Post by thread:FPGA/CPLD, Oscilloscope, Books, and serial port

All dollars are US$ FPGA: Cypress Semiconductor makes inexpensive entry level VHDL compiler. It comes with a book, although the book is only fair. You can order directly from Cypress for about $100, or you can buy one from a bookstore for about $60. It support fairly large number of Cypress devices, including (C)PLD and FPGA. I'm not sure about simple PLD support, but CPLD are usually better in most applications anyways. Books: For all your technical book needs, checkout OpAmp bookstore. They now have decent search engine, and they stock most books in store. If you are in LA or Orange County area in California, you can visit them in West Hollywood. http://www.opampbooks.com Oscilloscope: Radio Shack sells el cheapo digital scoope. It's about $100. It has a small LCD display and it also hooks up to a PC via RS232. Fastest sampling rate is 5 ns, but it doesn't have filters before the digitizing process. This means you'll see many foldovers if you sample high frequency stuff. It's good for quick and dirty stuff. In fact, I think it's a cheapest 5 MHz oscilloscope one can buy (digital or analog). Serial port: Does anyone know where I can get a serial port routine that works on interrupt basis? I want the PIC to perform computation while the data is being received (sort of multitasking). I have a sample serial code from Microchip, but it's not "multitasking". Please send me the source; I already know I should use port B state change interrupt, but I'm not sure how I would implement this. Thanks. Single Transistor RS 232 Receive +5 | \ /10k \ / |-----------TTL Sig out | / 10k |/ RS232 IN---/\/\/---|\ NPN (2N2222 or 2N3904) | \| | | GND Now the question is, is there such a solution for other direction (TTL in, RS232 out)? I looked at prices for MAXIM single supply transceiver devices and they are EXPENSIVE!

> Oscilloscope: > Radio Shack sells el cheapo digital scoope. It's about $100. It has a > small LCD display and it also hooks up to a PC via RS232. Fastest sampling > rate is 5 ns, but it doesn't have filters before the digitizing process. > This means you'll see many foldovers if you sample high frequency stuff. > It's good for quick and dirty stuff. In fact, I think it's a cheapest 5 MHz > oscilloscope one can buy (digital or analog). What's the grounding situation if the thing is plugged into a PC? Does it have any opto-isolation? If not, does its output have enough "oomph" do drive an opto?

On Fri, 6 Jun 1997 09:30:11 -0700, you wrote: > > Now the question is, is there such a solution for other direction (TTL >in, RS232 out)? I looked at prices for MAXIM single supply transceiver >devices and they are EXPENSIVE! > I found this years ago and it works great, tested on several machines and long cable length (>>30m ). + 5V +5V | \ \ / 2K2 E\ | \ BC557 \| | /|----+--/\/\/\/\--- TTL In C | 10K DB9 (2) ----------------+ | \ / 2K2 \ + 5V / | +-----+ \ | | / 10k | ----- \ \--/ ----- 10n / 1N4148 \/ | |-----------TTL Out ----- _|_GND | /C | 10k |/ DB9 (3) ----------+---------/\/\/---|\ BC547 | \E | _|_ GND Best regards, Gena

At 02:28 PM 6/6/97 -0500, you wrote: >> Oscilloscope: >> Radio Shack sells el cheapo digital scoope. It's about $100. It has a >> small LCD display and it also hooks up to a PC via RS232. Fastest sampling >> rate is 5 ns, but it doesn't have filters before the digitizing process. >> This means you'll see many foldovers if you sample high frequency stuff. >> It's good for quick and dirty stuff. In fact, I think it's a cheapest 5 MHz >> oscilloscope one can buy (digital or analog). > >What's the grounding situation if the thing is plugged into a PC? Does >it have any opto-isolation? If not, does its output have enough "oomph" >do drive an opto? > I bought one of these oscilloscopes. It is a nice idea, but the way it is implemented is little more than a toy, in my opinion. It has a 10MHz sampling rate (useful), but has 3 ranges, 1, 10, and 100 volts. It has about 4 (preset) trigger levels. The graphics looks good on the computer, though. You could build a little box to improve the input attenuator, and the trigger level, but I didn't. I bought a Tektronix TDS 220 instead. That is a real nice little oscilloscope!

