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by jbudd
Sat Nov 30, 2019 3:17 pm
Forum: Beginners
Topic: Setting Up Raspberry Pi 4 with ethernet cable
Replies: 2
Views: 94

Re: Setting Up Raspberry Pi 4 with ethernet cable

Why do you need the Pis IP address , name? Are you trying to set it up without a keyboard and monitor?
Where does the ethernet cable go to?
Did you load NOOBS or Raspbian onto your SD card?
by jbudd
Sat Nov 30, 2019 5:48 am
Forum: General discussion
Topic: Pi4 Performance testing
Replies: 5
Views: 321

Re: Pi4 Performance testing

In Node-Red: Hamburger menu | Manage Palette | Install tab. Search for node-red-dashboard and Install
by jbudd
Sat Nov 30, 2019 12:44 am
Forum: General discussion
Topic: Pi4 Performance testing
Replies: 5
Views: 321

Re: Pi4 Performance testing

Here is a simplified reconstruction of the graph in the blog - no moving average, frequency scaled to work with a common y axis, etc. A script to gather the statistics pi@RainbowPi:~ $ cat foo.py #! /usr/bin/env python import os import time time.sleep(1) # CPU frequency - do this first hoping to cat...
by jbudd
Fri Nov 29, 2019 12:52 am
Forum: General discussion
Topic: Pi4 Performance testing
Replies: 5
Views: 321

Re: Pi4 Performance testing

The line graphs look like fairly simple Node-Red time series charts using the node-red-dashboard functions.

I use it to draw a similar temperature and frequency graph for my Pi, will happily share the code if you want it
by jbudd
Thu Nov 21, 2019 10:59 am
Forum: General discussion
Topic: Enabling and connecting to a raspberry pi
Replies: 9
Views: 429

Re: Enabling and connecting to a raspberry pi

After imaging my SD card with Win32Diskimager as a back-up procedure
Is it possible that you overwrote the SD card rather than reading it?
You could test that by putting wpa_supplicant.conf and ssh.txt in the boot folder, see if you can connect then.
by jbudd
Tue Nov 19, 2019 4:36 pm
Forum: General discussion
Topic: Transferring data from Raspberry Pi 2 to Raspberry Pi 4
Replies: 13
Views: 433

Re: Transferring data from Raspberry Pi 2 to Raspberry Pi 4

I have dozens of micro sd cards and tiny USB drives; I can never find them when I want them. I even have trouble finding my Pi Zero sometimes. One note regarding tar... It preserves ownership based on the UID and GID, so if such are not the same on both systems, you may get unexpected results. Proba...
by jbudd
Tue Nov 19, 2019 2:00 pm
Forum: General discussion
Topic: Transferring data from Raspberry Pi 2 to Raspberry Pi 4
Replies: 13
Views: 433

Re: Transferring data from Raspberry Pi 2 to Raspberry Pi 4

However, promoting it [using the SD boot partition] is a disservice to the community as it is pretty much the worst way you can move data between Pis. In an emergency, sure, you do what you have to do. But teaching it as a suggested method is just wrong. Well it's useful to know about for specific ...
by jbudd
Wed Nov 13, 2019 10:41 am
Forum: General discussion
Topic: LRF sensor for raspberry pi
Replies: 7
Views: 214

Re: LRF sensor for raspberry pi

The VL53LOX works well but only for a range of up to about 1 metre. I guess you could use it to detect people passing through a doorway.
https://www.adafruit.com/product/3317
by jbudd
Wed Nov 13, 2019 12:07 am
Forum: Beginners
Topic: Simple weather station Raspberry Pi Sense Hat vs Waveshare Sense Hat (B)
Replies: 5
Views: 226

Re: Simple weather station Raspberry Pi Sense Hat vs Waveshare Sense Hat (B)

I don't think that a board mounted on top of the Pi is ideal for a weather station. Pies get warm which will mess up your temperature and humidity readings. Better to get a BME280 board (make sure it has all three sensors) and connect it at a little distance from the Pi. Or even connect it to an ESP...
by jbudd
Sat Nov 09, 2019 2:08 pm
Forum: General discussion
Topic: What is the maximum temperature of the CPU before it gets demaged ?
Replies: 14
Views: 784

Re: What is the maximum temperature of the CPU before it gets demaged ?

Hmm I knew about changes for network booting, didn't realise the bootcode also related to thermal issues. So "firmware" version is revealed by sudo vl805 (000137ab) It is updated by apt update and possibly at every boot. (I don't like that but I guess it's important to keep bootcode and kernel in sy...
by jbudd
Sat Nov 09, 2019 1:14 pm
Forum: General discussion
Topic: What is the maximum temperature of the CPU before it gets demaged ?
Replies: 14
Views: 784

Re: What is the maximum temperature of the CPU before it gets demaged ?

With the latest firmware, there seems to be no risk of even reaching 85C now. Is "firmware" different from the kernel version as shown by uname -r ? If it is, does it get updated by apt update ? How do we tell what version we have? My Pi4 does seem to run cooler than it first did. I'd put it down t...
by jbudd
Sat Nov 09, 2019 12:32 pm
Forum: General discussion
Topic: What is the maximum temperature of the CPU before it gets demaged ?
Replies: 14
Views: 784

Re: What is the maximum temperature of the CPU before it gets demaged ?

