Question about RS232

Started by Bullwinkle in sci.electronics.design7 years ago 59 replies

Hi, i'm looking for an RS232 transceiver with these features 1. True Rs232 2. 3.3V as Vcc 3. 1Tx/1Rx 4. ESD protection 5. Lowest additional...

Hi, i'm looking for an RS232 transceiver with these features 1. True Rs232 2. 3.3V as Vcc 3. 1Tx/1Rx 4. ESD protection 5. Lowest additional components Any suggestion? I've found ADM3202: this doesn't meets all requirements (so i'm looking for something better), but reading datasheet i have a question: is true rs232 or not? If maximum voltage (with charge pump) is +-6.6V, how it can acce...


any suggestion to improve RS232 Signal Quality?

Started by Myauk in sci.electronics.design8 years ago 6 replies

Dear All, Could anybody suggest me what are the possible ways to improve the signal quality of 5 ft long RS232 Serial line at Baud Rate...

Dear All, Could anybody suggest me what are the possible ways to improve the signal quality of 5 ft long RS232 Serial line at Baud Rate 115200? I posted a question asking on flash programming failures via RS232 Serial Link, a few days ago. Here are more details on the issue. The connection link starts from Embedded PC to RS232 to 3V logic level converter, and then from the outputs o...


Cheapest way to add USB and 5 V and 3.3V power to a RS232 PIC project

Started by Jan Panteltje in sci.electronics.design3 years ago

Cheapest way to add USB and 5 V and 3.3V power to a RS232 PIC project Got some ebay USB To RS232 TTL PL2303HX Auto Converter Module...

Cheapest way to add USB and 5 V and 3.3V power to a RS232 PIC project Got some ebay USB To RS232 TTL PL2303HX Auto Converter Module Converter Adapter for arduino ebay object: 360750555245 Module has 5V and 3.3 V out (from the USB power). The PL2303 works 100% OK with Linux native drivers. Just connect to RS232 in and RS232 out, and power, and no need to write USB code, or get a sp...


Cheapest way to add USB and 5 V and 3.3V power to a RS232 PIC project

Started by Jan Panteltje in sci.electronics.design3 years ago 8 replies

Cheapest way to add USB and 5 V and 3.3V power to a RS232 PIC project Got some ebay USB To RS232 TTL PL2303HX Auto Converter Module...

Cheapest way to add USB and 5 V and 3.3V power to a RS232 PIC project Got some ebay USB To RS232 TTL PL2303HX Auto Converter Module Converter Adapter for arduino ebay object: 360750555245 Module has 5V and 3.3 V out (from the USB power). The PL2303 works 100% OK with Linux native drivers. Just connect to RS232 in and RS232 out, and power, and no need to write USB code, or get a sp...


[OT?]When an USB to RS232 converter is not "transparent"? DTR DSR loopback?

Started by blisca in sci.electronics.design10 years ago 1 reply

I have to solve this ..by phone!,i need your help,or your hints. There is a little application done in VB that reads and sends data to...

I have to solve this ..by phone!,i need your help,or your hints. There is a little application done in VB that reads and sends data to a board using the MSComm object.It works fine on a Pc with its RS232 serial port. As noticed newest laptops has plenty of USB's but no RS232 ports. So a USB to serial was bought,installed as a COM1 (or COM3 i don't remeber exactly now) with no conflicts a...


Breaking the price barrier: An autoranging frequency counter with RS232 output

Started by Jan Panteltje in sci.electronics.design8 years ago 8 replies

I found a nice auto ranging frequency counter online here: http://freenet-homepage.de/dl4yhf/freq_counter/freq_counter.html Did not have...

