Go to advanced search

by PiGraham
Mon Apr 23, 2018 3:48 pm
Forum: Gaming
Topic: Running Half-Life on Raspberry Pi?
Replies: 5
Views: 189

Re: Running Half-Life on Raspberry Pi?

rpiMike wrote:
Mon Apr 23, 2018 3:20 pm
Looks like it is possible with Exagear:

https://www.youtube.com/watch?v=A2_ZEo9N_fM
That would not be an enjoyable gaming experience.
by PiGraham
Mon Apr 23, 2018 2:47 pm
Forum: Troubleshooting
Topic: PiCamera preview in high resolution
Replies: 5
Views: 121

Re: PiCamera preview in high resolution

AH, I may have missed the key info there. You can run full HD OK in all configurations except when raspi2raspi is running? If raspi2raspi is using GPU to scale the image, as seems likely, then there is a heavy load on the GPU to support full display and camera and mirror to 7". Maybe you are running...
by PiGraham
Mon Apr 23, 2018 12:44 pm
Forum: Graphics, sound and multimedia
Topic: A "simple" instrument
Replies: 12
Views: 158

Re: A "simple" instrument

There seems to be a bit of conflict between "simple" and the level of control you want. How about http://zynthian.org/ with Dexed FM synth plugin? It looks like you can add as much complexity and control as you like. Well, I thought it was simple. I basically only want to be able to play a sine wav...
by PiGraham
Mon Apr 23, 2018 12:26 pm
Forum: Troubleshooting
Topic: PiCamera preview in high resolution
Replies: 5
Views: 121

Re: PiCamera preview in high resolution

I use raspi2raspi from Andrew to mirror the screen from the 7" primary screen to the HDMI. It works well. Shouldn't you be mirroring the HDMI to the TFT? Then the HD preview will naturally be HD and the small display will get a scaled-down copy. Going the other way surely scales-up a low res image ...
by PiGraham
Mon Apr 23, 2018 8:34 am
Forum: Graphics, sound and multimedia
Topic: A "simple" instrument
Replies: 12
Views: 158

Re: A "simple" instrument

kirre wrote:
Sun Apr 22, 2018 9:36 pm
Next thing is, i want to have five knobs on the box that I'll build that control Attack, Release, Time and Feedback (on the delay), and a volume knob.

Is that a reverb? You want to control it per note?
by PiGraham
Mon Apr 23, 2018 8:30 am
Forum: Graphics, sound and multimedia
Topic: A "simple" instrument
Replies: 12
Views: 158

Re: A "simple" instrument

There seems to be a bit of conflict between "simple" and the level of control you want.
How about

http://zynthian.org/ with Dexed FM synth plugin?

It looks like you can add as much complexity and control as you like.
by PiGraham
Fri Apr 20, 2018 9:16 pm
Forum: General discussion
Topic: IoT based Attendance Recording System
Replies: 22
Views: 450

Re: IoT based Attendance Recording System

Has anyone got experience of a system that worked well? I would say most systems work well but it depends on what one is intending to achieve, how one defines 'well', and how much abuse will be tolerated. Good point. I guess the objective is to improve on the fingerprint system and minimise error a...
by PiGraham
Fri Apr 20, 2018 4:28 pm
Forum: General discussion
Topic: IoT based Attendance Recording System
Replies: 22
Views: 450

Re: IoT based Attendance Recording System

It has to be iris scanners as shown in Minority Report.

Well, that or the spiders!
by PiGraham
Fri Apr 20, 2018 3:56 pm
Forum: General discussion
Topic: IoT based Attendance Recording System
Replies: 22
Views: 450

Re: IoT based Attendance Recording System

What I never really get is why we need an in and an out RFID sensor (or in your case or in/out for finger prints). If you swipe and the time has been long enough, you are then not what you where before ? Otherwise why swipe. Thing is students could turn up at the door twice a day just to swipe the ...
by PiGraham
Fri Apr 20, 2018 3:52 pm
Forum: General discussion
Topic: IoT based Attendance Recording System
Replies: 22
Views: 450

Re: IoT based Attendance Recording System

Has anyone got experience of a system that worked well?
by PiGraham
Fri Apr 20, 2018 11:25 am
Forum: Automation, sensing and robotics
Topic: Automated mower for a large yard
Replies: 10
Views: 5110

Re: Automated mower for a large yard

Petrol or electric? For a DIY effort I would assume electric motor and battery power for ease of control. That also allows autonomous refueling which I think is far too dangrous to do with petrol.
by PiGraham
Fri Apr 20, 2018 9:11 am
Forum: Automation, sensing and robotics
Topic: Automated mower for a large yard
Replies: 10
Views: 5110

Re: Automated mower for a large yard

Why not start with an actual lawn mower and robotize it?
That gives you a sturdy structure with safety cowl, cut height adjustment and grass collection. Replace wheels / roller with steering / powered wheels. Add sensors and control system
by PiGraham
Fri Apr 20, 2018 9:05 am
Forum: General discussion
Topic: IoT based Attendance Recording System
Replies: 22
Views: 450

