Go to advanced search

by mikerr
Thu Jul 04, 2019 2:14 pm
Forum: General discussion
Topic: Just received my RPi4b/4GB - no HDMI output!!!
Replies: 75
Views: 4046

Re: Just received my RPi4b/4GB - no HDMI output!!!

NOOBS currently sets some incorrect flags for HDMI1 in config.txt for the underlying OS (hdmi_force_hotplug=1). Your comment "It's a normal hdmi cable with micro hdmi adapter on it." implies you're using HDMI1 (as the blob adapters don't fit in HDMI0 as they hit the power connector). I'm confused a...
by mikerr
Thu Jul 04, 2019 11:38 am
Forum: General discussion
Topic: Just received my RPi4b/4GB - no HDMI output!!!
Replies: 75
Views: 4046

Re: Just received my RPi4b/4GB - no HDMI output!!!

6by9 wrote:
Thu Jul 04, 2019 11:25 am
Hotplug has never been supported on the Pi.
Unless you put hdmi_force_hotplug=1 in config.txt
That's usually the first thing I do.
by mikerr
Thu Jul 04, 2019 9:19 am
Forum: Raspbian
Topic: Diffenreces in Raspbians?
Replies: 4
Views: 243

Re: Diffenreces in Raspbians?

3 versions: Raspbian Lite Boots to a command line, no desktop installed 400MB download, 2.2GB installed Raspbian desktop Desktop with Chrome, VLC, Geany & Thonny. 1GB download, 3.6GB installed Raspbian full desktop & all apps Desktop with: Chrome, VLC, Geany & Thonny BlueJ, Greenfoot, Mu, Node-RED, ...
by mikerr
Thu Jul 04, 2019 8:46 am
Forum: General discussion
Topic: Raspberry Pi 4 Thread - general discussion
Replies: 752
Views: 64362

Re: Raspberry Pi 4 Thread - general discussion

What info does the qr barcode on the bottom show ?

I was hoping it was the serial number like on tinkerboard, but it doesn't seem to be:

Image
by mikerr
Tue Jul 02, 2019 8:00 pm
Forum: General discussion
Topic: Just received my RPi4b/4GB - no HDMI output!!!
Replies: 75
Views: 4046

Re: Just received my RPi4b/4GB - no HDMI output!!!

k-pi wrote:
Tue Jul 02, 2019 7:51 pm
Altered config.txt
hdmi_force_hotplug=1
hdmi_group=2

But still only getting 1024x768, every time I alter it in the Screen Layout Editor to 1366x768 & apply it, it reverts back to 1024x768!
Add
hdmi_mode=81
for 1366x768 ?
by mikerr
Tue Jul 02, 2019 7:12 pm
Forum: General discussion
Topic: Just received my RPi4b/4GB - no HDMI output!!!
Replies: 75
Views: 4046

Re: Just received my RPi4b/4GB - no HDMI output!!!

Hdmi-safe does force-hotplug and more,
including setting a low resolution as you've found.

https://www.raspberrypi.org/documentati ... t/video.md

Is that the official PSU, or a capable one ?
The pi4 draws alot more power than the pi3, and peaks just after the logo....
by mikerr
Tue Jul 02, 2019 6:40 pm
Forum: General discussion
Topic: Just received my RPi4b/4GB - no HDMI output!!!
Replies: 75
Views: 4046

Re: Just received my RPi4b/4GB - no HDMI output!!!

So, just tried powering up the monitor & then the RPi4B once the monitor is on, separately like we used to have to do, & still no HDMI output. If you put this line in config.txt hdmi_force_hotplug=1 it won't matter which order you power or connect screen & pi. Worth doing if you're getting blank/no...
by mikerr
Sat Jun 29, 2019 12:04 pm
Forum: General discussion
Topic: Power Raspberry Pi 4 via 40 pin connector?
Replies: 11
Views: 1109

Re: Power Raspberry Pi 4 via 40 pin connector?

