Is DSP useful?

[JC1]

50 ma make more sense

D-Tex used to be Bill Mahan's company in the 60's. It was resurrected in the 80's, maybe by his son, I don't know. But it disappeared after only a couple of years. Maybe he blew all his funds on a DSP designer!

I was googling dsp metal detector algorithms to see if I

could find something some university or whatever might

have done with public money, get some of it done for free.

Or some good ideas, of which there have been many over

the years. Some of the walkthroughs use DSP more for

real, but then they are plugged into the wall for power,

and not much space constraint. Still is a challenge.

Poor DTex. The DSP Monster probably ate em up.

Took a bit bite out of some others.

Should of used Wavelets, I told them they should of

used Wavelets.



An embedded computer using sophisticated software provides high speed Digital Signal Processing (DSP) and self-monitoring diagnostic programs which ensure consistent, highly stable drift free operation.


The ability to reject interference (electromagnetic noise) from outside sources, separates the quality detector from others. This type of interference, caused by equipment such as fluorescent light ballistics, computer monitors and photocopiers cause inferior units to regularly false alarm. Some manufacturers mask noise rejection problems by using IR sensors' that deactivate their units until a person walks through. These IR devices, sometimes referred to as traffic counters, can actually allow weapons or contraband to be passed, slid or tossed through the detector without it alarming! Avoid dangerous security breaches by selecting a detector that is continuously active

The 18 ZONE uses highly efficient electromagnetic interference rejection algorithms and unique circuitry to eradicate the high false alarm rates common to many detectors. The unit thrives in environments where other detectors are rendered inoperative.

http://www.feelsafer.com/18zone.html

[JC1]

GPR and DSP

Alphabet detectors.

This talks about GPR and DSP and finding pipes, metal and

non metal items. Deep, with some problems, of course.

Caution 4Mb Pdf kinda slow. Before you click.

http://www.osti.gov/bridge/servlets/...ive/841082.PDF

[Delbert grady]

best one

Pic 30 vs MPS430

[JC1]

This vs That

Hi Delbert,

cut and paste, saves me the trouble.


Microcontrollers

Anyone can argue PIC vs. MSP430 vs. AVR vs. etc. The PICs tend to come out cheaper than MSP430 or AVR, for similar features, and I find them easier to program in assembler. That's lucky, because the PICs are very close to hopeless to compile for. The PIC18s are somewhat better, but still just weird.

gcc ports exist for both MSP430 and AVR; I've used both, and never found a bug in either. The JTAG thing with the MSP430s always seemed a bit stupid to me, a quarter of the pins on the device, but now they have the Spy-by-Wire parts. It's nice that you can get five-volt-tolerant AVRs; that hasn't gone away yet.

I like the latest ARM parts. Digikey has the Sharp LH754XX, and I found those very nice to use. (These are not microcontrollers; you must wire them to flash and to RAM. They have all sorts of good peripherals on-chip, though, including many kinds of LCD controller, and the datasheets are extremely well-done.) I've used the Atmel AT91SAM7 ARM parts extensively, including their AT91SAM7X, with Ethernet; these put a lot of neat applications within reach. I have not been impressed with their datasheets or software support, though. ST has a comparable line of ARMs, which I have not investigated.

http://www.cq.cx/parts.pl

http://focus.ti.com/mcu/docs/mcuprod...ther+IL+msp430

http://www.nabble.com/Harvard-vs-von...-t1853153.html

[JC1]

My Pick

Take a look at Silicon Laboratories

C8051F064 thru 067 parts.

They have a 16 bit 1 Megasample/sec A/D.

Of course few 16 bit coverters are accurate to 16 bits.

But this is not bad, and can do conversions and get data

at 1 us intervals. i.e. digitize PI return pulse, then process

before next pulse.

get alot in one package for 20 bucks.

take a look, digikey sales them.

Silicon Labs data short

http://www.silabs.com/public/documen...F064_short.pdf

http://en.wikipedia.org/wiki/Silicon_Laboratories

I still pick the hardware first.

support second.

Assembly.

[JC1]

Had to Look

Delbert Grady is a fictional character and an antagonist in the 1977 novel The Shining by Stephen King and in the 1980 film of the same name directed by Stanley Kubrick. In the film, Delbert Grady was portrayed by British actor Philip Stone (1924-2003).

