diff --git a/i2c/i2c.c b/i2c/i2c.c new file mode 100644 index 0000000..ee5af6c --- /dev/null +++ b/i2c/i2c.c @@ -0,0 +1,60 @@ +/* +Copyright 2022, Savanni D'Gerinel + +This file is part of Savanni's AVR library. + +This AVR library is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. + +This AVR library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. + +You should have received a copy of the GNU General Public License along with this AVR library. If not, see . +*/ + +#include +#include "i2c.h" + +void i2c_init_host(i2c_host_t *bus, i2c_error_e *error) { + dio_set_direction(&bus->sda, LINE_OUT); + dio_set(&bus->sda, 1); + + dio_set_direction(&bus->scl, LINE_OUT); + dio_set(&bus->scl, 1); +} + +void i2c_init_client(i2c_client_t *bus, i2c_error_e *error) { + dio_set_direction(&bus->sda, LINE_IN); + dio_set_direction(&bus->scl, LINE_IN); +} + +void i2c_host_write_packet(i2c_host_t *bus, uint8_t value, i2c_error_e *error) { + dio_set(&bus->sda, 0); + dio_set(&bus->scl, 0); + + for (int i = 7; i >= 0; i--) { + dio_set(&bus->sda, value & _BV(i)); + /* + if (value & _BV(i)) { + dio_set(&bus->sda, 1); + } else { + dio_set(&bus->sda, 0); + } + */ + dio_set(&bus->scl, 1); + dio_set(&bus->scl, 0); + } + + dio_set_direction(&bus->scl, LINE_IN); + +} + +void i2c_host_write(i2c_host_t *bus, uint8_t address, uint8_t *data, size_t length, i2c_error_e *error) { + if (*error) return; + + i2c_host_write_packet(bus, address << 1, error); + if (*error != ok) return; + + for (int i = 0; i < length; i++) { + i2c_host_write_packet(bus, data[i], error); + if (*error != ok) return; + } +} diff --git a/i2c/i2c.h b/i2c/i2c.h new file mode 100644 index 0000000..520851c --- /dev/null +++ b/i2c/i2c.h @@ -0,0 +1,39 @@ +/* +Copyright 2022, Savanni D'Gerinel + +This file is part of Savanni's AVR library. + +This AVR library is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. + +This AVR library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. + +You should have received a copy of the GNU General Public License along with this AVR library. If not, see . +*/ + +#ifndef __I2C_H__ +#define __I2C_H__ + +#include + +typedef enum { + ok, + nak +} i2c_error_e; + +typedef struct { + dio_t sda; + dio_t clk; +} i2c_host_t; + +typedef struct { + dio_t sda; + dio_t clk; + uint8_t addr; +} + +void i2c_init_host(i2c_host_t *, i2c_error_e *); +void i2c_init_client(i2c_client_t *, i2c_error_e *); + +void i2c_host_write(i2c_host_t *, uint8_t, uint8_t, size_t, i2c_error_e); + +#endif