> From: Andrew Russell Morris <spam_OUTamorrisTakeThisOuTMINDSPRING.COM> > To: .....PICLISTKILLspam@spam@MITVMA.MIT.EDU > Subject: Re: FPGA/CPLD, Oscilloscope, Books, and serial port > Date: Saturday, 7 June 1997 10:53 <snip> >. You could build a little box to improve the input attenuator, and > the trigger level, but I didn't. I bought a Tektronix TDS 220 instead. That > is a real nice little oscilloscope! Did you compare with the Fluke / Phillips in the same price range? I'd be interested in your comments, as I'm looking at this bracket of digitals. MikeS <mikesmith_ozKILLspamrelaymail.net>

At 12:54 PM 6/7/97 +0930, you wrote: >> From: Andrew Russell Morris <.....amorrisKILLspam.....MINDSPRING.COM> >> To: EraseMEPICLISTspam_OUTTakeThisOuTMITVMA.MIT.EDU >> Subject: Re: FPGA/CPLD, Oscilloscope, Books, and serial port >> Date: Saturday, 7 June 1997 10:53 > ><snip> > >>. You could build a little box to improve the input attenuator, and >> the trigger level, but I didn't. I bought a Tektronix TDS 220 instead. >That >> is a real nice little oscilloscope! > >Did you compare with the Fluke / Phillips in the same price range? I'd be >interested in your comments, as I'm looking at this bracket of digitals. > >MikeS ><mikesmith_ozspam_OUTrelaymail.net> > I looked at the Fluke Scopemeter and I liked the user interface of the TEK better. I use TEK digital scopes at work and I'm confortable with them. Digital knobs are faster to operate than buttons and I think the buttons would wear out faster. The Fluke had similar performance for the price. I don't need battery operation, but the portability is very nice. The TEK is not battery operated but they have one for several hundred dollars more. The form factor of the TEK is better suited to bench use and the form factor of the Fluke is better suited to handheld use. A coworker of mine uses and does not like the Fluke Scopmeter. Newer ones may be better, but he says that is not very user friendly. The TEK is very easy to use, especially if you're used to the other Tek scopes. At $995, I think the 60MHz TDS 210 is the best deal on the market. The 100MHz TDS 220 (mine) lists for $1695. I paid the extra money, because I needed a digital scope for my consulting work and the dealer was out of the TDS 210. TV repairmen are snapping them up as fast as they can get them in. I'm sure the extra bandwith will come in handy sometime. That is literally the only difference between the TDS 210 and the TDS 220.

> Single Transistor RS 232 Receive [figure deleted] > is there such a solution for other direction (TTL in, RS232 out)? It's fairly easy to build with 2 or more transistors. But you need a dual power supply. The output at the transmitter end should be +/-5 to +/-15 volts (EIA/TIA-232-E, 7-10-91, page 5). And the transmitter circuit must be capable of withstanding a short circuit. See the standard for more details. However, with a dual power supply on board, use the Motorola MC1488 & MC1489, TI 75188 & 75189, or equivalent RS232 driver circuits. There are newer versions available that use much less current. And these chips are inexpensive. > I looked at prices for MAXIM single supply transceiver devices > and they are EXPENSIVE! Well, charge pumping a +10V and a -10V supply from a +5V supply isn't free. Lee Jones ------------------------------------------------------------------- Jones Computer Communications @spam@leeKILLspamfrumble.claremont.edu 509 Black Hills Dr, Claremont, CA 91711 voice: 909-621-9008 -------------------------------------------------------------------

On Fri, 6 Jun 1997 09:30:11 -0700, you wrote: > Now the question is, is there such a solution for other direction (TTL >in, RS232 out)? I looked at prices for MAXIM single supply transceiver >devices and they are EXPENSIVE! > I found this years ago and it works great, tested on several machines and long cable length (>>30m ). + 5V +5V | \ \ / 2K2 E\ | \ BC557 \| | /|----+--/\/\/\/\--- TTL In C | 10K DB9 (2) ----------------+ | \ / 2K2 \ + 5V / | +-----+ \ | | / 10k | ----- \ \--/ ----- 10n / 1N4148 \/ | |-----------TTL Out ----- _|_GND | /C | 10k |/ DB9 (3) ----------+---------/\/\/---|\ BC547 | \E | _|_ GND Best Regards Gena

At 12:54 PM 6/7/97 -0500, you wrote: >At 12:01 PM 6/7/97 -0400, you wrote: ><snip>At $995, I think the >>60MHz TDS 210 is the best deal on the market. > >What is the fastest signal you can sample or sweep accurately (<5% >distortion)? >Can you read a 60MHz sine wave in differential mode and get perfect >calibrated amplitude? Have you measured that, or is it in the specs? > >JG > >Still using a Tek 453 (with a little interpretation) in Austin TX > Both the TEK TDS 210 and the TDS 220 have 1 Gigasample/S sample rates, per channel. I don't know about the newer ones, but the earlier Fluke Scopemeters split the sample rate up between both channels. The sample rate was half its single channel rate if both channels were in use. The TEK TDS 200 series scopes display and store 2500 points with 8 bit resolution. It can store two reference waveforms. With an optional $275 (what I paid for it) module it has GPIB, RS232 and Centronics interfaces. Hardcopy looks just like the screen. TEK sells software (I think it was about $300) to interface it to your PC. I haven't tried it yet. I have not tried to measure calibration accuracy in differential mode. It does have the ability to invert either channel or mathematically subtract them. To answer your question, I took a 15KHz, 5VP-P sinewave (all I had handy), activated the differential feature, and got about 0.1VP-P, using the X10 probes that came with the scope. The scope has coarse and fine calibration (user) adjustments. The cursors are automatically corrected to reflect whatever oddball scale factor the user has set up. The scope has an easy to read black on white backlit LCD display. I use the scope in my consulting work. I've had it about 6 month, but I have not had any problems with it. I would like it to scroll like a chart recorder when displaying very low frequencies, like the more expensive ones at work. It just sweeps normally at 5S/div max sweep time.

