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by evilkitty
Sat Mar 23, 2019 10:31 pm
Forum: Raspbian
Topic: syslog: Under-voltage detected!
Replies: 14
Views: 3347

Re: syslog: Under-voltage detected!

my vdrop is 0.1 (idle) to 0.2 (stress test)
psu is at 5.2v
voltage spec is 5.25 - 4.75
to go below 4.75v i would need to pull about twice what is pulled with a 4 core stress test
by evilkitty
Sat Mar 23, 2019 8:37 pm
Forum: Raspbian
Topic: syslog: Under-voltage detected!
Replies: 14
Views: 3347

Re: syslog: Under-voltage detected!

via the micro usb plug, the wire is about 6 inches of solid core wire i got out of a piece of scrap ethernet cable *this wire only powers the pi and the flash drive the USB modem get power from upstream from the main power leads (18awg stranded, this is 6 to 8 inches long) this pi runs headless so t...
by evilkitty
Sat Mar 23, 2019 8:05 pm
Forum: Raspbian
Topic: syslog: Under-voltage detected!
Replies: 14
Views: 3347

Re: syslog: Under-voltage detected!

log file shows it lasted 6 seconds, i would think a DMM would be fast enough for that The board is the Raspberry Pi 3 Model B+ power supply is a EPS-15-5 set at 5.2v [email protected]:~ $ lsb_release -a No LSB modules are available. Distributor ID: Raspbian Description: Raspbian GNU/Linux 9.4 (stretch)...
by evilkitty
Sat Mar 23, 2019 7:04 pm
Forum: Raspbian
Topic: syslog: Under-voltage detected!
Replies: 14
Views: 3347

Re: syslog: Under-voltage detected!

I managed to trigger low voltage while my multimeter reads a nice safe 5v on the pi's USB port It seems if my network switch is power cycled while the pi's network jack is connected to the switch [email protected]:~ $ cat /var/log/syslog | grep -i voltage -A1 -B1 Mar 23 14:05:54 raspberrypi rc.local[44...
by evilkitty
Mon Jan 21, 2019 1:43 am
Forum: Automation, sensing and robotics
Topic: Convert low frequency PWM 1Khz to high frequency PWM 25Khz
Replies: 5
Views: 584

Re: Convert low frequency PWM 1Khz to high frequency PWM 25Khz

The buck converter would be a dedicated hardware circuit controlled by a pwm signal, so i would feed a voltage regulator a pwm single (or it's feedback input) I want to be able to control the duty cycle on the fly from the host system aside from that part i want some 25Khz PWM singles so i can shove...
by evilkitty
Sat Jan 19, 2019 11:08 pm
Forum: Automation, sensing and robotics
Topic: Convert low frequency PWM 1Khz to high frequency PWM 25Khz
Replies: 5
Views: 584

Re: Convert low frequency PWM 1Khz to high frequency PWM 25Khz

The reason for using a 1Khz freq is that is what the source ( A FF32 chip ) has to work with i had the feedback type of control in mind as for the buck converter i have, i do not have one i need to know what i need to get to build a circuit maybe a arduino would be better suited for this, but i do n...
by evilkitty
Sat Jan 19, 2019 9:32 pm
Forum: Automation, sensing and robotics
Topic: Convert low frequency PWM 1Khz to high frequency PWM 25Khz
Replies: 5
Views: 584

Convert low frequency PWM 1Khz to high frequency PWM 25Khz

What is a IC I can feed a 1Khz single into that will output a 25Khz frequency If it supports 4 in and out that would be great Also if anyone knows of a easy way to use a buck converter so i can take 12VDC and output 0-12VDC with a 1Khz PWM single that would be awesome, max output would be no more th...
by evilkitty
Sun Sep 02, 2018 8:39 pm
Forum: Raspbian
Topic: GPIO Pin Setup fails on occasion (Can you reproduce this?)
Replies: 6
Views: 619

Re: GPIO Pin Setup fails on occasion (Can you reproduce this?)

updated kernel, it now seems as though the probability of this issue happening has dropped
at this point i have to run both test 1 and test 2 at the same time to get it to happen
by evilkitty
Sun Sep 02, 2018 8:35 pm
Forum: Raspbian
Topic: syslog: Under-voltage detected!
Replies: 14
Views: 3347

Re: syslog: Under-voltage detected!

