Go to advanced search

by IanS
Thu Nov 11, 2021 10:16 am
Forum: Graphics, sound and multimedia
Topic: Stereo Video Output for VR
Replies: 1
Views: 112

Re: Stereo Video Output for VR

How about doing it the way that the Google Cardboard devices do it? Generate two viewpoints but display them on different halves of a single display.
by IanS
Tue Sep 28, 2021 1:32 pm
Forum: Graphics, sound and multimedia
Topic: Real-time sound play
Replies: 4
Views: 460

Re: Real-time sound play

Thanks Vanfanel, I'll look into that. My organ code dates from the Pi v2 period, and tweaking the audio buffers only took me so far. I use an external USB sound device, so it may not have been the Broadcom code, but the principle may still apply.
by IanS
Tue Sep 28, 2021 8:43 am
Forum: Graphics, sound and multimedia
Topic: Real-time sound play
Replies: 4
Views: 460

Re: Real-time sound play

It looks like omxplayer has a slow start up: pi@PiDev:~ $ time aplay /usr/share/sounds/alsa/Front_Center.wav Playing WAVE '/usr/share/sounds/alsa/Front_Center.wav' : Signed 16 bit Little Endian, Rate 48000 Hz, Mono real 0m1.641s user 0m0.033s sys 0m0.043s pi@PiDev:~ $ time omxplayer -o local /usr/sh...
by IanS
Mon Sep 27, 2021 10:59 am
Forum: Networking and servers
Topic: Fundamental Security questions
Replies: 27
Views: 1357

Re: Fundamental Security questions

Having a VPN server running on a Pi is a good way to have a gateway from external threats. It could be one of the coop ones or a new dedicated device. Depending on what sort of VPN you choose (e.g. OpenVPN, IPSec, Wireguard) you will need to forward one or more ports from the router to the gateway, ...
by IanS
Tue Sep 21, 2021 2:38 pm
Forum: Automation, sensing and robotics
Topic: Middle I/O board for Astro Pi
Replies: 0
Views: 273

Middle I/O board for Astro Pi

Does anybody have any suggestions for the middle I/O board in an Astro Pi? The real ones have a custom board so I am looking for something that can provide similar functionality - mainly a real time clock and GPIO pin access for the buttons and infrared presence sensor. One possibility is the Expand...
by IanS
Thu Sep 16, 2021 1:14 pm
Forum: General discussion
Topic: New ISS Pi in space, Pi4, new SenseHAT, HD camera, Corel and extra.
Replies: 21
Views: 1728

Re: New ISS Pi in space, Pi4, new SenseHAT, HD camera, Corel and extra.

The V2 Sense Hat will have to be released to the public. How else can kids code for the Astro Pi Challenge? An emulator, like there is for V1? I agree that allowing people to get their hands on them seems likely to happen, but that does not mean the availability is soon. Mind you, Raspberry Pi is n...
by IanS
Thu Sep 16, 2021 12:49 pm
Forum: General discussion
Topic: New ISS Pi in space, Pi4, new SenseHAT, HD camera, Corel and extra.
Replies: 21
Views: 1728

Re: New ISS Pi in space, Pi4, new SenseHAT, HD camera, Corel and extra.

Are there to be any confirmations/timelines provided for all the new goodies? e.g. Will SenseHat v2 be a commercially available product at some point, or is it just a one-off small run production for high altitude use only? Is there an expected target date for the case STL files? Next week? Next yea...
by IanS
Wed Sep 15, 2021 2:04 pm
Forum: General discussion
Topic: New ISS Pi in space, Pi4, new SenseHAT, HD camera, Corel and extra.
Replies: 21
Views: 1728

Re: New ISS Pi in space, Pi4, new SenseHAT, HD camera, Corel and extra.

