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by W. H. Heydt
Wed Jul 18, 2018 1:58 am
Forum: Beginners
Topic: Rasberry pi 3 b+ battery
Replies: 6
Views: 153

Re: Rasberry pi 3 b+ battery

There is no current battery technology that can run a Raspberry Pi for two weeks, without charging it. Get a solar setup, and prepare for some learning. Sure there is...a bank of Lead Acid batteries. Preferably "deep discharge" marine batteries. Not very portable, I'll grant you, but it could be do...
by W. H. Heydt
Tue Jul 17, 2018 6:23 pm
Forum: General discussion
Topic: Free Fall detection through Accelerometer using raspberry pi
Replies: 9
Views: 227

Re: Free Fall detection through Accelerometer using raspberry pi

Yeah, that as well. Also if your object is spinning whilst free falling and the accelerometer is not exactly at the center of mass of the object it will read some acceleration due to centrifugal force. Centripetal force, actually. But hey, let's start from basics. Yes...apply the old programming tr...
by W. H. Heydt
Tue Jul 17, 2018 5:24 pm
Forum: General discussion
Topic: Free Fall detection through Accelerometer using raspberry pi
Replies: 9
Views: 227

Re: Free Fall detection through Accelerometer using raspberry pi

Plus a small acceleration caused by drag from air.... (For true zero g, you need to be in a vacuum. Being on the ISS counts as being in a vacuum for this purpose. There is an exception for powered flight designed to counteract the air drag, as practiced by the Vomit Comet.)
by W. H. Heydt
Tue Jul 17, 2018 5:20 pm
Forum: General discussion
Topic: "Low depth" power supply
Replies: 9
Views: 245

Re: "Low depth" power supply

Thanks Mortimer - that is indeed my fall back option. I’d just like to reduce wire clutter as much as possible and try and keep things a bit tidier, even if it will be out of sight :) Cable ties to keep things neat. In the US, I can get extension cords with flat plugs that stick out about 1/4". One...
by W. H. Heydt
Mon Jul 16, 2018 2:04 am
Forum: General discussion
Topic: A Case for RPi
Replies: 8
Views: 332

Re: A Case for RPi

Patents apply to processes, there are also copyrights for images and trade marks. Both patents and copyrights can have a limited lifetime, but trade marks can live forever. Since Nintendo is still an ongoing concern I would try not to infringe on their images or trademarks. If you are selling a pro...
by W. H. Heydt
Sun Jul 15, 2018 10:28 pm
Forum: Beginners
Topic: How to restore rewritten version of CSV file?
Replies: 11
Views: 248

Re: How to restore rewritten version of CSV file?

Thank you all, good people! For the testing - I intentionally use 'w' mode of writing files. Don't need appending etc. No matter how careful you are, it may happen to everyone. Regards! In that case.... I would recommend wrapping your program in a shell script (if it isn't already) and including a ...
by W. H. Heydt
Sun Jul 15, 2018 8:34 pm
Forum: Beginners
Topic: connecting wi fi mouse to raspberry pi
Replies: 6
Views: 147

Re: connecting wi fi mouse to raspberry pi

First...I'm inclined to doubt that they use WiFi (IEEE 802.11x). Rather they almost certainly use Bluetooth (BT). Second, without a specifc model for the mouse and keyboard, it will be very difficult for anyone to give you more than the sketchiest and most general advice. About all I can say at this...
by W. H. Heydt
Sun Jul 15, 2018 8:30 pm
Forum: Beginners
Topic: A guide for actually programming on the pi
Replies: 7
Views: 235

Re: A guide for actually programming on the pi

Any book on the programming language you are interested in should work. It will help if it mentions running the language processor on Linux (wince that's what Raspbian is). Beyond that, to learn to program it doesn't really matter what hardware you're using. The only other issue might be if what you...
by W. H. Heydt
Sun Jul 15, 2018 3:44 pm
Forum: Beginners
Topic: How to restore rewritten version of CSV file?
Replies: 11
Views: 248

Re: How to restore rewritten version of CSV file?

I really hate to have to say this, but this is a prime example of what testing is all about. Had the process been tested, the problem would have been uncovered--and fixed--before going "live".
by W. H. Heydt
Sun Jul 15, 2018 3:41 pm
Forum: General discussion
Topic: Which pi to buy
Replies: 3
Views: 254

Re: Which pi to buy

If I were doing the project I would buy a used boom box from the thrift store, hook the existing analogue controls up to the Pi and the Pi sound output to the speakers. The Pi has a built-in line-level audio output which would be reasonable pass through the amplifier already in the boom box. That w...
by W. H. Heydt
Sat Jul 14, 2018 4:12 pm
Forum: Automation, sensing and robotics
Topic: Switching ON/OFF High Current Load
Replies: 13
Views: 352

Re: Switching ON/OFF High Current Load

Hmmm.... High current... Lawrence Berkeley Lab used to have to notify the local electric utility before switching on or off the magnet for the 188-inch cyclortron. The room between the poles was about 30 feet across, 6 feet high, and had a constant 37.5 Kgauss feild.... They also had to notify the F...
by W. H. Heydt
Sat Jul 14, 2018 4:03 pm
Forum: Networking and servers
Topic: Communication over ethernet cable between multiple pi's
Replies: 6
Views: 200

Re: Communication over ethernet cable between multiple pi's

If you don;t want to assign each Pi with a static IP address, you can configure one of them as a DHCP server. You don't have to limit yourself to a 4-port switch--which doesn't generally exist, since the smallest switches one generally finds are 5-port (so you get 4 working ports plus and uplink por...
by W. H. Heydt
Fri Jul 13, 2018 9:08 pm
Forum: Troubleshooting
Topic: Deleted Content
Replies: 2
Views: 128

