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