You don't actually need to write a program for this, it is possible to control a fan automatically using a device tree overlay and a transistor- For example, this line in /boot/config.txt will set GPIO 12 high when the CPU temperature reaches 65C and low again when it cools down by 10 degrees. dtove...
by jbudd
Fri Nov 08, 2019 4:58 pm
Forum: General discussion
Topic: Err_address_unreachable
Replies: 2
Views: 120

Re: Err_address_unreachable

This sounds like IPv6 is working but IPv4 is messed up.

Have you tried to give the PC a static IP address? - How, why?

Have you made any changes to /etc/network/interfaces?
Have you made any changes to /etc/dhcpcd.conf?
by jbudd
Fri Nov 08, 2019 4:21 pm
Forum: General discussion
Topic: minimal rpi4 hw
Replies: 7
Views: 240

Re: minimal rpi4 hw

Speaking minimally, you don't need to buy a case. Lots of Pies run naked.
But if you do buy a case you can surely do without those "heatsinks", the fan will be more than adequate to keep it cool[ish].
by jbudd
Fri Nov 08, 2019 11:33 am
Forum: Beginners
Topic: Connecting to Wifi without a screen or keyboard
Replies: 4
Views: 140

Re: Connecting to Wifi without a screen or keyboard

My original thought was that when I arrive at a new location: Pull the SD card out of the Pi Plug SD card into a USB reader Plug USB reader into either laptop (Windows) or phone (Android) Modify /etc/wpa_supplicant/wpa_supplicant.conf file with the username & password for the wifi. Plug the SD card...
by jbudd
Tue Nov 05, 2019 4:01 pm
Forum: General discussion
Topic: Access Raspberry Pi 3 A+ with USB and SSH
Replies: 14
Views: 717

Re: Access Raspberry Pi 3 A+ with USB and SSH

mattmiller wrote:
Tue Nov 05, 2019 3:43 pm
You don't fancy writing it do you? :)
Send me a robot and i'll consider it!
by jbudd
Tue Nov 05, 2019 3:34 pm
Forum: General discussion
Topic: Access Raspberry Pi 3 A+ with USB and SSH
Replies: 14
Views: 717

Re: Access Raspberry Pi 3 A+ with USB and SSH

You could include a program to run at boot which checks for a file "wifi.txt" on a USB memory stick and updates wpa_supplicant.conf with the contents.

It would ideally:
- Work with different Wifi encryption modes besides WPA2
- Verify the data
- Update or add the country code
by jbudd
Tue Nov 05, 2019 3:26 pm
Forum: General discussion
Topic: Persistent SD Card Corruption
Replies: 16
Views: 1338

Re: Persistent SD Card Corruption

The URL you posted tries to download a file. No thanks!
by jbudd
Tue Nov 05, 2019 3:20 pm
Forum: General discussion
Topic: Access Raspberry Pi 3 A+ with USB and SSH
Replies: 14
Views: 717

Re: Access Raspberry Pi 3 A+ with USB and SSH

I'm sorry, I have never had a Pi so securely encased that I couldn't reach the SD card slot so I can't help you. There is a description of what you are trying to do at https://www.factoryforward.com/pi-zero-w-headless-setup-windows10-rndis-driver-issue-resolved/ . No idea if it works with Raspbian B...
by jbudd
Tue Nov 05, 2019 2:58 pm
Forum: General discussion
Topic: Access Raspberry Pi 3 A+ with USB and SSH
Replies: 14
Views: 717

Re: Access Raspberry Pi 3 A+ with USB and SSH

If you have wifi there is no need to connect PC and Pi with a USB cable. Just create the wpa_supplicant.conf file, including your wifi credentials, on your PC. Put it in the boot partition of the sd card, then boot the Pi. It should connect to your WiFi. The correct command is ssh pi@raspberrypi.loc...
by jbudd
Tue Oct 29, 2019 1:58 pm
Forum: General discussion
Topic: What is network boot, and why?
Replies: 7
Views: 427

Re: What is network boot, and why?

Thanks very much for your replies. Much food for thought!
by jbudd
Tue Oct 29, 2019 12:35 pm
Forum: General discussion
Topic: What is network boot, and why?
Replies: 7
Views: 427

What is network boot, and why?

According to Wikipedia: "In the late 1980s/early 1990s, network boot was used to save the expense of a disk drive". That's just about the extent of my knowledge of the subject! So network booting a Pi means no SD card, perhaps no local storage at all on the Pi? In what circumstances is this an advan...
by jbudd
Mon Oct 28, 2019 10:28 pm
Forum: Troubleshooting
Topic: RPi 4 - No monitor signal and SD card becoming write protected
Replies: 2
Views: 200

Re: RPi 4 - No monitor signal and SD card becoming write protected

No doubt NOOBS is excellent software but to me it's just something else to go wrong. Try downloading Raspbian and burning it to your sd card with Etcher. If necessary get a third sd, but just possibly it will work with the second one. Do you have an HDMI monitor and a micro HDMI cable or are you usi...
by jbudd
Sun Oct 27, 2019 11:52 pm
Forum: General discussion
Topic: I want to push a button to send a preconfigured email
Replies: 13
Views: 869

Re: I want to push a button to send a preconfigured email

Here's a little shell script to send one of a variety of subjects. You could call this from your python program, passing the email subject number as a parameter. Of course it can be done in python too... #! /bin/bash MAILTO=xxxxxxx@xxxxx.xxx SUBJECTS=("Subject #0" "Subject #1" "Subject #2" "Subject ...

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