With Android phone you can do:
- search for a photo after someone's face
which is a pretty complicated



Projects with Raspberry Pi:
http://www.itpro.co.uk/mobile/21862/raspberry-pi-top-22-projects-to-try-yourself/page/0/1
Live Calendar
PiTelephone - Retro rotary dial phone
<Raspberry Pi is the heart of hundreds of useful projects,>

Using the RetroPie emulation software, he was able to make a retro games console.
(There is DOSBox for Android)

Tell the Raspberry Pi for how long and at what temperature you want your tea brewed, and the Pi will activate the connected kettle, measure the temperature, and lower the tea in with a servo motor.

Raspberry Tor Router
Pi Multi-Room Music Player
Get Whatsapp on your Raspberry Pi
Power Cat Feeder

 

Raspberry Pi2 quad processor
Signal generator and Xoscope using SPI ADC and DAC for waveform generation and capture.

 

 

View attachment 120335

I've been looking for that DATASHEET for a long time.

 

What components have purchased and proved useful / useless?

---Emphasis added---

Inasmuch as 'products' (e.g. the "Pi") would seem to be the intended term:

It's a toss - but my 'entry' is (drum-roll please):

The Avcom TRSA-2500B -- In all fairness it wasn't a matter of false claims but, rather, missing features/ incompatible 'options' (as for instance unavailability of a decent tracking generator!) and much too much 'dumbed-down' automation at the expense of versatility! -- Hey - no need to laugh! -- I know! At ≈ $15k it was a painless enough lesson in the ways of 'ya get whatcha pay for' -- even so - there is a definite principle involved!

Best regards
HP

 

We should all remember the DEAD (Darkness Emitting Arsenide Diode).

 

We should all remember the DEAD (Darkness Emitting Arsenide Diode).

LOL! Initially, the video had me fairly shouting "it can't work 'against' non-coherent light!" --- Then came the segment featuring detail of the 'active region'

Very good! - You had me 'going' for a moment -- albeit 49 days early

Best regards
HP

 

Alright then -- Inasmuch as actual components seem to be 'fair game' after all -- My choice is the 6502 CPU - A fail in every respect by comparison to the Z80 (up to and including necessarily memory mapped IO space, a tediously small instruction set {sans the advantages of 'RISC'} and IMO, most appallingly, implementation of registers via on-chip dynamic ram) ---- Said devices being, for the benefit of 'millennials' and 'centennials', 8-Bit CPUs

Best regards
HP

 

Alright then -- Inasmuch as actual components seem to be 'fair game' after all -- My choice is the 6502 CPU - A fail in every respect by comparison to the Z80 (up to and including necessarily memory mapped IO space, a tediously small instruction set {sans the advantages of 'RISC'} and IMO, most appallingly, implementation of registers via on-chip dynamic ram) ---- Said devices being, for the benefit of 'millennials' and 'centennials', 8-Bit CPUs

Best regards
HP

"A fail in every respect by comparison to the Z80 ".

Price of 6502 (single quantities) in Sept. 1975 US$25 https://upload.wikimedia.org/wikipedia/commons/1/14/MOS_6501_6502_Ad_Sept_1975.jpg

Price estimate (no production quantities yet available) of Z80, Aug 1976 Byte article - US$200 (single quantities) US$80 (25-99) http://tech-insider.org/microprocessors/research/acrobat/7608.pdf

Personally, I liked the Z80 much better, but it's like saying that the Honda Accord fails in every way compared to the Bentley Continental or, in quantities of 25-99 a Maserati Quattroporte http://www.autoguide.com/new-cars/luxury-cars/

 

"A fail in every respect by comparison to the Z80 ".

Price of 6502 (single quantities) in Sept. 1975 US$25 https://upload.wikimedia.org/wikipedia/commons/1/14/MOS_6501_6502_Ad_Sept_1975.jpg

Price estimate (no production quantities yet available) of Z80, Aug 1976 Byte article - US$200 (single quantities) US$80 (25-99) http://tech-insider.org/microprocessors/research/acrobat/7608.pdf

Personally, I liked the Z80 much better, but it's like saying that the Honda Accord fails in every way compared to the Bentley Continental or, in quantities of 25-99 a Maserati Quattroporte http://www.autoguide.com/new-cars/luxury-cars/

Sincere thanks for that! --You've solved the mystery of the 6502's existence - and, indeed, use in many early microcomputer products (e.g. Ohio Scientific, Apple II, Commodore, etc...) -- Even so, the additional $175 ($800 adjusted for inflation) piece price would seem little enough to pay for conscientious, forward looking design...

Inasmuch as '75 was the year of my nativity - the 'zeitgeist' somehow escaped me - Even so, I don't want to believe electronics enthusiasts and 'tech consumers' of the day were that tightfisted?

Best regards
HP

 

Inasmuch as '75 was the year of my nativity - the 'zeitgeist' somehow escaped me - Even so, I don't want to believe electronics enthusiasts and 'tech consumers' of the day were that tightfisted?