I found a nice auto ranging frequency counter online here: http://freenet-homepage.de/dl4yhf/freq_counter/freq_counter.html Did not have those 7 segment displays, considered an LCD interface, but why not use RS232, and power it from the RS232 too? Just a probe you can bring along with your laptop, saves weight :-) So.. modified that code a bit:-) This is what the output looks like: ftp...


rs232 interupt on old ibm pc type machines

Started by Hul Tytus in sci.electronics.design4 years ago 3 replies

sci.electronics.design rs232 interupt on old ibm pc type machines Below are an rs232 initialization and a handler routine that work well on...

sci.electronics.design rs232 interupt on old ibm pc type machines Below are an rs232 initialization and a handler routine that work well on later vintage ibm pc types, roughly 200 mc and above. The AT vintage types however are a bust. The 8250 registers and the interupt mask register in the interupt controller appear as expected in both cases. Anyone have an idea what is missing f...


Windows RS232 monitor

Started by mkr5000 in sci.electronics.design9 years ago 14 replies

Does anyone know of a simple program to look at a PC's RS232 port? There are so many on Download.com, I don't know where to start. I need one...

Does anyone know of a simple program to look at a PC's RS232 port? There are so many on Download.com, I don't know where to start. I need one that will display each byte in it's binary form on the screen. (Many are ascii). Doesn't need to communicate, just display the received data. Thanks.


modern RS232 ports

Started by John Larkin in sci.electronics.design6 years ago 85 replies

I know that many modern "RS232" ports are actually not RS-232 spec compliant. I can test a few gadgets we have around here, but I...

I know that many modern "RS232" ports are actually not RS-232 spec compliant. I can test a few gadgets we have around here, but I was wondering if anybody else has seen wildly non-compliant ports. Does everybody still even bother to swing negative on drivers? What are the smallest drive excursions anyone's seen? I know that my HP computer receivers will blow up if they see honest +-1...


Steps to program P89V51RD2 by ISP method using RS232

Started by Srinivas Nayak in sci.electronics.design5 years ago

After long discussions and try, I was able to successfully able to program = P89V51RD2 by In Situ Programming (ISP) method using RS232. In a hope...

After long discussions and try, I was able to successfully able to program = P89V51RD2 by In Situ Programming (ISP) method using RS232. In a hope that i= t shall be useful to other members, I would like to post my experience with= simple steps. For my success, I shall thank all our friends, who have help= ed me clearing my doubts and have provided their help and suggestions.=20 Here are th...


Looking for simple way to interface BCD to serial (RS232)

Started by RFI-EMI-GUY in sci.electronics.design8 years ago 51 replies

I have a device that has a three digit LED display. The chip that drives the LED also has four Binary Weighted outputs (1,2,4,8) and three...

I have a device that has a three digit LED display. The chip that drives the LED also has four Binary Weighted outputs (1,2,4,8) and three address pins for 100's, 10's and units. I want to drive a FIFO UART of some sort to output an RS232 stream so that this device can update a software program. Baud rate 300 to 4800 range would be nice if possible. The updates are about 300/second I...


USB to Serial adaptor

Started by Oppie in sci.electronics.design4 years ago 41 replies

Does anybody have a favorite USB to RS-232 adaptor that they can recommend? Evidently some are not created equal and have had some issues. A...

Does anybody have a favorite USB to RS-232 adaptor that they can recommend? Evidently some are not created equal and have had some issues. A colleague in France reported that he had found some discrepancies in how the grounding was accomplished: "It appears that the RS232 plug body is NOT always bound to USB plug body, nor to the pin 5 (ground) of the rs232 plug, so that finally there...


A cheap very accurate LC meter with RS232 interface

Started by Jan Panteltje in sci.electronics.design7 years ago 26 replies

A cheap ( < 10 $) very accurate LC meter with RS232 interface. http://panteltje.com/panteltje/pic/lc_pic/ All credit goes to somebody else...

A cheap ( < 10 $) very accurate LC meter with RS232 interface. http://panteltje.com/panteltje/pic/lc_pic/ All credit goes to somebody else (actually a lot of people) for this design. I merely simplified it some more :-) It seems to be very accurate, and is most useful if you are winding your own inductors or working with RF and extremely small capacitors, a few pF is no problem for this.


