds like driving a car at 60 MPH, while hand-brake pulled and motor oil completely leaked out.ccs_hello
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yes, It may have short somewhere but I can't locate it.
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Something like that can't be a direct short across a power rail, otherwise the system wouldn't be functional.
Instead it would need to be a short between a component and a power rail, a damaged section of a chip, or (part of?) a chip that is habitually operating in latchup, perhaps as a result of previous damage such ESD, overvoltage on the power supply or an I/O, etc.
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@Chris-Stratton Thanks for the explanation. I suspect that it may be an overvoltage on the power supply. If that is the case, then I guess there is no remedy except to throw away the board.. Correct?
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@Akshat-Mehra What are you using for a power supply? Have you verified that the voltage at the Omega power pins is 3.3 V?
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@Mark-B Now, I am using a bench-top power supply and I have checked that it supplies a 3.3 Volts using a DMM. But earlier I used a USB to serial 3V3 FTDI cable to supply power to omega2+ without checking its output. Although it was rated 3V3 but the output was +5V as shown on a DMM, which may have damaged the board.
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It;s live and learn, unfortunately.
These active semiconductor devices cannot tolerate severe over-voltage, even in several seconds range.
It is just that fast, poof (can't hear it and no smoke coming out though) it's a goner.P.S. there is no fuse protection nor Zener diode clamping down the supply voltage thus it's all on the end users' due-diligence.
P.S. 2 I even have a very old $$$$ HP lab bench power supply which will exhibit higher voltage when I power it off. It did cook some of my premium toys (much more than $9 Omega 2+.) I have since added a second power cut-off switch on its output side. Live and learn too,.
ccs_hello
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@Akshat-Mehra Sorry to hear that. I've done similar things an embarrassing number of times, some of them far more visually spectacular.
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Yeah.. Its gone now..
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@Akshat-Mehra said in Omega2+ hot hot hot:
@Mark-B ... earlier I used a USB to serial 3V3 FTDI cable to supply power to omega2+ without checking its output. Although it was rated 3V3 but the output was +5V as shown on a DMM, which may have damaged the board.
Sorry Akshat. For next time, here is a nice $7 American made UART board with 3.3 or 5V switched supply and 3.3V signal lines.
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That board is not good enough.
MCP1703 linear IC regulator 3.3V output's max output current is 250 mA.
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@ccs-hello said in Omega2+ hot hot hot:
That board is not good enough.
MCP1703 linear IC regulator 3.3V output's max output current is 250 mA.Yes, I see now that the MCP1703 is rated to only 250mA. The maker claims his UART supplies up to 400mA at 3.3V. Have one here, I'll run Mark B's wifi load test and get back to you. Might be that this unit is ok for an Omega set-up, but not best for an installation.