Re: Deleted Content

You will need either another system to download and re-flash your SD card, or another card wtih Raspbian loaded on it. When you deleted Raspbian, you deleted the operating system. There is no longer anything to boot TO on that card. If you don't have a networked PC (or other system) available, check...
by W. H. Heydt
Fri Jul 13, 2018 9:05 pm
Forum: General discussion
Topic: Problem with connecting raspberry to Linux
Replies: 28
Views: 622

Re: Problem with connecting raspberry to Linux

Reading all the responses, I think the simplest (and quite possibly cheapest) solution is to buy: 1. 5-port Ethernet switch 2. 2 additional Ethernet cables. Connect the switch the existing Ethernet cable (the uplink), then use the two new cables to connect the laptop and the Pi to ports on the switc...
by W. H. Heydt
Fri Jul 13, 2018 7:30 pm
Forum: Beginners
Topic: Send Command from Raspberry Pi Zero to USB C
Replies: 6
Views: 140

Re: Send Command from Raspberry Pi Zero to USB C

So I guess the choice of a PiZero is about size and not about the fact its the only model that can do "slave-mode". Even ignoring the trivial case of the Pi0W, that's not correct. The A+ can be set to be a slave device. In addition, you program the on-board eMMC flash memory of a CM or CM3 by runni...
by W. H. Heydt
Fri Jul 13, 2018 3:59 pm
Forum: Beginners
Topic: HDMI problem
Replies: 6
Views: 171

Re: HDMI problem

I love asking stupid questions....because I make stupid mistakes and if I ask them of myself, I can make fewer of them....

Is the TV on and set to the correct input *before* you apply power to the Pi?
by W. H. Heydt
Fri Jul 13, 2018 3:56 pm
Forum: Beginners
Topic: Send Command from Raspberry Pi Zero to USB C
Replies: 6
Views: 140

Re: Send Command from Raspberry Pi Zero to USB C

USB-C is just a connector. USB communication protocols are supposed to be backwards compatible, so the USB 2.0 on the Pi should be able to connect to your camera's USB-whatever. The bigger issue is that USB is designed to run in a master-slave arrangement. The Pi generally defaults to master (that c...
by W. H. Heydt
Fri Jul 13, 2018 12:14 am
Forum: General discussion
Topic: Which pi to buy
Replies: 3
Views: 254

Re: Which pi to buy

Welcome to the forums. When starting out, get the current top Pi. As I write this, that would be the Pi3B+. After you figure out how to get everything working the way you want, start looking at things like power requirements, battery capacity, and desired run time. From that, decide if you want to u...
by W. H. Heydt
Fri Jul 13, 2018 12:08 am
Forum: General discussion
Topic: Is there a way to connect 2 RPi's to make a functional computer?
Replies: 15
Views: 660

Re: Is there a way to connect 2 RPi's to make a functional computer?

None of my Pis have attached keyboard, mouse or monitor. Two do not have microSD cards. All are functional, functioning computers, despite your assertion to the contrary. You're obviously a very clever pedant. Techies and SF fans.... I would hold that a Pi is a functional computer with only some fo...
by W. H. Heydt
Thu Jul 12, 2018 4:25 pm
Forum: Beginners
Topic: updates and upgrades
Replies: 2
Views: 145

Re: updates and upgrades

I do update/upgrade(usually dist-upgrade) as and when I feel like it. I should do it more often, but there are two things standing in the way of doing it very often. The first is that I would have to refresh at least 10 Pis, and that takes a while. The second is that some of them have various tweaks...
by W. H. Heydt
Thu Jul 12, 2018 4:10 pm
Forum: General discussion
Topic: Not just for kids
Replies: 3
Views: 2014

Re: Not just for kids

That's sweet. Thanks for sharing.
by W. H. Heydt
Thu Jul 12, 2018 6:03 am
Forum: Official Foundation Display
Topic: Display backlight current
Replies: 1
Views: 239

Re: Display backlight current

I believe the total current draw for the device at full backlight is about 250mA.
by W. H. Heydt
Thu Jul 12, 2018 6:02 am
Forum: Official Foundation Display
Topic: Bag for display and accessories?
Replies: 1
Views: 103

Re: Bag for display and accessories?

For my "travel alarm" (RPF 7" touchscreen, Pi2Bv1.1, a couple of USB bits, and a case), I got my wife to make a bag. We used one of the pieces of packing foam to protect the screen. The bag has a soft lining to prevent scratches. The speakers fit in a 1 gallon ziplock and the keyboard (built in trac...
by W. H. Heydt
Thu Jul 12, 2018 3:02 am
Forum: Beginners
Topic: Pip or Pip3 on RasPi Zero W is painfully slow
Replies: 2
Views: 104

Re: Pip or Pip3 on RasPi Zero W is painfully slow

There could be any of a number of causes, some fixable, some not. Here are a few that occur to me are: 1. The Pi0/Pi0W are among the slowest versions of the Pi. Check the settings to verify that it is running at 1GHz, as I've seen out-of-box installs run at 700MHz (the original default speed for the...
by W. H. Heydt
Thu Jul 12, 2018 12:01 am
Forum: General discussion
Topic: Is there a way to connect 2 RPi's to make a functional computer?
Replies: 15
Views: 660

Re: Is there a way to connect 2 RPi's to make a functional computer?

Now that you've been given the answer, let me expand it a bit. The first thing is: What do you mean by "a real computer"? Not only is a Pi (any model) a "real computer" (in the sense of "a general purpose digital electronic computer"), but it's a lot faster--and therefore, I suppose, more "real"--th...

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