I have a motherboard monitoring program on my PC. Along with temperatures, it tells the measured voltages coming out of the power supply.
Here's the question: For the -12v rail, it's hovering around -7 volts and goes as low as -3. For the -5v rail, it's reading -4 volts. Should I consider replacing the power supply? The machine seems to be running fine otherwise.
The difficult we do right away...
...the impossible takes slightly longer.
No no no. Do it while it's running. That makes the measurement at the time there is load on the power supply when the voltages will fluctuate the most. Also, if you pop the connector off the motherboard you have to short the PowerGood line to ground to get the power supply to start.
FYI... if your power was that far off, you'd probably have major problems. Things would flicker on/off or alternatively smoke would start coming out of the power supply or associated regulators (if it was a short causing fluctuations).
I can read /google each one of these devices definitions / description and have some understanding how they work alone.
The question is – how do they fit together?
I have a Arduino Due with “native” USB port.
I can configure the port for USB mouse, keyboard, web cam or flash drive, no problem.
I want to write to flash drive and that is where I am not so sure how USB / SCSI LUN #0 - the only device on the USB bus - interacts with disk / file processing
I got as far as “mounting” drive at LUN #0 , but from there I am lost.
For example I can check if the “drive “ is mounted but the results are intermittent and most of the time the process just stops. And without real debugger, I am stuck. I need to better understand how it all works together to be able to follow the code manually.
Basically – does USB /SCSI LUN #0 id translates into “disk #0 “/ USB device #1? and is there a timing dependency between “working” with file / disk and USB?
Can anybody help me with understanding of how all this hardware / software interacts?
Thanks for your time.
hmm here is the scenario,
in the past months my battery become dead.
Actually I am not sure if its really dead because it say it has 89% of power and charging, but if i pulled out the charger it will turn off. then I tried to insert it to the another laptop, and the same problem occurred. I don't know if it is the battery circuit become faulty.
Then now I have a new battery and it is really good, BUT there is something I noticed, when my processor goes high or my laptop used a lot of resource in the just a matter of time, my power setting changed from charging to not charging and to charging just so quick, i dont know why it is happening, actually I already noticed it before I but a new battery, while running with my dead battery and the adapter.
why it is changing from charging to not charging, if the system used a lot of resource?
what could be the possible cause of it?
EDIT: BTW The charging light indicator of the laptop will blink if this is problem is happening.
The AC adapter provides a specific amount of power. Typical DC output is 19 V with max. 4.74 A (see label on your adapter) which is 90 W. This power is reduced by the efficiency of the internal power supply and battery charging device. Typical efficiencies are 80 to 90%. So you may have about 80 W of useable power from external source. When your system load is high it may require more than these 80 W. Then the additional power is drawn from the battery which is then discharging.
For that reason you should not use the system when charging an empty battery or when the battery level is low. Then the battery is not able to deliver the additional power which will be usually indicated by a low battery indicator.
ohh there is something I notice lately on my laptop,
when it is on high performance power plan it constantly draining the battery even its say it is charging,
then if i switch it in to power saving the power percentage of the battery will become stationary,
then if i will put my to hibernation or turned it off with the adapter it will charged.
could it be my adapter is already been faulty?
ohh by the way I also tried to pull out the battery and switch on my laptop with the adapter, it will just turn on for about a 1 to 2 second then it suddenly lose power and turned off.
Yes, it seems that your AC adapter can not provide enough power. Such adapters should be able to power a laptop without battery including start up where more power is used than during normal operation. Another indication would be long charging times.
I have no idea what happened to your adapter. Such failures are rather seldom. I would guess that a single electronic component is defective or there is a cold solder joint resulting in a lower current limiting.
I am learning all about low level USB devices and would like to develop "stuff" ( term used is "USB controller") to connect Arduino Due "native" port to webcam.
I need to get some idea about how is webcam ( not camera ) hardware implemented.
So far all searches returned "how to connect your web cam to PC".
So there is an optical part ( no tech term yet) and the hardware which "connects" the optics to USB bus, right?
Any info / links etc on HARDWARE will be appreciated, keep in mind this is semi-embedded processor with limited resources - no Windoze API.
Thanks for your time
An USB device typically contains an intelligent controller that understands commands send from the host and prepares data from it's own hardware to be send to the host. So there is some kind of protocol that allows the communication between host and device.
The handling on the host side is done by a device specific driver. This may be a common driver for well known USB device types or a specific one provided by the device manufacturer.
If you want to connect USB devices to your Arduino, you must support the corresponding protocol. I don't have used an Arduino so far, but there should be examples for common devices like storages. For other devices you must write your own protocol implementation using the information provided by the device manufacturer or searching the web (Linux drivers are often a good start).
So you might not need information on hardware but on the protocol used by a specific device.
Jochen, thanks for the info.
Found this link <a href="http://www.usbmadesimple.co.uk/ums_links.htm">http://www.usbmadesimple.co.uk/ums_links.htm</a>[<a href="http://www.usbmadesimple.co.uk/ums_links.htm" target="_blank" title="New Window">^</a>]
Any chance somebody has a code for this display?
I had it working using serial port on AVR (Uno) , but it needs some rebuild to make it work on ARM.
Yes, I did check with the nice folks at Noritake and they don't have much for ARM.
I'll tackle it myself, but I am not that comfortable coding on registers level.
about a year ago i develop a concept of POS system ( it`s demo one ) with a food reservation system also, in details you must provide features of your system you want to determine what hardware you need.