Bensimmo, if you look at the disassembly video, https://astro-pi.org/assets/about/the_computer/exploding_diagram-9b5bd08db380d5ca03aaab10a1d048da20996d01d4f0f142be3e249c882488d85ed3e96a021a8c509b617e6ea81baf158821b93b801e7c80f33e2a91bfcab681.webm , at about 0:10 you can see a heat transfer component...
by IanS
Wed Aug 18, 2021 11:35 am
Forum: Automation, sensing and robotics
Topic: Proper connection of electrical robot components: RP + RP cam, Dynamixel servos, steppers + drivers, energy source(s)
Replies: 1
Views: 479

Re: Proper connection of electrical robot components: RP + RP cam, Dynamixel servos, steppers + drivers, energy source(s

You will need to look at what voltage each component requires (i.e. RPi 5V, dynamixel server 6-12V but 11.1V recommended, OpenCM9 5V, stepper motors probably 12V minimum or more for NEMA23 or larger). You will probably end up with at least 2 power supplies e.g. 12V and 5V, but might be able to use a...
by IanS
Mon Jul 19, 2021 3:38 pm
Forum: Advanced users
Topic: Is it possible to modulate the power through a relay at 70hz?
Replies: 6
Views: 569

Re: Is it possible to modulate the power through a relay at 70hz?

At that kind of rate you may be better using a transistor (probably a MOSFET) instead of a relay.
by IanS
Thu Apr 15, 2021 12:33 pm
Forum: Networking and servers
Topic: Which power supply to power 10 Raspberry
Replies: 4
Views: 393

Re: Which power supply to power 10 Raspberry

I have never tried power 10 RPis at once, but I have powered a few at once that had additional boards attached via GPIO that needed power as well, as the Pi could not provide enough via the 5V lines. I used one of these https://www.ebay.co.uk/itm/Regulated-Switching-Power-Supply-3-3V-5V-9V-12V-18V-2...
by IanS
Mon Mar 22, 2021 12:10 pm
Forum: Automation, sensing and robotics
Topic: Blind tilt automation
Replies: 2
Views: 483

Re: Blind tilt automation

It would help if you described how the blinds are tilted. Some blinds need a rod to be twisted, but others have a cord loop which needs to be pulled.
by IanS
Mon Mar 22, 2021 12:06 pm
Forum: Automation, sensing and robotics
Topic: Speedcontrol Nema 23
Replies: 9
Views: 782

Re: Speedcontrol Nema 23

As a very brief overview, you can control a small stepper motor through controlling 4 GPIO pins going through an amplifier to the 4 wires on the motor, such as described at https://lastminuteengineers.com/28byj48-stepper-motor-arduino-tutorial/ . Stepper motors can have 4, 6 or 8 wires depending on ...
by IanS
Wed Mar 17, 2021 9:57 am
Forum: Networking and servers
Topic: Use RasPi to notify me when someone new connects to network. Possible?
Replies: 2
Views: 350

Re: Use RasPi to notify me when someone new connects to network. Possible?

There are a number of ways to detect a new device on the local network, both active and passive. Detecting something in a different subnet generally requires active probing. One way is to put the network interface in promiscuous mode and look at all the traffic. When you see something like a DHCP re...
by IanS
Thu Mar 04, 2021 11:58 am
Forum: Off topic discussion
Topic: 3D Printing  [obsolete]
Replies: 4
Views: 2541

Re: 3D Printing

Thingiverse seems OK to me. The search engine does go a bit funny from time to time, returning no results for any search, but it normally recovers after a while.
by IanS
Thu Mar 04, 2021 11:47 am
Forum: Advanced users
Topic: Raspberry Pi at -50'C Celsius
Replies: 11
Views: 1096

Re: Raspberry Pi at -50'C Celsius

I once saw a demonstration of an active radio dipped into liquid nitrogen. It went quiet as all the semiconductors stopped working, then came back to life when it warmed up. Anything running an operating system and filesystem might not restart quite so cleanly though.
by IanS
Mon Feb 08, 2021 4:34 pm
Forum: Graphics, sound and multimedia
Topic: Fluidsynth privileges
Replies: 3
Views: 2524

Re: Fluidsynth privileges

Thanks very much.
This is still relevent to the original project, although next time I update that particular system the change from ALSA to PulseAudio might add additional complications.
by IanS
Wed Feb 03, 2021 10:02 am
Forum: Automation, sensing and robotics
Topic: Stepper Motor with Brake
Replies: 7
Views: 581

