Diff: seeed_can_spi.cpp

Revision:

0:f5d099885d3d

Child:

2:fd026fcfde94

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/seeed_can_spi.cpp	Tue Nov 05 22:37:35 2013 +0000
@@ -0,0 +1,149 @@
+/* seeed_can_spi.cpp
+ * Copyright (c) 2013 Sophie Dexter
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+ 
+#include "seeed_can_spi.h"
+
+/** reset the MCP2515
+ */
+void mcpReset(can_t *obj)
+{
+    obj->ncs = 0;
+    obj->spi.write(MCP_RESET);
+    obj->ncs = 1;
+    wait_ms(10);
+}
+
+/** read from a single MCP2515 register
+ */
+uint8_t mcpRead(can_t *obj, const uint8_t address)
+{
+    uint8_t result;
+
+    obj->ncs = 0;
+    obj->spi.write(MCP_READ);
+    obj->spi.write(address);
+    result = obj->spi.write(0x00);
+    obj->ncs = 1;
+    return result;
+}
+
+/** read multiple MCP2515 registers sequentially into an array (relies on address auto-increment)
+ */
+void mcpReadMultiple(can_t *obj, const uint8_t address, uint8_t values[], const uint8_t n)
+{
+    obj->ncs = 0;
+    obj->spi.write(MCP_READ);
+    obj->spi.write(address);
+    for (uint32_t i=0; i<n; i++) {
+        values[i] = obj->spi.write(0x00);
+    }
+    obj->ncs = 1;
+}
+
+/** read the specified MCP2515 receive buffer into an array (needs one fewer SPI transfer than mcpReadMultiple)
+ */
+void mcpReadBuffer(can_t *obj, const uint8_t command, uint8_t values[], const uint8_t n)
+{
+    obj->ncs = 0;
+    obj->spi.write(command);
+    for (uint32_t i=0; i<n; i++) {
+        values[i] = obj->spi.write(0x00);
+    }
+    obj->ncs = 1;
+}
+
+/**  write to a single MCP2515 register
+ */
+void mcpWrite(can_t *obj, const uint8_t address, const uint8_t value)
+{
+    obj->ncs = 0;
+    obj->spi.write(MCP_WRITE);
+    obj->spi.write(address);
+    obj->spi.write(value);
+    obj->ncs = 1;
+}
+
+/** write to multiple MCP2515 registers consecutively from an array
+ */
+void mcpWriteMultiple(can_t *obj, const uint8_t address, const uint8_t values[], const uint8_t n)
+{
+    obj->ncs = 0;
+    obj->spi.write(MCP_WRITE);
+    obj->spi.write(address);
+    for (uint32_t i=0; i<n; i++) {
+        obj->spi.write(values[i]);
+    }
+    obj->ncs = 1;
+}
+
+/** write to the specified MCP2515 transmit buffer from an array (needs one fewer SPI transfer than mcpWriteMultiple)
+ */
+void mcpWriteBuffer(can_t *obj, const uint8_t command, uint8_t values[], const uint8_t n)
+{
+    obj->ncs = 0;
+    obj->spi.write(command);
+    for (uint32_t i=0; i<n; i++) {
+        obj->spi.write(values[i]);
+    }
+    obj->ncs = 1;
+}
+
+/** initiate transmission of the specified MCP2515 transmit buffer
+ */
+void mcpBufferRTS(can_t *obj, const uint8_t command)
+{
+    obj->ncs = 0;
+    obj->spi.write(command);
+    obj->ncs = 1;
+}
+
+/**  read mcp2515's status register
+ */
+uint8_t mcpStatus(can_t *obj)
+{
+    uint8_t status;
+
+    obj->ncs = 0;
+    obj->spi.write(MCP_READ_STATUS);
+    status = obj->spi.write(0x00);
+    obj->ncs = 1;
+    return status;
+}
+
+/**  read mcp2515's receive status register
+ */
+uint8_t mcpReceiveStatus(can_t *obj)
+{
+    uint8_t status;
+
+    obj->ncs = 0;
+    obj->spi.write(MCP_RX_STATUS);
+    status = obj->spi.write(0x00);
+    obj->ncs = 1;
+    return status;
+}
+
+/** modify bits of a register specified by a mask
+ */
+void mcpBitModify(can_t *obj, const uint8_t address, const uint8_t mask, const uint8_t data)
+{
+    obj->ncs = 0;
+    obj->spi.write(MCP_BITMOD);
+    obj->spi.write(address);
+    obj->spi.write(mask);
+    obj->spi.write(data);
+    obj->ncs = 1;
+}