Re: IoT based Attendance Recording System

I assume that almost all students carry a Wi-Fi or Bluetooth enabled device around campus. If those radios are on they can be tracked. https://www.crc.id.au/tracking-people-via-wifi-even-when-not-connected/ Of course there are various ways in which that can be defeated, from turning the radios off t...
by PiGraham
Fri Apr 20, 2018 8:37 am
Forum: General discussion
Topic: IoT based Attendance Recording System
Replies: 22
Views: 450

Re: IoT based Attendance Recording System

What is the purpose of the system, to count who turns up at the gate? To check that students are on campus during the day? To know how many people are on site? Is it supposed to relate in some way to attendance in classes? It might be in students' interests to defeat such a system by logging high nu...
by PiGraham
Fri Apr 20, 2018 7:37 am
Forum: General discussion
Topic: IoT based Attendance Recording System
Replies: 22
Views: 450

Re: IoT based Attendance Recording System

Heater wrote:
Fri Apr 20, 2018 6:46 am
I'm curious. Why is there a need to know if students are coming in or going out? Or that they are there at all?

During all my years in Technical College, then University, nobody was continuously, intrusively, monitoring our attendance.
Good point
by PiGraham
Thu Apr 19, 2018 7:46 pm
Forum: Other languages
Topic: How do I compile a Visual Basic program for the Pi?
Replies: 7
Views: 210

Re: How do I compile a Visual Basic program for the Pi?

I'm not sure of the details but Mono on Linux allows you to run dotnet CLR programs but visual basic support may be lacking on Raspbian

http://www.mono-project.com/docs/about- ... sualbasic/

https://stackoverflow.com/questions/477 ... spberry-pi
by PiGraham
Thu Apr 19, 2018 6:20 pm
Forum: Python
Topic: Pushbutton controlling multiple LED's
Replies: 3
Views: 77

Re: Pushbutton controlling multiple LED's

Note that gpiozero has when_held events for buttons in addition to WhenPressed so you could do both functions with one button if you like. The WhenPressed function increments the count to light LEDs and a long hold on the button does the reset. You could consider using a strip of "neopixels" (WS2812...
by PiGraham
Thu Apr 19, 2018 2:55 pm
Forum: General discussion
Topic: IoT based Attendance Recording System
Replies: 22
Views: 450

Re: IoT based Attendance Recording System

Can you make an IN and an OUT lane each with a reader?

If you could find a long range reader you could arrange two of those at every entry/exit, call them A and B, then a read of IDx at A then B is entry and B then A is exit.
by PiGraham
Thu Apr 19, 2018 2:24 pm
Forum: General discussion
Topic: IoT based Attendance Recording System
Replies: 22
Views: 450

Re: IoT based Attendance Recording System

How do you ID the students? RFID would be easy to implement, tags are cheap and most could probably use NFC in their phones. Bluetooth proximity is another option using phones but BT may not be active. . Facial recognition is the obvious choice but not 100% reliable. How reliable do you need it to b...
by PiGraham
Thu Apr 19, 2018 12:48 pm
Forum: Automation, sensing and robotics
Topic: What Optical Sensors for Archery?
Replies: 3
Views: 88

Re: What Optical Sensors for Archery?

That sounds challenging. My initial thoughts are: 1. Use a Pi camera to look across the face of the board at a difuse light on the other side and mount these on a rotating arm so that you can get multiple views of the arrows from all sides. This could involve some tricky maths. It has a lot in commo...
by PiGraham
Thu Apr 19, 2018 11:14 am
Forum: Automation, sensing and robotics
Topic: Finding a sensor to log shock travel on a vehicle
Replies: 5
Views: 189

Re: Finding a sensor to log shock travel on a vehicle

You want to measure how far car shock absorbers move? Sombeody posted on this forum a few days ago mentioning a type of sensor I hadn't heard of before. I can't find that post, but one name for these sensors is "cable extension transducer". Some expensive looking examples are here https://www.varioh...
by PiGraham
Thu Apr 19, 2018 10:40 am
Forum: Raspbian
Topic: Pi 3B+ 2.4ghz works but not 5ghz wifi
Replies: 5
Views: 225

Re: Pi 3B+ 2.4ghz works but not 5ghz wifi

You could check that the channel rou router is using is within the range your Pi is open to. I think that is controlled by region codes on both devices but check the channel number. If you can connect to the router from a Windows PC you can see the channel in use on the properties of the network. I ...
by PiGraham
Thu Apr 19, 2018 7:34 am
Forum: Advanced users
Topic: Syncing a high power LED array to camera start frame.
Replies: 32
Views: 748

Re: Syncing a high power LED array to camera start frame.

You have a strange attitude. If you did want to use a DSLR take a look at gphoto2 which should allow you to download images as they are taken using USB. Since the issues discussed relate to the sensor changing to another SBC will make no difference. And to reiterate, you can use rolling shutter sens...
by PiGraham
Wed Apr 18, 2018 2:26 pm
Forum: Troubleshooting
Topic: add delay raspivid
Replies: 10
Views: 204

Re: add delay raspivid

Could a fifo buffer be used to queue 10 seconds of video through stdout? Hmm, that might work as well, although not sure how you would introduce a delay, apart from maybe starting the receiving end of FIFO later. It was just a thought. I suppose that if the proper frame rate is defined, rather that...

Go to advanced search