Re: Stepper Motor with Brake

Use a proper stepper driver board, as has already been mentioned. If you use an H-bridge style module you will need a lot of GPIO pins and will have no control over the current going through the motor. A proper driver just needs step and direction pins and looks after the current for you. If you use...
by IanS
Mon Feb 01, 2021 11:24 am
Forum: Advanced users
Topic: Maximum Frame rate By Raspberry Pi High-quality Camera (IMX477)
Replies: 3
Views: 710

Re: Maximum Frame rate By Raspberry Pi High-quality Camera (IMX477)

You do not say what you are taking a video of, but is a non-computing solution possible? e.g. Shine an extra light on the subject?
by IanS
Tue Jan 12, 2021 10:47 am
Forum: Other projects
Topic: Patients records
Replies: 2
Views: 281

Re: Patients records

A quick search on-line brings up an easy to find list: https://www.goodfirms.co/blog/best-free-open-source-Electronic-Medical-Records-software-solutions . You do not say where you are operating in the original post (second poster is from Germany), but most countries have strict privacy laws around m...
by IanS
Tue Dec 08, 2020 4:21 pm
Forum: Advanced users
Topic: Please tell me whether your wifi chip supports MFP/802.11w by running a simple command
Replies: 5
Views: 538

Re: Please tell me whether your wifi chip supports MFP/802.11w by running a simple command

Hardware : BCM2835 Revision : 9000c1 Serial : 00000000232a6f89 Model : Raspberry Pi Zero W Rev 1.1 $ iw phy | grep -A9 "Supported Ciphers" Supported Ciphers: * WEP40 (00-0f-ac:1) * WEP104 (00-0f-ac:5) * TKIP (00-0f-ac:2) * CCMP-128 (00-0f-ac:4) Available Antennas: TX 0 RX 0 Supported inte...
by IanS
Tue Dec 08, 2020 4:16 pm
Forum: Advanced users
Topic: Please tell me whether your wifi chip supports MFP/802.11w by running a simple command
Replies: 5
Views: 538

Re: Please tell me whether your wifi chip supports MFP/802.11w by running a simple command

Hardware : BCM2835 Revision : a02082 Model : Raspberry Pi 3 Model B Rev 1.2 $ iw phy | grep -A9 "Supported Ciphers" Supported Ciphers: * WEP40 (00-0f-ac:1) * WEP104 (00-0f-ac:5) * TKIP (00-0f-ac:2) * CCMP-128 (00-0f-ac:4) Available Antennas: TX 0 RX 0 Supported interface modes: * IBSS * m...
by IanS
Mon Dec 07, 2020 2:46 pm
Forum: Gaming
Topic: Retro Pi 4 arcade cabinet sub $100 budget
Replies: 2
Views: 455

Re: Retro Pi 4 arcade cabinet sub $100 budget

Depends on whether that $100 is just the cabinet or the full costs. There are plenty of plans available for full size cabinets that can be made from two sheets of 3/4" MDF, which will be about half that budget. Add another $25 for various fixings to hold the thing together. However, by the time...
by IanS
Mon Dec 07, 2020 1:57 pm
Forum: Other projects
Topic: Mounting a Pi onto wood
Replies: 9
Views: 909

Re: Mounting a Pi onto wood

Use M3 or M2.5 standoffs. Previous posters have already mentioned using M3, but I prefer M2.5 - it gives you just a bit more scope for drilling a hole slightly out of position if you are drilling by hand. I have mounted quite a few PIs onto MDF this way, which are then given high processing loads, a...
by IanS
Fri Nov 27, 2020 9:53 am
Forum: Graphics, sound and multimedia
Topic: Low Latency audio ? pisound ?
Replies: 3
Views: 1585

Re: Low Latency audio ? pisound ?

You do not say what kind of audio you are dealing with. The solution could vary. Are you e.g. receiving MIDI inputs and synthesizing the output? Receiving, processing and outputing audio signals? Generating audio purely internally and outputing it? What is your audio processing framework - ALSA or p...

Go to advanced search