Post Created date
Byte + Byte = int
Does AVR GCC treat (byte_2 << 8) as a uint before shifting or does it require a cast to a uint before shifting? Dave Raymond
Friday, 21 May 2010 - 18:03
Atmega162 with SJA1000 controller, help please!!!
A single CAN node cannot operate as a bus since every message has to be acknowledged by another node. The SJA1000 will continue to try to send a single message over and over until...
Tuesday, 2 February 2010 - 19:51
Atmega162 with SJA1000 controller, help please!!!
The SJA1000 has its own address/data demultiplexer, so it is a simple matter to interface the Mega162 directly to this chip. Connect AD lines, rd*, wr*, and ale directly. Choose a...
Monday, 25 January 2010 - 22:25
A problem of SJA1000 controlled by ATMega128
Your circuit looks OK to me, although we ground RX1 and I can't comment on the output interface. Because you use PORTC for another function, I would recommend adding the line...
Monday, 4 January 2010 - 22:04
A problem of SJA1000 controlled by ATMega128
We have many successful installations of one or more SJA1000's with Mega128's and Mega64's. Connecting these devices to the processor is not trivial. We use the external memory...
Wednesday, 30 December 2009 - 22:33
Need help with CAN bus
Honda uses 29-bit CAN starting in 2006. The Jeep Patriot uses 11-bit CAN starting in 2007. CARB requires that all vehicles use 500 kbaud on OBD. Dave Raymond
Friday, 23 October 2009 - 15:34
HELP - Sending one simple message on CAN bus
The first requirement for a CAN channel to work is that there must be two devices on the bus talking to each other. One is not sufficient. The second is required to acknowledge...
Tuesday, 29 September 2009 - 21:25
Why can't array subscript be char?
if (scratch = timer_seconds(TMR_CLOSE_RUN)) I use this format to avoid warnings and time penalties: if ((scratch = timer_seconds(TMR_CLOSE_RUN)) != 0) Dave Raymond
Wednesday, 16 September 2009 - 18:46
Write asm in C with the ICCAVR compiler
To add a sqrt function in assembler to an ICCACR project simply create a .s file with the function in assembler. There is no need to use embedded assembly and very little wrapping...
Thursday, 30 July 2009 - 17:34
Change interrupt handler at runtime
A single variable that can be tested to choose between two program paths should be more efficient than function pointers in both speed and size. Dave Raymond
Tuesday, 21 July 2009 - 19:12
to CAN bus or not?
Quote:1. Does anyone ever program CAN buss in assembler? (Honest, I'm not trying to start another war). 2. Is there a really cheap, low baud rate device with built in CAN bus I...
Friday, 19 June 2009 - 19:11
Trouble reading input port
PINB & 0xC0 can never equal 1. It can equal 0, 0x40, 0x80, or 0xc0. Does this help? Dave Raymond
Friday, 19 June 2009 - 18:53