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by PiGraham
Fri May 04, 2018 7:56 am
Forum: General discussion
Topic: Tricorder
Replies: 2
Views: 138

Re: Tricorder

Tricorders are quite popular Pi projects. Here's one built into what looks like the same toy case but using a Pi Zero and a Sense HAT. https://blog.hackster.io/toy-star-trek-tricorder-turned-into-the-real-thing-bf7fc1c0f28f http://www.tricorderproject.org/ And Recantha's more functional approach was...
by PiGraham
Fri May 04, 2018 7:39 am
Forum: General discussion
Topic: Tricorder
Replies: 2
Views: 138

Re: Tricorder

I was surprised to see the PP3 9V battery in there. It doesn't seem like the best power option. A mini USB LiPo power pack ought to fit.
by PiGraham
Fri May 04, 2018 7:32 am
Forum: Advanced users
Topic: USB/ETH Hub burnt pin
Replies: 6
Views: 291

Re: Video chip burnt pin

That looks more like flux on top of the solder than damage. If the Pi is working I suggest you ignore it.
by PiGraham
Thu May 03, 2018 8:21 am
Forum: General discussion
Topic: Tricorder
Replies: 2
Views: 138

Tricorder

Based on a Raspberry Pi At this year's Replica Prop Forum showcase, we meet up once again wtih Brian Mix, who brought his new Star Trek TOS Tricorder. This beautiful replica captures the weight and finish of the filming hand prop, and Brian has taken it one step further with some modern-day electron...
by PiGraham
Wed May 02, 2018 12:43 pm
Forum: Networking and servers
Topic: Connect more than eight USB drives?
Replies: 6
Views: 277

Re: Connect more than eight USB drives?

Does the number of active devices / bus activity make a difference here? If many devices are plugged in but not being used (e.g. unmounted drive) does that allow more devices than if they are active? If that were the case could a larger number of drives be used if you only mount the drive you need t...
by PiGraham
Tue May 01, 2018 2:40 pm
Forum: Camera board
Topic: Multiple cameras on a single raspberry pi board
Replies: 63
Views: 119637

Re: Multiple cameras on a single raspberry pi board

I beleive this is the solution you are looking for: https://www.amazon.com/Arducam-Camera-Adapter-Compatible-Raspberry/dp/B012UQWOOQ Its a multicamera adaptor. You can extend this module so that you would connect more and more cameras to your single Pi through MIPI. That's the same board that has a...
by PiGraham
Tue May 01, 2018 10:23 am
Forum: Beginners
Topic: Low-power photo uploader
Replies: 1
Views: 75

Re: Low-power photo uploader

Raspberry Pi doesn't really have a low power mode. To get best battery life use a low power microcontroller to power up the Pi when needed For what you describe you might be better to use an ESP32 which can enter sleep mode that uses only microamps, has WiFi and can talk to internet servers. However...
by PiGraham
Tue May 01, 2018 10:08 am
Forum: Other projects
Topic: Building Precision Clocks Using the RaspberryPi
Replies: 4
Views: 236

Re: Building Precision Clocks Using the RaspberryPi

Although that is interesting and very functional I must admit to being a little disappointed that these were not more sculptural. I was hoping to see something that resembled an hourglass or an obelisk or some antique timepiece running with atomic precision.
by PiGraham
Tue May 01, 2018 7:53 am
Forum: Other projects
Topic: Connecting multiple cameras to one raspi?
Replies: 6
Views: 306

Re: Connecting multiple cameras to one raspi?

Given the references in the OP to Nishika N8000 and cheap webcams the best option for simultaneous capture is probably to view four optical paths with a single camera. An 8MP Pi camera will give better quality that N8000 lenses can deliver and better than four cheap webcams.
by PiGraham
Tue May 01, 2018 7:50 am
Forum: Other projects
Topic: Connecting multiple cameras to one raspi?
Replies: 6
Views: 306

Re: Connecting multiple cameras to one raspi?

Gavinmc42 wrote:
Tue May 01, 2018 12:39 am
Use 4 Zero's or two CMs

Clusterhat can hold 4 Zeros.
https://clusterhat.com/
One Pi per camera is an option to provide storage for each camera, although note that the sensors cannot be precisely synchronised There could be positional differences between views where there is fast motion.
by PiGraham
Tue May 01, 2018 7:46 am
Forum: Advanced users
Topic: Using OpenNI2 or OpenCV to find human in room?
Replies: 3
Views: 107

Re: Using OpenNI2 or OpenCV to find human in room?

This sounds like a difficult problem where common and easy approaches won't work. I suggest you look at Tensor Flow and deep learning. Show a neural network lots of images of human bodies and scenes without bodies covering as much variation as possible. You should consider how important it is to rep...
by PiGraham
Mon Apr 30, 2018 7:31 pm
Forum: Other projects
Topic: Connecting multiple cameras to one raspi?
Replies: 6
Views: 306

Re: Connecting multiple cameras to one raspi?

