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2009-01-05 by Brian
What is the common comms method to use to commuicate between AVR's (mega series) for short distances (USART, SPI, IIC, CAN), a few inches to less than a couple of feet (not on the same board)? This could be for 2 or more AVR's. I am using IIC for my eeprom and RTC. Brian
2009-01-06 by John Samperi
At 11:33 AM 6/01/2009, you wrote: >a few inches >to less than a couple of feet (not on the same board)? This could be >for 2 or more AVR's. I am using IIC for my eeprom and RTC. Once you go off board you should have buffers. As you are already using I2C you could get some buffers for that which will extend the buss considerably. This is provided you don't need huge data transfers at high speed in which case a buffered SPI buss may be better. Regards John Samperi ******************************************************** Ampertronics Pty. Ltd. 11 Brokenwood Place Baulkham Hills, NSW 2153 AUSTRALIA Tel. (02) 9674-6495 Fax (02) 9674-8745 Website http://www.ampertronics.com.au *Electronic Design * Custom Products * Contract Assembly ********************************************************
2009-01-06 by Julian Higginson
What kind of network topology? If you can work out a way to do point-to-point I'd go USARTS if you have at least one spare on each AVR. Nice and simple to use, and opens up all sorts of other comms options if you want. As John said, if you're going off-board, buffered signals are important. Use standard RS232 chips. Or if you want something a bit more fancy - maybe try using the USARTS with infrared transmitters/receivers? Julian Higginson Bruttour International P/L http://www.bruttour.com.au Ph: +612 9987 1581
-----Original Message----- From: AVR-Chat@yahoogroups.com [mailto:AVR-Chat@yahoogroups.com] On Behalf Of Brian Sent: Tuesday, 6 January 2009 11:34 AM To: AVR-Chat@yahoogroups.com Subject: [AVR-Chat] Comms between AVR's What is the common comms method to use to commuicate between AVR's (mega series) for short distances (USART, SPI, IIC, CAN), a few inches to less than a couple of feet (not on the same board)? This could be for 2 or more AVR's. I am using IIC for my eeprom and RTC. Brian ------------------------------------ Yahoo! Groups Links
2009-01-06 by Julian Higginson
Of course, with the infrared, you also can move away from point to point and have much more flexibility in data addressing to and from different units, too (if you want to spend time making your own basic data transport layer) Also... a wired option for multiple listeners/responders to a message is RS485 (again, you might want some kind of transport layer in the communications section of your firmware) Julian Higginson Bruttour International P/L http://www.bruttour.com.au Ph: +612 9987 1581
-----Original Message----- From: AVR-Chat@yahoogroups.com [mailto:AVR-Chat@yahoogroups.com] On Behalf Of Julian Higginson Sent: Tuesday, 6 January 2009 1:08 PM To: AVR-Chat@yahoogroups.com Subject: RE: [AVR-Chat] Comms between AVR's What kind of network topology? If you can work out a way to do point-to-point I'd go USARTS if you have at least one spare on each AVR. Nice and simple to use, and opens up all sorts of other comms options if you want. As John said, if you're going off-board, buffered signals are important. Use standard RS232 chips. Or if you want something a bit more fancy - maybe try using the USARTS with infrared transmitters/receivers? Julian Higginson Bruttour International P/L http://www.bruttour.com.au Ph: +612 9987 1581 -----Original Message----- From: AVR-Chat@yahoogroups.com [mailto:AVR-Chat@yahoogroups.com] On Behalf Of Brian Sent: Tuesday, 6 January 2009 11:34 AM To: AVR-Chat@yahoogroups.com Subject: [AVR-Chat] Comms between AVR's What is the common comms method to use to commuicate between AVR's (mega series) for short distances (USART, SPI, IIC, CAN), a few inches to less than a couple of feet (not on the same board)? This could be for 2 or more AVR's. I am using IIC for my eeprom and RTC. Brian ------------------------------------ Yahoo! Groups Links ------------------------------------ Yahoo! Groups Links
2009-01-06 by leon Heller
----- Original Message -----
From: "Brian" <blue_eagle74@yahoo.com> To: <AVR-Chat@yahoogroups.com> Sent: Tuesday, January 06, 2009 12:33 AM Subject: [AVR-Chat] Comms between AVR's > What is the common comms method to use to commuicate between AVR's > (mega series) for short distances (USART, SPI, IIC, CAN), a few inches > to less than a couple of feet (not on the same board)? This could be > for 2 or more AVR's. I am using IIC for my eeprom and RTC. I'd use SPI, it's faster than RS-232 and I2C. OTOH, it might be best to stick to I2C if you don't have the SPI available and have to do it in software. Leon
2009-01-06 by Steven Hodge
I'm confused. The OP only said a few inches to a vague less than a couple of feet. I can easily envision a single board where the path length is "a few inches", and thus it would seem unnecessary to insert buffers or whatever just because the "few inches" had an off-board segment. I'm faced with the same situation, although only distances of up to maybe a foot or so, so could someone please give an answer based on distance rather than one that came across to me as just blind adherence to an on/off-the-bus, er, board, rule. Or, alternately, explain exactly why an off-board segment of just a few inches demands buffering or such. Thanks, Steve
From: AVR-Chat@yahoogroups.com [mailto:AVR-Chat@yahoogroups.com] On Behalf Of Julian Higginson Sent: Monday, January 05, 2009 9:01 PM To: AVR-Chat@yahoogroups.com Subject: RE: [AVR-Chat] Comms between AVR's Of course, with the infrared, you also can move away from point to point and have much more flexibility in data addressing to and from different units, too (if you want to spend time making your own basic data transport layer) Also... a wired option for multiple listeners/responders to a message is RS485 (again, you might want some kind of transport layer in the communications section of your firmware) Julian Higginson Bruttour International P/L http://www.bruttour.com.au Ph: +612 9987 1581 -----Original Message----- From: AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com> [mailto:AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com> ] On Behalf Of Julian Higginson Sent: Tuesday, 6 January 2009 1:08 PM To: AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com> Subject: RE: [AVR-Chat] Comms between AVR's What kind of network topology? If you can work out a way to do point-to-point I'd go USARTS if you have at least one spare on each AVR. Nice and simple to use, and opens up all sorts of other comms options if you want. As John said, if you're going off-board, buffered signals are important. Use standard RS232 chips. Or if you want something a bit more fancy - maybe try using the USARTS with infrared transmitters/receivers? Julian Higginson Bruttour International P/L http://www.bruttour.com.au Ph: +612 9987 1581 -----Original Message----- From: AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com> [mailto:AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com> ] On Behalf Of Brian Sent: Tuesday, 6 January 2009 11:34 AM To: AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com> Subject: [AVR-Chat] Comms between AVR's What is the common comms method to use to commuicate between AVR's (mega series) for short distances (USART, SPI, IIC, CAN), a few inches to less than a couple of feet (not on the same board)? This could be for 2 or more AVR's. I am using IIC for my eeprom and RTC. Brian ------------------------------------ Yahoo! Groups Links ------------------------------------ Yahoo! Groups Links __________ Information from ESET Smart Security, version of virus signature database 3741 (20090105) __________ The message was checked by ESET Smart Security. http://www.eset.com [Non-text portions of this message have been removed]