first version of m06e01

module06/ex01/main.c

@@ -0,0 +1,68 @@
+#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);
+}