It would be ideal if the pi could take the 4 photos with the 4 cameras at exactly the same time, so the only thing that is different between the pictures, is the positioning of the cameras As I said, you can't do that unless you use cameras with internal buffers, and those are expensive industrial ...
by PiGraham
Sat Apr 28, 2018 7:21 pm
Forum: Beginners
Topic: Raspi powered by car battery
Replies: 8
Views: 226

Re: Raspi powered by car battery

I apprciate all your comments but it still does'nt give me a clou about the problem i face. I think KLL and drgeoff identified the problem. At 40 °C/W and at least 3.5W (12-5=7V x 500mA) dissipation the junction temp in that regulator will be hitting 3.5 x 40 = 140+°C and triggering thermal protect...
by PiGraham
Sat Apr 28, 2018 5:58 pm
Forum: Beginners
Topic: Raspi powered by car battery
Replies: 8
Views: 226

Re: Raspi powered by car battery

You should use a switch mode buck converter. Linear regulators with big voltage differentials waste a lot of energy and get hot.
by PiGraham
Sat Apr 28, 2018 12:11 pm
Forum: C/C++
Topic: Cross Compile and remote debug
Replies: 5
Views: 484

Re: Cross Compile and remote debug

Any advice on what setup would work best for a touch screen graphics program on a secondary LCD and FB not running Xterm? It seams the built in QT supports on VisualGDB is for Xterm. GTK or SDL may be better, a newbie like me does still has so much reading to do. I developed an SDL2 application wit...
by PiGraham
Fri Apr 27, 2018 4:29 pm
Forum: General discussion
Topic: multiplayer games for kids in a LAN
Replies: 3
Views: 135

Re: multiplayer games for kids in a LAN

You may discover something interesting. in the repository although it is a mixed bag. Start...Preferences...Add/remove software and search Or use the command line apt-cache search "multiplayer", "racing" etc FreeCiv is on there which has a LAN multiplayer mode I have seen good reports on, but that m...
by PiGraham
Fri Apr 27, 2018 2:07 pm
Forum: Automation, sensing and robotics
Topic: Finding a sensor to log shock travel on a vehicle
Replies: 8
Views: 403

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

By the wonders of Internet serendipity, a few days later and this post pops up from someone who has done something similar to what you are asking about: https://www.raspberrypi.org/forums/viewtopic.php?f=37&t=212152#p1308559 That's interesting. I see mention of "linear potentiometers attached to sh...
by PiGraham
Fri Apr 27, 2018 10:47 am
Forum: Python
Topic: Controlling 2 stepper motors with 2 ULN2003
Replies: 10
Views: 4695

Re: Controlling 2 stepper motors with 2 ULN2003

The ULN2003 isn't a driver chip, it's a buffer chip (it only prevents back EMF). Think again. Actually it's a darlington array commonly supplied with cheap unipolar stepper motors. The switch higher currents and voltages when driven with very low current an voltage from gpio pins. They also have fl...
by PiGraham
Fri Apr 27, 2018 10:34 am
Forum: Python
Topic: Python code only lets servos turn once
Replies: 10
Views: 313

Re: Python code only lets servos turn once

I have only one question - if I do not type in "r" or "l" I can see and hear the servos buzzing and trying to move even though the code does not require them to do so. Why is this happening? I know the one person here said that the servos "have reached their internal limit" - how do I stop them fro...
by PiGraham
Thu Apr 26, 2018 8:20 pm
Forum: Beginners
Topic: Cheapest possible off-grid GSM CCTV
Replies: 8
Views: 207

Re: Cheapest possible off-grid GSM CCTV

My first thought was a 'trail cam', or several. They don't connect to 4G/LTE but if you visit the site every couple of days and you want evidence of who rather than instant response that might be good enough. They run on battery for a long time, are weather proof and have IR lighting built in if you...
by PiGraham
Thu Apr 26, 2018 5:12 pm
Forum: Beginners
Topic: Ipad to TV through RPi (Ipad-wifi-Rpi-HDMI-TV)
Replies: 17
Views: 302

Re: Ipad to TV through RPi (Ipad-wifi-Rpi-HDMI-TV)

Raspomain wrote:
Thu Apr 26, 2018 3:59 pm
I posted a message in the Kodi forum.
Airplay doesn't work anymore with Kodi for Apple introduced DRM to the video stream ...
I hate this firm. So it appears the only way is to buy an Apple TV (or use the HDMI adapter) ...
Ah, sorry to hear that. I only knew there was an option in there.
by PiGraham
Thu Apr 26, 2018 12:34 pm
Forum: C/C++
Topic: Cross Compile and remote debug
Replies: 5
Views: 484

Re: Cross Compile and remote debug

Development on the target is definitely viable.
I use VisualGDB for one Pi project. It's a plugin for Visual Studio and gives you the usual intellisense and debug environment. It configures a cross platform build toolchain. Fairly easy and effective.
by PiGraham
Thu Apr 26, 2018 10:07 am
Forum: Beginners
Topic: Ipad to TV through RPi (Ipad-wifi-Rpi-HDMI-TV)
Replies: 17
Views: 302

Re: Ipad to TV through RPi (Ipad-wifi-Rpi-HDMI-TV)

Thank you. I am using a bluetooth keyboard :) Now my iPad can see Kodi. But I still don't know how to stream the iPad display. Did you follow the video ? Have you used Airplay before? I don't know Apple so I can't help you more on that. Basically enable Airplay on Kodi and connect your Apple device...
by PiGraham
Thu Apr 26, 2018 9:14 am
Forum: Beginners
Topic: Ipad to TV through RPi (Ipad-wifi-Rpi-HDMI-TV)
Replies: 17
Views: 302

Re: Ipad to TV through RPi (Ipad-wifi-Rpi-HDMI-TV)

Kodi displays on HDMI (primary display, HDMI, DSI, composite, not VNC), which is what you said you wanted to do.

You can control Kodi using remote apps or web interface
e.g. https://itunes.apple.com/gb/app/officia ... 80364?mt=8
by PiGraham
Thu Apr 26, 2018 8:14 am
Forum: Other projects
Topic: Connecting multiple cameras to one raspi?
Replies: 6
Views: 306

Re: Connecting multiple cameras to one raspi?

If you really need it simultaneous you might be able to combine more than one view into one camera. This site describes ways to do that with two views: https://www.lockhaven.edu/~dsimanek/3d/stereo/3dgallery16.htm It gets even more complicated with more than two. You can use two USB webcams almost s...

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