RE: Corrupt bus messages

Likewise, I just checked some of my old code and found I had also set the RXM bits to '0b11'.  Thankfully I have a number of other checks in place that would stop any potential issues, but in all my time using the MCP2515 I'd never noticed that in the datasheet, so I'm glad you highlighted it.  In fact I wondered if that text was a recent addition, so I checked a copy of the datasheet I downloaded back in 2004 and was surprised to find that that text had indeed been hiding in there all along.

Best Regards,
Jason Turner


From: [email protected] [mailto:[email protected]] On Behalf Of John Dammeyer
Sent: Monday, 4 May 2015 4:13 PM
To: [email protected]
Subject: RE: [CANLIST] Corrupt bus messages

Hi Chuck,
Thanks for the feedback.  You're not the only one.  I dug back into some old code that used the MCP2510 and this is what I found.
// Allow all messages (Std and Ext) into RX0.
      MsgBuf[0] = RXM_OFF+BUKT;
      MCP_cnt = 1;
      MCP_adr = RXB0CTRL;
      MCP_write(channel);

RXM_OFF is defined as 0x60 which is 0b11 just like your example.  Oops!
Most of the time I specific either 11  bit or 29 bit IDs so I'm not using the 0b11 but it's a good warning.
Great Catch!
John Dammeyer