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by pcmanbob
Sat Oct 01, 2022 1:41 pm
Forum: Troubleshooting
Topic: Raspberry Pi non-boot - constant green led rapid flashing
Replies: 1
Views: 52

Re: Raspberry Pi non-boot - constant green led rapid flashing

Hi.

If you boot your pi with just a display connected do you get the diagnostic screen, I would also suggest unplugging the fan when you try this.

As your small screen may not be compatible with the pi , I would suggest connecting the pi to a TV which an HDMI port as it should just work.
by pcmanbob
Sat Oct 01, 2022 11:41 am
Forum: Automation, sensing and robotics
Topic: Looking for a hatch to drop and item when going down and then eturn up to a fixed position
Replies: 5
Views: 257

Re: Looking for a hatch to drop and item when going down and then eturn up to a fixed position

But that's not going to happen because we have no idea of any of the details of the required hatch.

You would need to provide a complete set of specifications of the hatch/mechanism for anyone to find a ready made one,
and that's something you can do yourself especially as you know what you want.
by pcmanbob
Sat Oct 01, 2022 8:22 am
Forum: Automation, sensing and robotics
Topic: Looking for a hatch to drop and item when going down and then eturn up to a fixed position
Replies: 5
Views: 257

Re: Looking for a hatch to drop and item when going down and then eturn up to a fixed position

So if the hatch is locked in the up position by some other device, then you could use a stepper motor to do the lifting. loop would go like this assuming we start with hatch closed. Hatch released to fall open. Stepper runs lifting hatch > hatch locks in closed position stepper motor continues to ru...
by pcmanbob
Fri Sep 30, 2022 8:02 am
Forum: Troubleshooting
Topic: Raspberry pi 4 showing green light for 2 seconds on startup and going blank afterwards
Replies: 1
Views: 123

Re: Raspberry pi 4 showing green light for 2 seconds on startup and going blank afterwards

Well if your pi had failed when you return to it to find water on it then it suggested the water has probably caused a short circuit damaging one or more components on the pi. If drying it and then trying to boot it did not work it suggests the damage may be permanent. If you power the pi with no SD...
by pcmanbob
Wed Sep 28, 2022 11:46 am
Forum: Troubleshooting
Topic: Detect 15V AC on Raspberry GPIO
Replies: 21
Views: 536

Re: Detect 15V AC on Raspberry GPIO

When using an opto isolator its worth looking for one designed for AC input , they have 2 LED's connected opposite to each other so you don't have to worry about reverse voltages.

once such example https://www.vishay.com/docs/83608/h11aa1.pdf
by pcmanbob
Wed Sep 28, 2022 11:25 am
Forum: General discussion
Topic: static and susceptible circuits
Replies: 2
Views: 162

Re: static and susceptible circuits

I don't see it affecting the components or the circuits, just make sure you ground yourself , before handling/unpacking them, by touching a grounded water/gas/heating pipe or a ground metal appliance that's plugged in to a grounded socket, as you are more likely to damage your devices from static yo...
by pcmanbob
Mon Sep 26, 2022 8:49 am
Forum: Troubleshooting
Topic: Pi 3B crashes on boot?
Replies: 3
Views: 182

Re: Pi 3B crashes on boot?

Sorry I don't have any pi's running the desktop version of the OS they are all running lite and running heedless so no screen or keyboard attached.
by pcmanbob
Sun Sep 25, 2022 12:55 pm
Forum: Troubleshooting
Topic: Pi 3B crashes on boot?
Replies: 3
Views: 182

Re: Pi 3B crashes on boot?

Hi. It may be that your pi is actually booting ok but your screen is not reporting the correct information so the pi will not support it. There are a couple of options to try 1. When creating the user/password for the new image also enable ssh, then connect your pi to the network using a wired conne...
by pcmanbob
Sat Sep 24, 2022 3:41 pm
Forum: Troubleshooting
Topic: Raspberry 3B+ "no wireless interfaces found" after dist upgrade
Replies: 3
Views: 151

Re: Raspberry 3B+ "no wireless interfaces found" after dist upgrade

Assuming you fresh install is on another SD card try doing the updates with the commands sudo apt update sudo apt full-upgrade Assuming this works and you can connect wirelessly after a reboot, boot the pi from the original / faulty SD card and connect to network using wired connection , if you can ...
by pcmanbob
Fri Sep 23, 2022 9:08 am
Forum: Other projects
Topic: N.A.S. Monster
Replies: 4
Views: 385

Re: N.A.S. Monster

Hi.

Did you not do any research ;)

just one of many nas projects using the pi on YouTube

https://www.youtube.com/watch?v=BBnomwpF_uY

I picked this one because it had so many drives connected and I was already aware of its existence.
by pcmanbob
Thu Sep 22, 2022 12:38 pm
Forum: Beginners
Topic: Initialize Gpio on startup
Replies: 9
Views: 361

Re: Initialize Gpio on startup

Well I would test the gpio pins with an LED like this just to prove what the pins are actually being set to.

GPIO 12 shown
Image

R1 can be any resistor value between 200 and 470 ohms
by pcmanbob
Thu Sep 22, 2022 12:00 pm
Forum: Compute Module
Topic: Who to talk to about CM4 packaging during delivery?
Replies: 8
Views: 509

Re: Who to talk to about CM4 packaging during delivery?