The thing is after i opened the case and got my meter hooked up the the board instead of a usb cable, the issue disappeared and the voltage came up to over 5.05v from <=4.8, this was after i checked the power from the psu and found 5.2 to 5.19 maybe the psu got hot and was dropping volts, that or th...
by evilkitty
Sun Sep 02, 2018 1:32 pm
Forum: Raspbian
Topic: syslog: Under-voltage detected!
Replies: 14
Views: 3347

Re: syslog: Under-voltage detected!

So if i were to use a ADC chip like a MCP3002 that i saw suggested on the forums, how would i wire it and read it in software? it said it was easy to program, but does that mean flashing the is with a rom file? if so details i have never flashed a ic (well i have flashed routers, motherboards, and v...
by evilkitty
Sun Sep 02, 2018 10:21 am
Forum: Raspbian
Topic: syslog: Under-voltage detected!
Replies: 14
Views: 3347

Re: syslog: Under-voltage detected!

I found out you can use this file for a power good check /sys/class/leds/led1/brightness 255 = good/usable and 0 = very bad (<=4.63v) but in regards to throttling https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=147781&start=50#p972790 how do i convert between this list as stuff like 0x50005,...
by evilkitty
Sun Sep 02, 2018 12:41 am
Forum: Raspbian
Topic: syslog: Under-voltage detected!
Replies: 14
Views: 3347

syslog: Under-voltage detected!

my sys log is filled with entries like this: https://pastebin.com/pbEVR2RT Sep 1 06:25:07 raspberrypi kernel: [3316534.286203] Voltage normalised (0x00000000) Sep 1 07:05:03 raspberrypi kernel: [3318930.470847] Under-voltage detected! (0x00050005) Sep 1 07:05:08 raspberrypi kernel: [3318934.630893] ...
by evilkitty
Sat Sep 01, 2018 10:31 pm
Forum: Raspbian
Topic: GPIO Pin Setup fails on occasion (Can you reproduce this?)
Replies: 6
Views: 619

Re: GPIO Pin Setup fails on occasion (Can you reproduce this?)

Nothing in syslog, but i do see some undervoltage entries, 0x005005 and of course once you hook up a multi-meter they stop happening based on the time stamps they are unrelated I am using a legitimate 3A power supply and i am not even use half of it I am only monitoring it via the sysfs, the python ...
by evilkitty
Sat Sep 01, 2018 9:02 pm
Forum: Raspbian
Topic: GPIO Pin Setup fails on occasion (Can you reproduce this?)
Replies: 6
Views: 619

Re: GPIO Pin Setup fails on occasion (Can you reproduce this?)

GPIO.setup sets the logic direction, the pin will be either a input or a output an input is for read only and the script can monitor the state of the pin for change an output is used for controlling something In my case i am measuring how long it takes a capacitor to charge, but to take a new measur...
by evilkitty
Sat Sep 01, 2018 8:11 pm
Forum: General discussion
Topic: Delidding CPU
Replies: 37
Views: 2643

Re: Delidding CPU

I'm wondering how anyone could get the idea that removing the lid from a chip could have any benefits. Probably a result on intel use paste instead of solder between the die and the IHS of there processors, this lead to some people using liquid metal to replace the paste, this process is normally r...
by evilkitty
Sat Sep 01, 2018 8:04 pm
Forum: Raspbian
Topic: GPIO Pin Setup fails on occasion (Can you reproduce this?)
Replies: 6
Views: 619

Re: GPIO Pin Setup fails on occasion (Can you reproduce this?)

I made a couple scripts to test for a software issue Here is a screen shot of my test: https://i.imgur.com/0zgfHhI.png In both test cases there is nothing connected to the logic pins They were conducted at the same time in test case one we just set the pin mode every 0.25 seconds Results: [email protected]...
by evilkitty
Sat Jul 07, 2018 7:35 pm
Forum: Automation, sensing and robotics
Topic: What does it take to kill a DS18B20?
Replies: 5
Views: 640

Re: What does it take to kill a DS18B20?

What does it default to? i probably should check gpio 2/3 for damage [email protected]:/sys/class/gpio $ uname -r 4.9.35+ [email protected]:/sys/class/gpio $ lsb_release -a No LSB modules are available. Distributor ID: Raspbian Description: Raspbian GNU/Linux 8.0 (jessie) Release: 8.0 Codename: jessie Ras...
by evilkitty
Sat Jul 07, 2018 4:58 pm
Forum: Automation, sensing and robotics
Topic: What does it take to kill a DS18B20?
Replies: 5
Views: 640

Re: What does it take to kill a DS18B20?

