Seed can implementation
Fork of SEEED_CAN by
Diff: seeed_can_spi.cpp
- Revision:
- 0:f5d099885d3d
- Child:
- 2:fd026fcfde94
diff -r 000000000000 -r f5d099885d3d seeed_can_spi.cpp --- /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; +}