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AnswerRe: atmega32 programmer Pin
rakesh422512-Sep-10 3:33
rakesh422512-Sep-10 3:33 
QuestionWhat is the effect of FILE_SYNCHRONOUS_IO_ALERT in ZwCreateFile? Pin
followait31-Aug-10 17:12
followait31-Aug-10 17:12 
AnswerRe: What is the effect of FILE_SYNCHRONOUS_IO_ALERT in ZwCreateFile? Pin
fat_boy8-Sep-10 1:20
fat_boy8-Sep-10 1:20 
AnswerRe: What is the effect of FILE_SYNCHRONOUS_IO_ALERT in ZwCreateFile? Pin
fat_boy8-Sep-10 1:24
fat_boy8-Sep-10 1:24 
Questionusb to rs232 Pin
ammeer_a30-Aug-10 9:43
ammeer_a30-Aug-10 9:43 
AnswerRe: usb to rs232 Pin
Luc Pattyn30-Aug-10 10:26
sitebuilderLuc Pattyn30-Aug-10 10:26 
GeneralRe: usb to rs232 Pin
ammeer_a30-Aug-10 10:36
ammeer_a30-Aug-10 10:36 
GeneralRe: usb to rs232 Pin
Roger Wright30-Aug-10 10:48
professionalRoger Wright30-Aug-10 10:48 
While the original RS232 spec called for voltages of around 12 to 18V, modern implementations are almost exclusively 5 volt designs. The USB standard provides for each port to deliver a small amount of 5 volt power to connected devices, which is what makes possible many popular USB devices, including your RS232 converter. The key word is "small" however, and USB does not provide enough power to deliver a serial connection very far.

Driving a cable requires the ability to source and sink a fair amount of current, primarily because the cable "looks like" a capacitor that must be charged and discharged for every change of state. Microprocessors like the AVR are built mainly using CMOS technology, which cannot source or sink much current, so external bipolar circuits are almost always required. Special circuits like the MAX232 require very little input current, and so can be driven by a micro directly, but they can move larger currents on the RS232 side. Depending on what form your AVR takes (bare processor, development board, custom circuitry) you may or may not need this extra buffering. Check the documentation for what you have to work with. If it specifies a serial port without mentioning RS232, you can be fairly sure that you need to provide this extra circuit for the connection to the outside world.
Will Rogers never met me.

GeneralRe: usb to rs232 Pin
Luc Pattyn30-Aug-10 11:01
sitebuilderLuc Pattyn30-Aug-10 11:01 
AnswerRe: usb to rs232 Pin
fat_boy31-Aug-10 0:50
fat_boy31-Aug-10 0:50 
GeneralRe: usb to rs232 Pin
Luc Pattyn31-Aug-10 2:38
sitebuilderLuc Pattyn31-Aug-10 2:38 
GeneralRe: usb to rs232 Pin
fat_boy31-Aug-10 2:49
fat_boy31-Aug-10 2:49 
GeneralRe: usb to rs232 Pin
Roger Wright31-Aug-10 3:23
professionalRoger Wright31-Aug-10 3:23 
GeneralRe: usb to rs232 Pin
Rick York31-Aug-10 20:52
mveRick York31-Aug-10 20:52 
Questioncheap and interesting hardware for practising Pin
followait29-Aug-10 18:23
followait29-Aug-10 18:23 
AnswerRe: cheap and interesting hardware for practising Pin
Richard MacCutchan29-Aug-10 21:13
mveRichard MacCutchan29-Aug-10 21:13 
AnswerRe: cheap and interesting hardware for practising Pin
jujiro10-Sep-10 5:57
jujiro10-Sep-10 5:57 
QuestionZwCreateFile parameter [modified] Pin
followait29-Aug-10 13:59
followait29-Aug-10 13:59 
QuestionATmega16 simulation Pin
ammeer_a29-Aug-10 12:07
ammeer_a29-Aug-10 12:07 
AnswerRe: ATmega16 simulation Pin
Luc Pattyn29-Aug-10 12:25
sitebuilderLuc Pattyn29-Aug-10 12:25 
GeneralRe: ATmega16 simulation Pin
ammeer_a29-Aug-10 12:31
ammeer_a29-Aug-10 12:31 
AnswerRe: ATmega16 simulation Pin
Luc Pattyn29-Aug-10 12:33
sitebuilderLuc Pattyn29-Aug-10 12:33 
GeneralRe: ATmega16 simulation Pin
ammeer_a29-Aug-10 12:45
ammeer_a29-Aug-10 12:45 
AnswerRe: ATmega16 simulation Pin
Luc Pattyn29-Aug-10 12:50
sitebuilderLuc Pattyn29-Aug-10 12:50 
GeneralRe: ATmega16 simulation Pin
Dan Neely30-Aug-10 9:50
Dan Neely30-Aug-10 9:50 

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