How about the person / company you are buying them from, using the same contact details you used to place the order.
by pcmanbob
Thu Sep 22, 2022 11:57 am
Forum: Troubleshooting
Topic: Raspberry pi 4 DS18B20 not working permanently
Replies: 3
Views: 158

Re: Raspberry pi 4 DS18B20 not working permanently

You say it was working fine on a pi2, have you tried putting it back on the pi2 just to make sure its not a fault with one of the sensors ? You say the cable to the first sensor is 10CM and the cable to the second is 1M so is you 1M cable connected to the first sensor or directly to the pi ? I don't...
by pcmanbob
Thu Sep 22, 2022 10:10 am
Forum: Beginners
Topic: Initialize Gpio on startup
Replies: 9
Views: 361

Re: Initialize Gpio on startup

When you tired to do it in config.txt did you use the correct commands/gpio numbers remembering that these are BCM numbers and not pin numbers ? https://forums.raspberrypi.com/viewtopic.php?t=208748 So for example gpio 12( bcm) which is pin 32 # Set GPIO12 to be an output set to 0 ( low) gpio=12=op,dl
by pcmanbob
Thu Sep 22, 2022 9:59 am
Forum: Gaming
Topic: Retropie not working
Replies: 1
Views: 176

Re: Retropie not working

Hi.

The people to ask about this are retropie they have their own support forum at https://retropie.org.uk/forum/
by pcmanbob
Wed Sep 21, 2022 9:09 am
Forum: Troubleshooting
Topic: Raspberry 3B+ "no wireless interfaces found" after dist upgrade
Replies: 3
Views: 151

Re: Raspberry 3B+ "no wireless interfaces found" after dist upgrade

The first thing I would suggest is to get another SD card and put a fresh copy of RPI OS on it and boot the pi from that,
this will tell you if its a software problem with your existing SD card/OS or a hardware problem with the pi its self.
by pcmanbob
Tue Sep 20, 2022 7:53 am
Forum: Python
Topic: I'm having trouble coding a CPU and Activity on the 16 x 2 Character LCD
Replies: 33
Views: 1003

Re: I'm having trouble coding a CPU and Activity on the 16 x 2 Character LCD

So I looked at your line " temp-f = int( ( temp × (9/5))+ 32 )" first off you should be using "*" and not "x" for multiplication, your other problem seems to be in using " temp-f " as a variable name , python is trying to do a subtraction of temp minus f , bec...
by pcmanbob
Sun Sep 18, 2022 9:26 am
Forum: Beginners
Topic: msmtp. Resend email which failed.
Replies: 1
Views: 116

Re: msmtp. Resend email which failed.

I guess there are a couple of ways to approach this. 1. Check for an internet connection before sending the mains and if not present then delay sending and test again and again till there is an internet connection. 2. If the fail to send the email generates an error message then trap the error messa...
by pcmanbob
Thu Sep 15, 2022 8:05 am
Forum: Troubleshooting
Topic: No APs found
Replies: 1
Views: 104

Re: No APs found

Hi.

You have not provided any information on which anyone can base even a guess as to what is wrong, you need to provide at least the following

which pi

which OS are you running

post a copy of dhcpcd.conf file

and any other relevant information especially any other changes you have made.
by pcmanbob
Wed Sep 14, 2022 10:23 am
Forum: Troubleshooting
Topic: Help repairing Pi4 fault on USB regulator IC
Replies: 4
Views: 155

Re: Help repairing Pi4 fault on USB regulator IC

That would explain why searching with the number I posted returned not parts from any of the electronic component suppliers.
by pcmanbob
Wed Sep 14, 2022 10:04 am
Forum: Troubleshooting
Topic: Help repairing Pi4 fault on USB regulator IC
Replies: 4
Views: 155

Re: Help repairing Pi4 fault on USB regulator IC

Assuming its the same on all pi4's and I am looking at the correct part.

part number is BJ9RA

Image
by pcmanbob
Wed Sep 14, 2022 9:49 am
Forum: Troubleshooting
Topic: Invisible rectangular "boundary" in top left corner of VNC display
Replies: 7
Views: 253

Re: Invisible rectangular "boundary" in top left corner of VNC display

Out of interest what happens if you move the task bar to the bottom of the screen,

Does the problem move with it ?
by pcmanbob
Tue Sep 13, 2022 2:11 pm
Forum: Troubleshooting
Topic: Invisible rectangular "boundary" in top left corner of VNC display
Replies: 7
Views: 253

Re: Invisible rectangular "boundary" in top left corner of VNC display

Try doing the update from the command line or terminal window using

Code: Select all

sudo apt update
sudo apt full-upgrade
May be the is a problem with a dependency or one is not bing included,

you should be able to see more feed back by doing it this way.
by pcmanbob
Tue Sep 13, 2022 2:04 pm
Forum: Troubleshooting
Topic: Raspberry pi 4 DS18B20 not working permanently
Replies: 3
Views: 158

Re: Raspberry pi 4 DS18B20 not working permanently

Hi.

To use these devices on a pi you really need the 4.7K ohm pull up resistor, connected like this.

Image

If you sensors keep disappearing but hen return by them selves that could be a indication of a bad connection in the wiring/sensor/pi connections.
by pcmanbob
Mon Sep 12, 2022 9:44 am
Forum: Troubleshooting
Topic: Crontab not working
Replies: 5
Views: 159

Re: Crontab not working

Hi.

As cron runs in the background nothing you attempt to do in your script will affect the desktop, as cron has no association with it.

You will probably need to install something to run scheduling from the desktop like gnome-schedule.
I can't off any help with this because I don't use it myself.

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