Ah, 1975: the year my electronic geekiness reached full flower. That year I started work on my homebrew Motorola 6800 based machine. The processor was an XC6800, a pre-release version of the MC6800 that cost me $250 in 1975 money-- no tightfistedness there! Eventually it included 4KB of RAM made of Intel 2102 1Kx1 static RAM chips, 8K of EPROM (Intel 2716's), a homebrew video card that gave me 16 lines X 64 characters, a floppy-disc interface based on a Motorola 6852 SSDA (Synchronous Serial Data Adapter), an EPROM programmer and a parallel port to interface to a surplus keyboard salvaged from God-knows-what.

I still have my copy of Volume 1, Issue #1 of Byte magazine from September of 1975.

 

You may not have heard of the story of the 1975 Wescon conference and Steve Wozniak being given a handful of 6502's. At least that'sthe story I've heard. Even if that's not completely true it is true that Apple went that direction as we all know.

 

Ah, 1975: the year my electronic geekiness reached full flower. That year I started work on my homebrew Motorola 6800 based machine. The processor was an XC6800, a pre-release version of the MC6800 that cost me $250 in 1975 money-- no tightfistedness there! Eventually it included 4KB of RAM made of Intel 2102 1Kx1 static RAM chips, 8K of EPROM (Intel 2716's), a homebrew video card that gave me 16 lines X 64 characters, a floppy-disc interface based on a Motorola 6852 SSDA (Synchronous Serial Data Adapter), an EPROM programmer and a parallel port to interface to a surplus keyboard salvaged from God-knows-what.

I still have my copy of Volume 1, Issue #1 of Byte magazine from September of 1975.

https://archive.org/details/byte-magazine-1975-09

 

From that issue: how to recycle ICs:




Ha! A blow torch and vice grips. Boy have times changed.

 

From that issue: how to recycle ICs:

Ha! A blow torch and vice grips. Boy have times changed.

Not really, you should see some of the ham-fisted electronic repairs I've seen over the years.

 

From that issue: how to recycle ICs:

View attachment 120372

View attachment 120373
Ha! A blow torch and vice grips. Boy have times changed.

Embarrassing tho it is to confess - Many's the time I salvaged MC10EP.../MC100EP... (AKA 'ECLinPS' series) logic via precisely that method --- Definitely an 'open air' or fume hood procedure!

Nostalgically
HP

 

I have a Raspberry Pi and was not helpful. It is still very popular.
I did not understand why.

At the same price as Raspberry Pi you can buy a tablet. It has in addition touch display, WiFi, battery.
And a better processor.

Similar thoughts here as well.
I don't know how many times I have been told that if I got into those It could do XYZ such and such control work with them, provided I got all the additional adapter and whatever else composites to do it as well, which for the total cost came in at well over what I can buy a commercial grade general purpose PLC or PLR plug and play units for that come stock with all that I/O related stuff already built in, and ruggedized at that, plus I actually know how the program the damn things to boot.

 

Similar thoughts here as well.
I don't know how many times I have been told that if I got into those It could do XYZ such and such control work with them, provided I got all the additional adapter and whatever else composites to do it as well, which for the total cost came in at well over what I can buy a commercial grade general purpose PLC or PLR plug and play units for that come stock with all that I/O related stuff already built in, and ruggedized at that, plus I actually know how the program the damn things to boot.

Indeed! FWIW I regard Arduino, Raspberry Pi, and the (mercifully) 'late' Basic stamp as the 'trifecta of evil' where education (at least) is at issue -- That said, I suspect industry's rush to 'blur the line' delineating physical level engineering and mere software development is no more nefarious than greed (but then profit is their mission) --- Education's embrace of said path, on the other hand, is beyond reprehensible!

Hypertensively
HP

 

Indeed! FWIW I regard Arduino, Raspberry Pi, and the (mercifully) 'late' Basic stamp as the 'trifecta of evil' where education (at least) is at issue -- That said, I suspect industry's rush to 'blur the line' delineating physical level engineering and mere software development is no more nefarious than greed (but then profit is their mission) --- Education's embrace of said path, on the other hand, is beyond reprehensible!

Hypertensively
HP

The engineers that grew up on vacuum tubes and transitioned to transistors looked at uA741 op Amps and said, those are useless now and, no matter how much they improve, they always will be.

 

Indeed! FWIW I regard Arduino, Raspberry Pi, and the (mercifully) 'late' Basic stamp as the 'trifecta of evil' where education (at least) is at issue -- That said, I suspect industry's rush to 'blur the line' delineating physical level engineering and mere software development is no more nefarious than greed (but then profit is their mission) --- Education's embrace of said path, on the other hand, is beyond reprehensible!

Hypertensively
HP

It's just that too many people believe the hype that anyone can program, understand hardware and be able to easily create complex systems using knowledge gained by watching a few videos or taking a web-based class. Every person of expertise in any endeavor knows is mainly perspiration that gets you there and there is no spoon or shortcuts.