Yes, just be aware the pi4 draws quite a bit more than previous models
https://raspi.tv/2019/how-much-power-do ... asurements
by mikerr
Fri Jun 28, 2019 4:24 pm
Forum: General discussion
Topic: PI4 identify 1,2 or 4GB version
Replies: 4
Views: 688

Re: PI4 identify 1,2 or 4GB version

Looking at the pi4 board itself, there's only the RAM chip number to go on:

Image

4GB : D9WHV (M - micron logo)

2GB: D9WHZ (M - micron logo)

1GB: 4HBMGCJ ( + QR code)
by mikerr
Fri Jun 28, 2019 2:21 pm
Forum: General discussion
Topic: Very simple OTG on pi4
Replies: 8
Views: 1045

Very simple OTG on pi4

I've found OTG is really simple and useful on the pi4 with new firmware. Since the USB-C power port can now carry data, you can plug that into a USB port on your PC and access the Pi via a drive letter. https://i.imgur.com/FxFQrybm.png https://i.imgur.com/vj802kAt.png Here's how: 1. Add a single lin...
by mikerr
Wed Jun 26, 2019 3:35 pm
Forum: General discussion
Topic: (again) Raspberry Pi sleep/standby modes software support
Replies: 8
Views: 533

Re: (again) Raspberry Pi sleep/standby modes software support

Some more info in this thread:
https://www.raspberrypi.org/forums/view ... 3&t=243421
but although the pi4 is better than previous models - it shuts down to 20 mA - there is no standby/sleep as yet.
by mikerr
Wed Jun 26, 2019 9:52 am
Forum: General discussion
Topic: Raspberry Pi 4 - Sleep Mode
Replies: 7
Views: 1256

Re: Raspberry Pi 4 - Sleep Mode

Other Pi models continue to draw a high ~100mA in shutdown/halt. There is a minor mod to the 3B+ to get 11mA in shutdown state https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=207961&p=1287499#p1286828 but that doesn't work on the 4B The 4B by default shuts down to a decent 20mA draw When the...
by mikerr
Tue Jun 25, 2019 4:06 pm
Forum: General discussion
Topic: A Pi Pie Chart
Replies: 111
Views: 9774

Re: A Pi Pie Chart

Asus Tinkerboard gcc --version gcc (Debian 6.3.0-18+deb9u1) 6.3.0 20170516 ./pichart-openmp -t "Asus Tinkerboard" pichart -- Raspberry Pi Performance OPENMP version 30 Prime Sieve P=14630843 Workers=4 Sec=0.907341 Mops=1029.74 Merge Sort N=16777216 Workers=8 Sec=0.80095 Mops=502.72 Fourier Transform...
by mikerr
Tue Jun 25, 2019 3:41 pm
Forum: General discussion
Topic: PI4 identify 1,2 or 4GB version
Replies: 4
Views: 688

Re: PI4 identify 1,2 or 4GB version

Oops on my 4GB pi 4B vcgencmd get_mem arm arm=948M So better use meminfo or free -h grep MemTotal /proc/meminfo MemTotal: 3999792 kB free -h total used free shared buff/cache available Mem: 3.8Gi 93Mi 3.6Gi 9.0Mi 100Mi 3.6Gi Swap: 99Mi 0B 99Mi
by mikerr
Tue Jun 25, 2019 2:55 pm
Forum: General discussion
Topic: A Pi Pie Chart
Replies: 111
Views: 9774

Re: A Pi Pie Chart

Pi4B results (Just with raspbian's preinstalled gcc) gcc --version gcc (Raspbian 8.3.0-6+rpi1) 8.3.0 make gcc -std=gnu99 -O3 -mtune=native -march=native -Wall -o pichart-serial pichart.c util.c sieve.c merge.c fourier.c lorenz.c -lm gcc -std=gnu99 -O3 -mtune=native -march=native -Wall -fopenmp -o pi...
by mikerr
Tue Jun 25, 2019 2:39 pm
Forum: General discussion
Topic: Pi4 Sysbench results
Replies: 1
Views: 490