In the film, Jack Torrance (portrayed by Jack Nicholson) takes the job of winter caretaker at the fictional Overlook Hotel in Colorado. It is revealed to him that the previous caretaker, Charles Grady, had gone insane from cabin fever and murdered his wife and two young daugthers. When Torrance himself begins to hallucinate, Grady appears in a waiter's uniform, spills a drink on Torrance, apologizes profusely and takes Torrance to the restroom to wash the stain off.

The viewer is probably meant to infer that the hotel is haunted by numerous dangerous spirits, including that of Delbert Grady.

http://en.wikipedia.org/wiki/Delbert_Grady

Now thats funny.

[JC1]

Ah sooo...

doing my homework.

Sean Goddard of Pulsar Electronics

interesting.

http://www.norfolkwolf.co.uk/coinscanner2.php

Now where did he go

anyway????

[Carl-NC]

I've only worked with PICs, and I agree that programming them in C can be a little frustrating. ADI, AVR, TI and others have better peripherals (ADCs, DACs, etc) but I've stuck with PIC because of their overwhelming popularity amongst hobbyists (easy to find help).

On converters, ADI has just released an 18b/1MSps @ 8mW . Serial out, 10-pin pkg.

- Carl

[Unregistered]

K-Pax

Sean has gone back to K-Pax for a few days

[Delbert grady]

pic30

Just looked up Pic DSP 30 on Mplab and its there. But does not support the Pickstart plus. So how do people program these. Can't do compiler stuff has to be machine code for me.

[Unregistered]

If your looking at using the DSPIC then apply for the Design Contest but don't worry about your entry and get an ICD2 for $99.

http://www.circuitcellar.com/microchip2007/tools.html

I used to like Microchip but latley less and less seems to work with out one issue or another.

Carl - is that the AD7982? looks intresting

JC1 - I also like the AT91SAM7 range and I think a good stating point would be a Atmel SAM7-64 header board for $36 + a free GNU tool chain.

http://www.sparkfun.com/commerce/pro...roducts_id=614

[Carl-NC]

Carl - is that the AD7982? looks intresting

Yup. Price is high, but that'll change with competition.

[JC1]

Micros

Hey Guys,

Don't forget that if you are going to manufacture and sell

something for real, you may not want to use the latest and

greatest parts. Why? Because they may quit making them

and now you have to redesign, reprogram, whatever.

One of the big reasons the same old parts keep showing

up over and over like old and not even close to being

considered good by todays standards, 4016, 4053, etc.

analog switches. But there they are along with all the other

stuff you could get 20 + years ago. Still there is a very

good reason to keep using it, it is cheap, several make it,

you can still get it 10 years from now.

Like a Z80 processor.

ugh.

[Carl-NC]

There are drawbacks. Power, PCB footprint, and, obviously, performance. My 2mA PI design uses chips that are all fairly recent (2-3 yrs). I could not have come even close to 2mA using vintage chips. Or fit the whole thing in 3 square inches.

But, in Hammerhead, I intentionally took the vintage chip approach, precisely for widespread availability.

- Carl

[Unregistered]

There are drawbacks. Power, PCB footprint, and, obviously, performance. My 2mA PI design uses chips that are all fairly recent (2-3 yrs). I could not have come even close to 2mA using vintage chips. Or fit the whole thing in 3 square inches.


- Carl

Can I add that 20+ years ago you could not find a 40 MIPs embedded processor with 1MSPS 12bit ADC, 64K EEPROM and 4k RAM for $5. If you tried to design it today using 20+ parts it would cost a lot more than $5.

A design shelf life is rarely more than 2 years anyway now, yes you can always quote a classic design but they are rare these days. If I where to put on the market a detector that utilised DSP @ 1MSPS rate within six months my competitor would be claim in advertisements that true DSP requires a sampling rate of 2 MSPS to work properly. This means that I now have to change my design to a sampling rate of 3 MSPS anyway.

When you look at the development of a lot of designs, you will find a lot of the same 20 years old parts because as a designer you don’t change anything until it’s broken or the sales team tell you the need something new, in which case you change as little as possible. Another argument often quoted for basic parts is reparability, in the market place it makes no sense to spend $45 repairing a board that cost $25 to manufacture.

Don’t get me wrong is not all great, over the last 18 months I have been involved in designs that utilised Microchips ENC28J60 in those months they have never produce one that meets the datasheet specification.