mcp2515_read_id.c
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1 // ----------------------------------------------------------------------------
2 /*
3  * Copyright (c) 2007 Fabian Greif, Roboterclub Aachen e.V.
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  * notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  * notice, this list of conditions and the following disclaimer in the
13  * documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  *
27  * $Id: mcp2515_read_id.c 7224 2009-01-25 20:19:32Z fabian $
28  */
29 // ----------------------------------------------------------------------------
30 
31 #include "mcp2515_private.h"
32 #ifdef SUPPORT_FOR_MCP2515__
33 
34 // ----------------------------------------------------------------------------
35 // Liest eine ID aus dem Registern des MCP2515 (siehe auch mcp2515_write_id())
36 
37 #if SUPPORT_EXTENDED_CANID
38 
39 uint8_t mcp2515_read_id(uint32_t *id)
40 {
41  uint8_t first;
42  uint8_t tmp;
43 
44  first = spi_putc(0xff);
45  tmp = spi_putc(0xff);
46 
47  if (tmp & (1 << IDE)) {
48  spi_start(0xff);
49 
50  *((uint16_t *) id + 1) = (uint16_t) first << 5;
51  *((uint8_t *) id + 1) = spi_wait();
52  spi_start(0xff);
53 
54  *((uint8_t *) id + 2) |= (tmp >> 3) & 0x1C;
55  *((uint8_t *) id + 2) |= tmp & 0x03;
56 
57  *((uint8_t *) id) = spi_wait();
58 
59  return TRUE;
60  }
61  else {
62  spi_start(0xff);
63 
64  *((uint8_t *) id + 3) = 0;
65  *((uint8_t *) id + 2) = 0;
66 
67  *((uint16_t *) id) = (uint16_t) first << 3;
68 
69  spi_wait();
70  spi_start(0xff);
71 
72  *((uint8_t *) id) |= tmp >> 5;
73 
74  spi_wait();
75 
76  return FALSE;
77  }
78 }
79 
80 #else
81 
82 uint8_t mcp2515_read_id(uint16_t *id)
83 {
84  uint8_t first;
85  uint8_t tmp;
86 
87  first = spi_putc(0xff);
88  tmp = spi_putc(0xff);
89 
90  if (tmp & (1 << IDE)) {
91  spi_putc(0xff);
92  spi_putc(0xff);
93 
94  return 1; // extended-frame
95  }
96  else {
97  spi_start(0xff);
98 
99  *id = (uint16_t) first << 3;
100 
101  spi_wait();
102  spi_start(0xff);
103 
104  *((uint8_t *) id) |= tmp >> 5;
105 
106  spi_wait();
107 
108  if (tmp & (1 << SRR))
109  return 2; // RTR-frame
110  else
111  return 0; // normal-frame
112  }
113 }
114 
115 #endif // SUPPORT_EXTENDED_CANID
116 
117 #endif // SUPPORT_FOR_MCP2515__
TRUE
@ TRUE
Definition: lpc_types.h:50
uavcan::uint32_t
std::uint32_t uint32_t
Definition: std.hpp:26
uavcan::uint16_t
std::uint16_t uint16_t
Definition: std.hpp:25
IDE
#define IDE
Definition: mcp2515_defs.h:296
uavcan::uint8_t
std::uint8_t uint8_t
Definition: std.hpp:24
FALSE
@ FALSE
Definition: lpc_types.h:50
mcp2515_private.h
spi_putc
uint8_t spi_putc(uint8_t data)
Write/read one byte of the SPI interface.
SRR
#define SRR
Bitdefinition von RXBnSIDL (n = 0, 1)
Definition: mcp2515_defs.h:295

uavcan_communicator
Author(s):
autogenerated on Fri Dec 13 2024 03:10:02