#include "header.h" // sqtatus codes : // -- Master -- // TW_BUS_ERROR 0x00 = 0b0 = 0 -> illegal start or stop condition // TW_START 0x08 = 0b1000 = 8 -> start condition transmitted // TW_REP_START 0x10 = 0b10000 = 16 -> repeated start condition transmitted // -- Master Transmitter -- // TW_MT_SLA_ACK 0x18 = 0b11000 = 24 -> SLA+W transmitted, ACK received // TW_MT_SLA_NACK 0x20 = 0b100000 = 32 -> SLA+W transmitted, NACK received // TW_MT_DATA_ACK 0x28 = 0b101000 = 40 -> data transmitted, ACK received // TW_MT_DATA_NACK 0x30 = 0b110000 = 48 -> data transmitted, NACK received // TW_MT_ARB_LOST 0x38 = 0b111000 = 56 -> arbitration lost in SLA+W or data // -- Master Receiver -- // TW_MR_ARB_LOST 0x38 = 0b111000 = 56 -> arbitration lost in SLA+R or NACK // TW_MR_SLA_ACK 0x40 = 0b1000000 = 64 -> SLA+R transmitted, ACK received // TW_MR_SLA_NACK 0x48 = 0b1001000 = 72 -> SLA+R transmitted, NACK received // TW_MR_DATA_ACK 0x50 = 0b1010000 = 80 -> data received, ACK returned // TW_MR_DATA_NACK 0x58 = 0b1011000 = 88 -> data received, NACK returned // TW_ST_SLA_ACK 0xA8 = 0b10101000 = 168 -> SLA+R received, ACK returned // TW_NO_INFO 0xF8 = 0b11111000 = 248 -> no state information available #define SLAVE_ADDRESS 0x38 // doc AHT20, 7.3 : address of thermistor void print_hex_value(char c) {} void print_status(char *str) { uint8_t status; status = TWSR & 0b11111000; // Table 22-2. Status codes for Master Transmitter Mode uart_printstr(str); uart_printstr(" : "); uart_printstr_itoa_base_endl(status, 2); } // description int main() { uart_init(); print_status("before init"); i2c_init(); print_status("after init"); i2c_start(); print_status("after start"); i2c_send_addr_w(SLAVE_ADDRESS); print_status("after SLA+W"); i2c_write('t'); print_status("after write t"); i2c_write('e'); print_status("after write e"); i2c_write('e'); print_status("after write e"); i2c_write('a'); print_status("after write a"); i2c_write('t'); print_status("after write t"); i2c_stop(); print_status("after stop"); while(1); }