>just like the screen. TEK sells software (I think it was about $300) to >interface it to your PC. I haven't tried it yet. I have not tried to I have WaveStar software from TEK, which I got from Jensen. Jensen actually sells it for less than TEK sold it to them for! (At least, back a few months ago when I bought it). I LOVE IT! (BTW, I use it with a THS720) Anybody know the differences between the THS720 and the 720A? Thanks. Andy ================================================================== Andy Kunz - Montana Design - 409 S 6th St - Phillipsburg, NJ 08865 Hardware & Software for Industry & R/C Hobbies "Go fast, turn right, and keep the wet side down!" ==================================================================

{Quote hidden}>At 02:28 PM 6/6/97 -0500, you wrote: >>> Oscilloscope: >>> Radio Shack sells el cheapo digital scoope. It's about $100. It has a >>> small LCD display and it also hooks up to a PC via RS232. Fastest sampling >>> rate is 5 ns, but it doesn't have filters before the digitizing process. >>> This means you'll see many foldovers if you sample high frequency stuff. >>> It's good for quick and dirty stuff. In fact, I think it's a cheapest 5 MHz >>> oscilloscope one can buy (digital or analog). >> >>What's the grounding situation if the thing is plugged into a PC? Does >>it have any opto-isolation? If not, does its output have enough "oomph" >>do drive an opto? >> > >I bought one of these oscilloscopes. It is a nice idea, but the way it is >implemented is little more than a toy, in my opinion. It has a 10MHz >sampling rate (useful), but has 3 ranges, 1, 10, and 100 volts. It has >about 4 (preset) trigger levels. The graphics looks good on the computer, >though. You could build a little box to improve the input attenuator, and >the trigger level, but I didn't. I bought a Tektronix TDS 220 instead. That >is a real nice little oscilloscope! > Andrew; You say you got a Tektronix TDS 220 Scope I was looking at it but the price sounded to good to be true. I think it was around $995.00. Hows the LCD display? From the spec. sheet sounds like a real neet gadget... I'm tired fo lugging around my Tek 2246. David Jeffers OSP Technologies, Inc.

At 10:05 AM 6/10/97 -0700, you wrote: >>At 02:28 PM 6/6/97 -0500, you wrote: >>>> Oscilloscope: >>>> Radio Shack sells el cheapo digital scoope. It's about $100. It has a >>>> small LCD display and it also hooks up to a PC via RS232. Fastest sampling >>>> rate is 5 ns, but it doesn't have filters before the digitizing process. >>>> This means you'll see many foldovers if you sample high frequency stuff. >>>> It's good for quick and dirty stuff. In fact, I think it's a cheapest 5 MHz {Quote hidden}>>>> oscilloscope one can buy (digital or analog). >>> >>>What's the grounding situation if the thing is plugged into a PC? Does >>>it have any opto-isolation? If not, does its output have enough "oomph" >>>do drive an opto? >>> >> >>I bought one of these oscilloscopes. It is a nice idea, but the way it is >>implemented is little more than a toy, in my opinion. It has a 10MHz >>sampling rate (useful), but has 3 ranges, 1, 10, and 100 volts. It has >>about 4 (preset) trigger levels. The graphics looks good on the computer, >>though. You could build a little box to improve the input attenuator, and >>the trigger level, but I didn't. I bought a Tektronix TDS 220 instead. That >>is a real nice little oscilloscope! >> >Andrew; > >You say you got a Tektronix TDS 220 Scope I was looking at it but the price >sounded >to good to be true. I think it was around $995.00. Hows the LCD display? >From the >spec. sheet sounds like a real neet gadget... I'm tired fo lugging around my >Tek 2246. > >David Jeffers >OSP Technologies, Inc. > David; Check out the Tektronix web site at http://www.tek.com or http://www.tektronix.com. Complete specs. $995 is the list price for the 60MHz TDS210. The TDS220 is identical to it but 100MHZ. List price is $1695. I read in the Dutch magazine Elektuur (Dutch language version of Elektor) that TEK is raising the price on those scopes substantially the first of July. I'm sure that means the same thing in this country (USA). Better get yours before the price goes up.