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m06e00 ok

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hugo LAMY
2025-03-16 10:43:33 +01:00
parent de938b5377
commit 28f0617e48
3 changed files with 25 additions and 3 deletions
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2
README.md
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@@ -90,5 +90,5 @@ avrdude done. Thank you.
## screen ## screen
- (optional) `export XTERM=xterm` - (optional) `export TERM=xterm`
- `screen /dev/ttyUSB0 115200` - `screen /dev/ttyUSB0 115200`

3
module06/ex00/i2c.c
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@@ -2,7 +2,7 @@
#define TWI_PRESCALE_VALUE 1 // can be 1, 4, 16, 64 #define TWI_PRESCALE_VALUE 1 // can be 1, 4, 16, 64
#define TWI_FREQ 100000UL // 100kHz I2C #define TWI_FREQ 100000UL // 100kHz I2C
#define SLAVE_ADDRESS 42 // 22.3.3 : address 0000000 and 1111xxx are reserved, 42 is 0101010 #define SLAVE_ADDRESS 0x38 // doc AHT20, 7.3 : address of thermistor
void i2c_init(void) { void i2c_init(void) {
TWSR = TWI_PRESCALE_SET(TWI_PRESCALE_VALUE); // 22.9.3 : (Status Register) set prescaler TWSR = TWI_PRESCALE_SET(TWI_PRESCALE_VALUE); // 22.9.3 : (Status Register) set prescaler
@@ -14,7 +14,6 @@ void i2c_start(void) {
while (!(TEST(TWCR, TWINT))); // p225 example code : Wait for TWINT Flag set. This indicates that the START condition has been transmitted while (!(TEST(TWCR, TWINT))); // p225 example code : Wait for TWINT Flag set. This indicates that the START condition has been transmitted
uint8_t status = TWSR & 0b11111000; // Table 22-2. Status codes for Master Transmitter Mode uint8_t status = TWSR & 0b11111000; // Table 22-2. Status codes for Master Transmitter Mode
uart_printstr_itoa_base_endl(status, 2);
if (status != TW_START && status != TW_REP_START) { if (status != TW_START && status != TW_REP_START) {
TWCR = SEND_STOP_CONDITION; TWCR = SEND_STOP_CONDITION;
return; return;

23
module06/ex00/main.c
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@@ -1,11 +1,34 @@
#include "header.h" #include "header.h"
// status before init : 11111000
// status after init : 11111000
// status after start : 1000
// status after stop : 11111000
// description // description
int main() { int main() {
uint8_t status;
uart_init(); uart_init();
status = TWSR & 0b11111000; // Table 22-2. Status codes for Master Transmitter Mode
uart_printstr("status before init : ");
uart_printstr_itoa_base_endl(status, 2);
i2c_init(); i2c_init();
status = TWSR & 0b11111000; // Table 22-2. Status codes for Master Transmitter Mode
uart_printstr("status after init : ");
uart_printstr_itoa_base_endl(status, 2);
i2c_start(); i2c_start();
status = TWSR & 0b11111000; // Table 22-2. Status codes for Master Transmitter Mode
uart_printstr("status after start : ");
uart_printstr_itoa_base_endl(status, 2);
i2c_stop(); i2c_stop();
status = TWSR & 0b11111000; // Table 22-2. Status codes for Master Transmitter Mode
uart_printstr("status after stop : ");
uart_printstr_itoa_base_endl(status, 2);
while(1); while(1);
} }