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by hippy
Wed Nov 22, 2017 6:49 pm
Forum: Compute Module
Topic: Op Amp / Power op amp help with CM3 audio
Replies: 14
Views: 197

Re: Op Amp / Power op amp help with CM3 audio

Any ideas on my bluetooth query Volume control for audio sent over bluetooth would be controlled entirely by software. If you want a physical pot to control volume you will need some sort of ADC to read in what the pot position is. You could use a dual-gang pot to control both the headphone/speaker...
by hippy
Wed Nov 22, 2017 6:39 pm
Forum: Off topic discussion
Topic: Question about some VERY old LED displays
Replies: 6
Views: 141

Re: Question about some VERY old LED displays

And don't forget to double-check the code to make sure you are not doing something silly like clearing all the other segment bits when the DP is set.

You could possibly swap the DP GPIO with some other segment GPIO to see if it exhibits similar behaviour.
by hippy
Wed Nov 22, 2017 2:38 pm
Forum: Beginners
Topic: raspberry pi 3 record decibels
Replies: 1
Views: 39

Re: raspberry pi 3 record decibels

It will probably be easiest and cheaper to buy or build a microphone preamplifier circuit which includes a peak detector and comparator. The Pi then just needs to monitor the digital input going high to know the sound detection level is exceeded and turn the lamp on. You might not even need the Pi.
by hippy
Wed Nov 22, 2017 2:32 pm
Forum: Compute Module
Topic: Op Amp / Power op amp help with CM3 audio
Replies: 14
Views: 197

Re: Op Amp / Power op amp help with CM3 audio

In your original specification it seemed you wanted stereo for the headphones, mono for the speakers when the headphones were not plugged-in.

Has that specification changed ?
by hippy
Wed Nov 22, 2017 12:32 pm
Forum: Compute Module
Topic: Op Amp / Power op amp help with CM3 audio
Replies: 14
Views: 197

Re: Op Amp / Power op amp help with CM3 audio

This is the earlier thread -

viewtopic.php?f=91&t=198080
by hippy
Tue Nov 21, 2017 7:39 pm
Forum: General discussion
Topic: FCC Certification for Pi in a Box
Replies: 24
Views: 2799

Re: FCC Certification for Pi in a Box

Seriously though, I am reminded of the statement that it is sometimes better to seek forgiveness than permission. It all comes down to how one measures "better". In the majority of cases I would say it's better to do something properly, in accordance with all the onerous rules, regulations and laws...
by hippy
Tue Nov 21, 2017 7:12 pm
Forum: Other
Topic: Chromium OS on RPi Zero
Replies: 4
Views: 101

Re: Chromium OS on RPi Zero

"19 Aug 2017: This is a quick tutoial on installing chromium OS on raspberry pi. This process can be done on Raspberry pi 3, raspberry pi 2, and raspberry pi zero"

https://www.youtube.com/watch?v=n2OegzQRa-4

Not sure how accurate that is but may be worth checking out.
by hippy
Tue Nov 21, 2017 6:55 pm
Forum: Automation, sensing and robotics
Topic: Changing battery running Pi
Replies: 7
Views: 226

Re: Changing battery running Pi

If your Pi, sensors and anything else connected can run on slightly less than 5V you could perhaps parallel-up two battery connections through diodes. Plug in the new, remove the old, repeat. You could have a DPST switch which bypasses the diodes once swapped so you would be back to 5V and have less...
by hippy
Tue Nov 21, 2017 6:37 pm
Forum: General discussion
Topic: How to use Raspberry as Hi fi sound card in desktop pc
Replies: 8
Views: 284

Re: How to use Raspberry as Hi fi sound card in desktop pc

mahjongg wrote:
Tue Nov 21, 2017 5:53 pm
You will also need specific software to emulate an USB sound device, I don't think that exists.
The Pi appears to have OTG g_audio support included.
by hippy
Tue Nov 21, 2017 1:28 pm
Forum: Other projects
Topic: Is there any sort of semi flexible breadboards?
Replies: 5
Views: 167

Re: Is there any sort of semi flexible breadboards?

It doesn't really seem that 'breadboard' would be the appropriate solution for this application. It would be easier to find or make a pipe or section of pipe with the correct diameter as you sugest, drill holes, push LED's through them, then wire by hand, or fix LED strips as suggested. Perhaps you ...
by hippy
Tue Nov 21, 2017 12:33 pm
Forum: Beginners
Topic: FCC certification for Pi Zero W with case
Replies: 13
Views: 566

Re: FCC certification for Pi Zero W with case

this rule says that I can place the Pi Zero W into my product provided that it is accessible by the end user and I put the ID on an easily-opened enclosure That would be my reading of it too; paraphrased, 'an FCC certified Pi placed in a case doesn't require additional FCC certification'. It would ...
by hippy
Tue Nov 21, 2017 12:07 pm
Forum: Beginners
Topic: What are amp op / differential amp op? - What would be best for my project?
Replies: 10
Views: 233

Re: What are amp op / differential amp op? - What would be best for my project?

Okay so let me get this straight everything before the the output of the op amp is fine. No, not if you are talking about the last circuit you posted. You would be better off asking on a forum more related to audio circuitry as members there will be better able to point to useful resources to expla...
by hippy
Tue Nov 21, 2017 9:50 am
Forum: Beginners
Topic: What are amp op / differential amp op? - What would be best for my project?
Replies: 10
Views: 233

Re: What are amp op / differential amp op? - What would be best for my project?

