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by nutron
Tue Aug 04, 2020 1:26 am
Forum: General discussion
Topic: Pi4 EEPROM not recoverable / bricked
Replies: 18
Views: 701

Re: Pi4 EEPROM not recoverable / bricked

@ cleverca22: I tried that on a windows machine. no ding at all , not even a unrecognized device or device failed message. i guess the CPU is dead in some way. it was worth trying though and very educational. i guess we all learned a little today , which certainly is the raspberry pi spirit. If anyb...
by nutron
Mon Aug 03, 2020 6:47 pm
Forum: General discussion
Topic: Pi4 EEPROM not recoverable / bricked
Replies: 18
Views: 701

Re: Pi4 EEPROM not recoverable / bricked

@trejan:

Are you sure the switch is not used ?
One of the pins is connected to a resistor i believe.
by nutron
Mon Aug 03, 2020 5:18 pm
Forum: General discussion
Topic: Pi4 EEPROM not recoverable / bricked
Replies: 18
Views: 701

Re: Pi4 EEPROM not recoverable / bricked

@ Herbaldew i tried several sd cards , still the same. @ timg236 Good to know about the UART and the ACT LED during recovery. is the "4H9320G165L" the boot EEPROM ? (see image in original post) Inside the SD card slot , there is a switch. Is that switch important for SOC to detect weather there is a...
by nutron
Mon Aug 03, 2020 3:33 pm
Forum: General discussion
Topic: Pi4 EEPROM not recoverable / bricked
Replies: 18
Views: 701

Re: Pi4 EEPROM not recoverable / bricked

So i hooked up the PI to a scope and observed the UART TX pin at power up. All i got was a small pulse. what i said earlier about the PI answering back , it was probably some noise being reflected back on the UART. scope.jpg Here is what the sd card looks like. I used the RPI imager program to creat...
by nutron
Mon Aug 03, 2020 1:37 pm
Forum: General discussion
Topic: Pi4 EEPROM not recoverable / bricked
Replies: 18
Views: 701

Re: Pi4 EEPROM not recoverable / bricked

@ cleberca22: -I have no other RPI4 to test it on. -inserted the recovery sd card and shorted RUN and GND , no ACT LED flash. -adding "uart_2ndstage=1" to raspbian config.txt didn't do anything either. -voltages on rails are all OK. @trejan: Thanks for part number. How did you know what the part num...
by nutron
Mon Aug 03, 2020 1:09 pm
Forum: General discussion
Topic: Pi4 EEPROM not recoverable / bricked
Replies: 18
Views: 701

Re: Pi4 EEPROM not recoverable / bricked

UART is not completely dead. When i use a serial bus analyzer and type in random characters , it responds somewhat. for example , if i send out 0x02 0x41 0x42 0x43 0x04 (start of text ,A,B,C, end of transmission) , i get back "@, NULL , ! NULL , end of transmission ,NULL" back (0x40 0x00 0x21 0x00 0...
by nutron
Mon Aug 03, 2020 12:42 pm
Forum: General discussion
Topic: Pi4 EEPROM not recoverable / bricked
Replies: 18
Views: 701

Re: Pi4 EEPROM not recoverable / bricked

I tried that too , nothing.

Had UART baudrate at 115200. Connected USB to UART cable to GPIO14 and 15.
by nutron
Mon Aug 03, 2020 12:28 pm
Forum: General discussion
Topic: Pi4 EEPROM not recoverable / bricked
Replies: 18
Views: 701

Pi4 EEPROM not recoverable / bricked

so , i have one of those Pi4 model-Bs where it is not possible to restore the EEPROM with the suggested recovery method(s)... -Used a 4GB micro sd , formatted to FAT and FAT32 , copied recovery files to it and power cycled. -Used 4GB micro sd , used RPI imager and selected recovery image option. The...
by nutron
Wed Aug 28, 2019 9:02 pm
Forum: Camera board
Topic: Picamera graphic overlay update function = 100% CPU load
Replies: 0
Views: 475

Picamera graphic overlay update function = 100% CPU load

I noticed that using the update function of the overlay renderer of Picamera causes the CPU to run at 100% load and stay there until the renderer has been removed. pseudo code... ..... img1 = Image.new("RGBA", (1280, 720),(255,255,255,0)) img1= Image.open("overlay1.png") .... overlay_renderer1 = cam...
by nutron
Wed Aug 28, 2019 8:46 pm
Forum: Camera board
Topic: Official V4L2 driver
Replies: 561
Views: 515143

Re: Official V4L2 driver

Thanks
by nutron
Wed Aug 28, 2019 8:24 pm
Forum: Camera board
Topic: Official V4L2 driver
Replies: 561
Views: 515143

Re: Official V4L2 driver

Could somebody tell me what the /dev/video10 video11 video12 devices are for ?

Are they generated by v4l2 for some purpose ?
by nutron
Wed Aug 28, 2019 8:15 pm
Forum: Raspberry Pi OS
Topic: what are the video10 / video11 / video12 devices for?
Replies: 5
Views: 2354

Re: what are the video10 / video11 / video12 devices for?

maybe they are loopbacks for streaming or screen capturing.
by nutron
Wed Aug 28, 2019 7:06 pm
Forum: Raspberry Pi OS
Topic: what are the video10 / video11 / video12 devices for?
Replies: 5
Views: 2354

Re: what are the video10 / video11 / video12 devices for?

Must be new i guess.

V4l2 used to create extra device on demand and not by default.
by nutron
Wed Aug 28, 2019 2:15 pm
Forum: Raspberry Pi OS
Topic: what are the video10 / video11 / video12 devices for?
Replies: 5
Views: 2354

what are the video10 / video11 / video12 devices for?

Hi guys. I upgraded to stretch / buster and noticed that there are 3 video devices in the DEV folder. I have no video capture devices connected to the PI . I also did a fresh installation of stretch / buster to make sure it is not some residue from a previous raspian installation and the result is t...
by nutron
Sat Apr 28, 2018 3:42 am
Forum: Camera board
Topic: Picamera overlay update function causing high CPU load
Replies: 0
Views: 341

Picamera overlay update function causing high CPU load

Could somebody please give me a hint why using the overlay update function is causing a very high CPU load on the Raspberry Pi3 ? The only way to reduce the load is to remove the overlay renderer. This bit of the code is where the issue lies , that i know of. Before this bit i just create an image w...

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