It looks like i probably lost my GPIO pin for the temp-sensor along with the sensor [email protected]:~ $ echo 4 > /sys/class/gpio/export [email protected]:~ $ cd /sys/class/gpio/gpio gpio4/ gpiochip0/ [email protected]:~ $ cd /sys/class/gpio/gpio4 [email protected]:/sys/class/gpio/gpio4 $ ls active_low device ...
by evilkitty
Sat Jul 07, 2018 1:27 pm
Forum: Automation, sensing and robotics
Topic: What does it take to kill a DS18B20?
Replies: 5
Views: 640

Re: What does it take to kill a DS18B20?

I have the circuit on a soldered pcb (Is it really a P CB if you use double sided prototyping board?) i even connected it to a diff pi to be sure the GPIO was good and used my multi-meter to check the rest i know that sensor can handle a lot of abuse with how hot i have gotten them by putting them i...
by evilkitty
Sat Jul 07, 2018 2:01 am
Forum: Automation, sensing and robotics
Topic: What does it take to kill a DS18B20?
Replies: 5
Views: 640

What does it take to kill a DS18B20?

I had a properly wired B18B20 that has been working for a few years now just die along with a LED around the time the sensor stopped responding there was a thunderstom in the area and the rPi did not loose power and the board still works fine i had a LED powered by the same wire as the sensor that i...
by evilkitty
Wed Jun 13, 2018 10:47 am
Forum: Troubleshooting
Topic: Apache2 will not start; lack of error data; SIGTERM?
Replies: 1
Views: 316

Re: Apache2 will not start; lack of error data; SIGTERM?

This pi normally gets updated via the unattended-upgrade package after a dist-upgrade and a reboot it is now running (a reboot did not fix it before) [email protected]:/etc/apache2 $ sudo apt-get dist-upgrade -y Reading package lists... Done Building dependency tree Reading state information... Done Ca...
by evilkitty
Wed Jun 13, 2018 10:29 am
Forum: Troubleshooting
Topic: Apache2 will not start; lack of error data; SIGTERM?
Replies: 1
Views: 316

Apache2 will not start; lack of error data; SIGTERM?

It stopped running between 17:00 and 21:00 on Jun 12 i tried to debug it but the lack of error info has stumped me, the most useful thing i have found is s seg fault when running a debug command i tried reinstalling apache2 to no avail Every error log file: [email protected]:/etc/apache2 $ cat /var/log...
by evilkitty
Thu Apr 26, 2018 12:27 am
Forum: Raspbian
Topic: GPIO Pin Setup fails on occasion (Can you reproduce this?)
Replies: 6
Views: 619

GPIO Pin Setup fails on occasion (Can you reproduce this?)

I am using a model 3B+ Raspbian Stretch lite .',;:cc;,'. .,;::c:,,. [email protected] ,ooolcloooo: 'oooooccloo: OS: Raspbian 9.4 stretch .looooc;;:ol :oc;;:ooooo' Kernel: armv7l Linux 4.9.80-v7+ ;oooooo: ,ooooooc. Uptime: 38d 3h 46m .,:;'. .;:;'. Packages: 737 .dQ. .d0Q0Q0. '0Q. Shell: bash 4.4.12 .0Q0...
by evilkitty
Sat Apr 21, 2018 8:46 pm
Forum: Raspbian
Topic: Verify that pin GPIO setup value
Replies: 2
Views: 333

Re: Verify that pin GPIO setup value

def RCtest (RCpin,limit): reading = 0 piwiring.pinMode(RCpin, 1) piwiring.digitalWrite(RCpin, 0) sleep(1) piwiring.pinMode(RCpin, 0) while (piwiring.digitalRead(RCpin) == 0): reading += 1 sleep(0.005) if(reading>limit): with open('/sys/class/gpio/gpio8/direction') as f: first_line = f.readline().st...
by evilkitty
Wed Apr 18, 2018 11:14 am
Forum: Raspbian
Topic: Verify that pin GPIO setup value
Replies: 2
Views: 333

Verify that pin GPIO setup value

Is there a way via software i can make sure that RCpin was infant successfully setup as a input? def RCtest (RCpin,limit): reading = 0 GPIO.setup(RCpin, GPIO.OUT) GPIO.output(RCpin, 0) sleep(0.1) GPIO.setup(RCpin, GPIO.IN) # I want to verify this did work while (GPIO.input(RCpin) == 0): reading += 1...

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