Also I've noticed online including hippy's own design an singular op amp and then I've noticed ones with 2-3 in them. What's the difference in the increased number of 3 op amps in the circuit? Does it provide less noise and clearer sound? Without seeing where the op-amps are placed or knowing how t...
by hippy
Mon Nov 20, 2017 4:55 pm
Forum: Advanced users
Topic: GPS Simulator/Emulator
Replies: 7
Views: 238

Re: GPS Simulator/Emulator

I dug around and couldn't find anything low priced, not even systems using off-the-shelf SDR's. It's a whole new ballpark to hijacking heart rate monitor watches and faking radio time code signals which only need a coil of wire and a $1 micro. I think we are safe from rogue CubeSats and miscreants o...
by hippy
Mon Nov 20, 2017 1:38 pm
Forum: Beginners
Topic: What are amp op / differential amp op? - What would be best for my project?
Replies: 10
Views: 233

Re: What are amp op / differential amp op? - What would be best for my project?

Amp op use only 1 input While differential amp op uses 2 inputs (like our left & right channels) Op-amps usually have a "+" and a "-" input which is I think what's being meant by "differential" here. One doesn't usually use "+" and "-" to combine stereo into a mono output as seems to be the goal. O...
by hippy
Mon Nov 20, 2017 1:22 pm
Forum: Advanced users
Topic: GPS Simulator/Emulator
Replies: 7
Views: 238

Re: GPS Simulator/Emulator

OP doesn't want the Pi to emulate a GPS dongle. OP wants the Pi to emulate a GPS satellite ... In fact needs to generate the signals to fake a small, four satellite, constellation looking at the OP. It is not my area of expertise and I would guess it's a pretty specialised field. I would expect it'...
by hippy
Mon Nov 20, 2017 12:36 pm
Forum: Graphics, sound and multimedia
Topic: Portable audio player for kids
Replies: 7
Views: 187

Re: Portable audio player for kids

So what's a recommended way to make a raspberry and some additional power using extension (like e.g. an amplifier) portable in terms of power supply - while not having power management issues? I don't think there is any recommended way as such. The Pi wasn't designed for the mobile use you are requ...
by hippy
Sun Nov 19, 2017 5:24 pm
Forum: Other
Topic: please provide a x86_64 version of your: "Debian with Raspberry Pi Desktop"
Replies: 2
Views: 139

Re: please provide a x86_64 version of your: "Debian with Raspberry Pi Desktop"

CyberManifest wrote:
Sun Nov 19, 2017 3:34 am
I'm having difficulties installing the atom text editor found at: https://atom.io/ because they no longer provide a 32 bit .deb package.
Did you contact the atom.io team to also ask that they provide a suitable 32-bit package ? If not I would suggest you do.
by hippy
Sun Nov 19, 2017 4:55 pm
Forum: Graphics, sound and multimedia
Topic: Portable audio player for kids
Replies: 7
Views: 187

Re: Portable audio player for kids

You could buy a cheap MP3 player module with in-built amplifier, add buttons, and have something far cheaper than what you propose and not have half the problems a Pi without power management would have. Eg - http://www.ebay.co.uk/itm/TF-card-U-disk-MP3-Format-decoder-board-module-amplifier-decoding...
by hippy
Sun Nov 19, 2017 4:04 pm
Forum: General discussion
Topic: Best way to control 179 things individually
Replies: 14
Views: 557

Re: Best way to control 179 things individually

It seems 23 sets of 8-bit shift registers or 12 sets of 16-bit I2C output latches would be the simplest way to go. You might be able to find a CPLD or FPGA with 179 outputs and build one huge 179-bit shift register or I2C output latch in a single chip. I think it now comes down to what your criteria...
by hippy
Sat Nov 18, 2017 7:32 pm
Forum: Beginners
Topic: SMB shares went wild
Replies: 9
Views: 261

Re: SMB shares went wild

This means that any unknown user that connects to samba will be allowed in, whether they can do anything once they are in depends on the permissions on the share. That seemed to be the issue I had with my PC's accessing my upgraded Pi because of the change of Samba defaults. Authorised users weren'...
by hippy
Sat Nov 18, 2017 7:07 pm
Forum: General discussion
Topic: Combining Voltage From Multiple GPIO Pins?
Replies: 10
Views: 426

Re: Combining Voltage From Multiple GPIO Pins?

Has anyone tried a voltage doubler on a logic output? I have done it like this with a 5V micro, which is included in Heater's provided link ... -.- +5V | `---|>|----.----|>|----.----> +10V (ish) __|__ + __|__ + C1 ==.== C2 ==.== | | OUT >-------' _|_ 0V When 'OUT' is low (0V), C1 charges towards 5V...
by hippy
Sat Nov 18, 2017 1:03 pm
Forum: General discussion
Topic: Secure delete/erase SD using encryption
Replies: 11
Views: 396

Re: Secure delete/erase SD using encryption

As ghans says; it is not possible to guarantee complete destruction of all data which has been written to an SD Card. The only way to guarantee that is to physically destroy the silicon in the card. It is not the data one can easily see which is the problem but that which one can't; those blocks whi...
by hippy
Sat Nov 18, 2017 12:37 pm
Forum: General discussion
Topic: Raspberry pi as "brains" for hardware
Replies: 6
Views: 257

Re: Raspberry pi as "brains" for hardware

You still need an operating system as the pi is a computer, not a microcontroller like the arduino A Pi can be used as if a microcontroller; using Ultibo or bare metal or by running code booted into the GPU and not even firing-up the ARM cores. That won't be using a Pi to its full potential, may be...
by hippy
Fri Nov 17, 2017 6:13 pm
Forum: General discussion
Topic: thoughts on prices and features for addons
Replies: 9
Views: 374

Re: thoughts on prices and features for addons

The main reason the Pi is relatively cheap is because it has the expertise of people working towards keeping it as cheap as possible, can enjoy economies of scale due to the huge numbers manufactured, and it doesn't need to turn much of a profit per board. Third-party add-on suppliers are often simp...

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