Difference between revisions of "Hardware: Raspberry Pi"
Lukas Dzunko (talk | contribs) |
Lukas Dzunko (talk | contribs) |
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| + | Just few notes about Raspberry Pi ... | ||
| + | |||
| + | == Power === | ||
| + | According to details from RPi project voltage between 4.75 and 5.25 volts is fine. I personally preffer voltage between 4.80 and 5.00 volts. Voltage below 4.8 volts, can lead to instability of 3v3 regulator (RG2) (e.g. CPU power source) and to connected equipment. Voltage above 5.00 (5.25) can shorten life of board and lead to problems with connected equipment. Voltage above 5.6V trip D17 over voltage protection diode. Make sure that connected USB hub (if any) is not back feeding power. It can cause serious problems as there is no protection on USB output ports. | ||
| + | |||
| + | If you are experiencing random USB device disconnects, repeating keys from keyboard or random reboots (hung) of board then there is something wrong with power source. I think USB charger as source was not so good decision as most of the chargers drop voltage up on power demand. This can lead to under voltage upon power demand which will cause mentioned problems. If you hit some of them, then try to measure voltage between test points or change power source. | ||
| + | |||
| + | My Raspberry Pi is running pretty stable with following power sources: | ||
| + | * [[http://sk.farnell.com/jsp/search/productdetail.jsp?SKU=2254794|RASPBERRY PI PSU]] from Farnell (it is only 1A PSU, so no "hungry" devices. I Have ADATA N005 64GB USB flash disk + receiver for air mouse connected and it is just fine) | ||
| + | * [[http://www.alza.sk/powerocks-stone-3-bila-d338702.htm|Powerocks Stone 3 bílá]] this can act as UPS, but there is still question what is impact of this usage on battery. Only this device provide power at almost exactly 5.00 volts also under load | ||
| + | * [[http://www.alza.sk/gembird-usb-230v-bila-d406953.htm|Gembird]] the name state "Gembird" but it is "energenie". This source is also fine, but without load it is providing approximately 2.50 V which is so close to upper limit. Additionally it is noisy without load. It is working but i don't recommend it. | ||
| + | |||
| + | == Boot configuration == | ||
| + | |||
| + | |||
| + | |||
| + | |||
| + | |||
| + | Voltage between 4.75 and 5.25 volts is fine. | ||
| + | But, below 4.8V, some instability can be expected on 3v3 regulator (RG2). | ||
| + | Don't exceed 5.6V, its trip D17 over voltage protection diode. | ||
| − | |||
Revision as of 21:17, 30 October 2013
Just few notes about Raspberry Pi ...
Power =
According to details from RPi project voltage between 4.75 and 5.25 volts is fine. I personally preffer voltage between 4.80 and 5.00 volts. Voltage below 4.8 volts, can lead to instability of 3v3 regulator (RG2) (e.g. CPU power source) and to connected equipment. Voltage above 5.00 (5.25) can shorten life of board and lead to problems with connected equipment. Voltage above 5.6V trip D17 over voltage protection diode. Make sure that connected USB hub (if any) is not back feeding power. It can cause serious problems as there is no protection on USB output ports.
If you are experiencing random USB device disconnects, repeating keys from keyboard or random reboots (hung) of board then there is something wrong with power source. I think USB charger as source was not so good decision as most of the chargers drop voltage up on power demand. This can lead to under voltage upon power demand which will cause mentioned problems. If you hit some of them, then try to measure voltage between test points or change power source.
My Raspberry Pi is running pretty stable with following power sources:
- [PI PSU] from Farnell (it is only 1A PSU, so no "hungry" devices. I Have ADATA N005 64GB USB flash disk + receiver for air mouse connected and it is just fine)
- [Stone 3 bílá] this can act as UPS, but there is still question what is impact of this usage on battery. Only this device provide power at almost exactly 5.00 volts also under load
- [[1]] the name state "Gembird" but it is "energenie". This source is also fine, but without load it is providing approximately 2.50 V which is so close to upper limit. Additionally it is noisy without load. It is working but i don't recommend it.
Boot configuration
Voltage between 4.75 and 5.25 volts is fine. But, below 4.8V, some instability can be expected on 3v3 regulator (RG2). Don't exceed 5.6V, its trip D17 over voltage protection diode.
pi@raspbmc:~$ cat /boot/config.txt arm_freq=800 force_turbo=1 gpu_mem=128 disable_overscan=1 start_file=start_x.elf fixup_file=fixup_x.dat sdtv_mode=2 hdmi_drive=2 hdmi_group=2 hdmi_mode=39 pi@raspbmc:~$
ro,bg,hard,rsize=32768,wsize=32768,vers=3,tcp
Voltage between 4.75 and 5.25 volts is fine. But, below 4.8V, some instability can be expected on 3v3 regulator (RG2). Don't exceed 5.6V, its trip D17 over voltage protection diode.