Pi4 Sysbench results

I previously ran sysbench to compare Pi3B and Asus Tinkerboard, so added pi4 to the mix: sysbench --num-threads=4 --test=cpu --cpu-max-prime=20000 --validate run Number of threads: 4 Pi 3B total time: 129.6265s per-request statistics: min: 47.69ms avg: 48.12ms Asus Tinkerboard total time: 82.5418s p...
by mikerr
Tue Jun 25, 2019 12:07 pm
Forum: General discussion
Topic: Raspberry Pi 4 Thread - general discussion
Replies: 752
Views: 64362

Re: Raspberry Pi 4 Thread - general discussion

Have my hands on a pi4 now - yay ! So onto some quick power draw tests Idling on raspbian desktop: 562 mA 4 cores in use * 1005 mA Shutdown with sudo shutdown -h 20 mA *Quick way to busy the 4 cores: cat /dev/zero >/dev/null & cat /dev/zero >/dev/null & cat /dev/zero >/dev/null & cat /dev/zero >/dev...
by mikerr
Mon Jun 24, 2019 9:46 am
Forum: Teaching and learning resources
Topic: Scratch 3.0 please fix it NOW
Replies: 36
Views: 2374

Re: Scratch 3.0 please fix it NOW

Fixed in buster (and mods probably had to bite their tongue before release)
by mikerr
Mon Jun 24, 2019 9:23 am
Forum: General discussion
Topic: Raspberry Pi 4 Thread - general discussion
Replies: 752
Views: 64362

Re: Raspberry Pi 4 Thread - general discussion

Fantastic news, got my 4GB order in earlier ! Looks like everything I wanted is there: - Faster CPU - Proper gigabit ethernet - USB3 - Oodles of RAM - Buster Struggling to find minor cons, but: - No IR (but cheap to add on) - No SATA ( USB3 - SATA is cheap though) - Single CSI (so compute module sti...
by mikerr
Sat Jun 22, 2019 2:14 pm
Forum: Python
Topic: Pythonanywhere
Replies: 4
Views: 822

Mikerr

Yes it's great for non interactive / graphical stuff.

Also take a look at trinket.io if you want to use pygame in browser ( or tkinter with a subscription)
by mikerr
Sun Jun 16, 2019 11:18 am
Forum: Off topic discussion
Topic: how heavy is raspbian ?
Replies: 30
Views: 3673

Re: how heavy is raspbian ?

There is a bare desktop download if you don't want all the apps preinstalled, or even raspbian lite if you don't even want the desktop. Raspbian stretch full desktop & all apps: 2GB download, 5.6GB installed Raspbian stretch desktop: 1GB download, 3.4GB installed Raspbian Lite: 400MB download, 1.9GB...
by mikerr
Tue May 28, 2019 11:27 am
Forum: Raspberry Pi Desktop for PC and Mac
Topic: Debian x86 RPi Desktop and PiServer
Replies: 35
Views: 9382

Re: Debian x86 RPi Desktop and PiServer

Extract the boot & root filesystems from your premade .img : sudo kpartx -a yourOS.img mkdir boot root sudo mount /dev/mapper/loop0p1 boot sudo mount /dev/mapper/loop0p2 root sudo tar -C boot -cJf boot.xz . sudo tar -C root -cJf root.xz . Run those files through the piserver merger: piserver/scripts...
by mikerr
Sat Apr 27, 2019 11:12 pm
Forum: Raspberry Pi Desktop for PC and Mac
Topic: Brightness settings using GUI
Replies: 10
Views: 3902

Re: Brightness settings using GUI

Save it as brightness.py and run it with

Code: Select all

python brightness.py
by mikerr
Sun Apr 14, 2019 9:26 am
Forum: General discussion
Topic: how to change the logo boot ?
Replies: 15
Views: 1487

Re: how to change the logo boot ?

Replace the file /usr/share/plymouth/themes/pix/splash.png with your own (or just remove it for a blank screen)

Add logo.nologo to the end of the line in /boot/cmdline.txt to remove the four raspberries (on pi3)

Go to advanced search