A RS232 powered thermocouple adaptor + software (Linux).

Started by Jan Panteltje in sci.electronics.design7 years ago

A RS232 powered thermocouple adaptor + software (Linux). http://panteltje.com/panteltje/pic/th_pic/ This accepts 4 thermocouples of type E,...

A RS232 powered thermocouple adaptor + software (Linux). http://panteltje.com/panteltje/pic/th_pic/ This accepts 4 thermocouples of type E, J, K, R, S, or T. and displays the temperatures in Kelvin and Celsius. Purely experimental, and not tested a lot.


A cheap very accurate LC meter with RS232 interface

Started by Jan Panteltje in sci.electronics.design7 years ago 2 replies

Update A cheap ( < 10 $) very accurate LC meter with RS232 interface. http://panteltje.com/panteltje/pic/lc_pic/ Updated the website, added an...

Update A cheap ( < 10 $) very accurate LC meter with RS232 interface. http://panteltje.com/panteltje/pic/lc_pic/ Updated the website, added an explanation how it works, derived the equations for Cx and Lx, and updated the software.


Instrument with analog output, cheap and on RS232/USB

Started by Klaus Kragelund in sci.electronics.design5 years ago 12 replies

Hi For a test setup I often need an analog signal to feed into the device under test. So I need a instrument with an anlog output. It needs...

Hi For a test setup I often need an analog signal to feed into the device under test. So I need a instrument with an anlog output. It needs to run on RS232 or USB I could roll my own, with a eval board, but have no time to spend on that Anyone know of a cheap model (no the National Instruments, NIDaqs, they are prohibitive expensive) Thanks Klaus


RS232 autoranging frequency counter update

Started by Jan Panteltje in sci.electronics.design8 years ago 3 replies

RS232 autoranging frequency counter update. Added input cap, and build it into a D connector, photos here: ...

RS232 autoranging frequency counter update. Added input cap, and build it into a D connector, photos here: http://panteltje.com/panteltje/pic/freq_pic/ Bet his is the smallest frequency counter on earth :-)


Ground currents blowing up my CM choke

Started by Allan Herriman in sci.electronics.design6 years ago 58 replies

Hi, I recently designed a product with an RS232 port on it. I put a common mode choke on the ground and data lines to reduce EMI. Two...

Hi, I recently designed a product with an RS232 port on it. I put a common mode choke on the ground and data lines to reduce EMI. Two ground lines, Tx data and Rx data go through the choke. The choke I chose was a tiny eight terminal 0805 thing with an 80mA rating. At the time I thought that would be adequate for RS232, but we've managed to destroy a number of them through regul...


GPS frequency counter + PLL PIC based

Started by Jan Panteltje in sci.electronics.design5 years ago 1 reply

To 'stabilize' the frequency from the 'twisted' wire oscillator as described in previous posts, and to be able to set it via RS232 and read it, I...

To 'stabilize' the frequency from the 'twisted' wire oscillator as described in previous posts, and to be able to set it via RS232 and read it, I wrote some PIC 18F14K22 asm and added a simple 2 line LCD. The first line shows the requested frequency ,as typed in via RS232. The bottom line shows the measured frequency (against a 10 MHz xtal). http://panteltje.com/pub/GPG_freq_counter_PLL_IMG_...


SPI to RS232 Conversion

Started by Artist in sci.electronics.design8 years ago 25 replies

I want to use the MAX9939, http://datasheets.maxim-ic.com/en/ds/MAX9939.pdf, on a board with no uP and control it instead with an RS232 serial...

I want to use the MAX9939, http://datasheets.maxim-ic.com/en/ds/MAX9939.pdf, on a board with no uP and control it instead with an RS232 serial port from a PC. I thought at first I could do this with the MAX3110E: http://datasheets.maxim-ic.com/en/ds/MAX3110E-MAX3111E.pdf but after reading this spec sheet I notice that on both the MAX3110E and the MAX9939 the SCLK line is an input. Evidentl...