| #include "board.h" |
| #include <stdbool.h> |
| #include "i2c.h" |
| #include "mcp23017.h" |
| |
| |
| //defines from https://github.com/adafruit/Adafruit-MCP23017-Arduino-Library/blob/master/Adafruit_MCP23017.h under BSD license |
| |
| // registers |
| #define MCP23017_IODIRA 0x00 |
| #define MCP23017_IPOLA 0x02 |
| #define MCP23017_GPINTENA 0x04 |
| #define MCP23017_DEFVALA 0x06 |
| #define MCP23017_INTCONA 0x08 |
| #define MCP23017_IOCONA 0x0A |
| #define MCP23017_GPPUA 0x0C |
| #define MCP23017_INTFA 0x0E |
| #define MCP23017_INTCAPA 0x10 |
| #define MCP23017_GPIOA 0x12 |
| #define MCP23017_OLATA 0x14 |
| |
| |
| #define MCP23017_IODIRB 0x01 |
| #define MCP23017_IPOLB 0x03 |
| #define MCP23017_GPINTENB 0x05 |
| #define MCP23017_DEFVALB 0x07 |
| #define MCP23017_INTCONB 0x09 |
| #define MCP23017_IOCONB 0x0B |
| #define MCP23017_GPPUB 0x0D |
| #define MCP23017_INTFB 0x0F |
| #define MCP23017_INTCAPB 0x11 |
| #define MCP23017_GPIOB 0x13 |
| #define MCP23017_OLATB 0x15 |
| |
| #define MCP23017_INT_ERR 255 |
| |
| |
| //bool i2c_write_byte(bool send_start, bool send_stop, uint8_t byte) |
| //uint8_t i2c_read_byte(bool nack, bool send_stop) |
| //static void i2c_stop_cond(void) |
| |
| int mcp23017_write_byte(uint8_t slave, uint8_t addr, uint8_t byte) |
| { |
| bool nack; |
| |
| WDT_Restart(WDT); |
| |
| // Write slave address |
| nack = i2c_write_byte(true, false, slave << 1); |
| if (nack) |
| goto out_stop; |
| nack = i2c_write_byte(false, false, addr); |
| if (nack) |
| goto out_stop; |
| nack = i2c_write_byte(false, true, byte); |
| if (nack) |
| goto out_stop; |
| |
| out_stop: |
| i2c_stop_cond(); |
| if (nack) |
| return -1; |
| else |
| return 0; |
| } |
| |
| int mcp23017_read_byte(uint8_t slave, uint8_t addr) |
| { |
| bool nack; |
| |
| WDT_Restart(WDT); |
| |
| // dummy write cycle |
| nack = i2c_write_byte(true, false, slave << 1); |
| if (nack) |
| goto out_stop; |
| nack = i2c_write_byte(false, false, addr); |
| if (nack) |
| goto out_stop; |
| // Re-start with read |
| nack = i2c_write_byte(true, false, (slave << 1) | 1); |
| if (nack) |
| goto out_stop; |
| |
| return i2c_read_byte(true, true); |
| |
| out_stop: |
| i2c_stop_cond(); |
| if (nack) |
| return -1; |
| else |
| return 0; |
| } |
| |
| int mcp23017_init(uint8_t slave) |
| { |
| printf("mcp23017_init\n\r"); |
| // all gpio input |
| if (mcp23017_write_byte(slave, MCP23017_IODIRA, 0xff)) |
| return false; |
| // msb of portb output, rest input |
| if (mcp23017_write_byte(slave, MCP23017_IODIRB, 0x7f)) |
| return false; |
| if (mcp23017_write_byte(slave, MCP23017_IOCONA, 0x20)) //disable SEQOP (autoinc addressing) |
| return false; |
| printf("mcp23017 found\n\r"); |
| return true; |
| } |
| |
| int mcp23017_test(uint8_t slave) |
| { |
| printf("mcp23017_test\n\r"); |
| printf("GPIOA 0x%x\n\r", mcp23017_read_byte(slave,MCP23017_GPIOA)); |
| printf("GPIOB 0x%x\n\r", mcp23017_read_byte(slave,MCP23017_GPIOB)); |
| printf("IODIRA 0x%x\n\r", mcp23017_read_byte(slave,MCP23017_IODIRA)); |
| printf("IODIRB 0x%x\n\r", mcp23017_read_byte(slave,MCP23017_IODIRB)); |
| printf("IOCONA 0x%x\n\r", mcp23017_read_byte(slave,MCP23017_IOCONA)); |
| printf("IOCONB 0x%x\n\r", mcp23017_read_byte(slave,MCP23017_IOCONB)); |
| |
| return 0; |
| } |
| |
| int mcp23017_toggle(uint8_t slave) |
| { |
| // example writing MSB of gpio |
| static bool foo=false; |
| if (foo) |
| { |
| printf("+\n\r"); |
| mcp23017_write_byte(slave, MCP23017_OLATB, 0x80); |
| foo=false; |
| } |
| else |
| { |
| printf("-\n\r"); |
| mcp23017_write_byte(slave, MCP23017_OLATB, 0x00); |
| foo=true; |
| } |
| return 0; |
| } |