better i2c protocol implentation

This commit is contained in:
2026-02-20 13:51:44 +01:00
parent c1164145e9
commit 63c7bd5640

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@@ -937,131 +937,173 @@ uint8_t crc8(const uint8_t *data, size_t len) {
return crc;
}
bool execute_pc_command(uint8_t *data, uint8_t *&p, uint8_t *output, uint8_t len, uint32_t* baud_change) {
switch (data[0]) {
case 0: { // Set clock
if(len < 5) {
*p++ = 2;
return true;
}
uint32_t clock = ((uint32_t)data[1] << 24) | ((uint32_t)data[2] << 16) | ((uint32_t)data[3] << 8) | ((uint32_t)data[4]);
Wire.setClock(clock);
} break;
case 1: { // Send data
if(len < 3) {
*p++ = 2;
return true;
}
Wire.beginTransmission(data[1]);
Wire.write(data + 2, len - 2);
auto out = Wire.endTransmission();
*p++ = out;
} break;
case 2: { // Send and receive data
if(len < 4) {
*p++ = 2;
return true;
}
uint8_t addr = data[1];
uint8_t datalen = data[2];
if(len < 3 + datalen + 1) {
*p++ = 2;
return true;
}
Wire.beginTransmission(addr);
Wire.write(data + 3, datalen);
auto out = Wire.endTransmission(false);
uint8_t recvlen = Wire.requestFrom(addr, data[3+datalen]);
if ((p - output) + recvlen >= sizeof(output)) {
*p++ = 2;
return true;
}
*p++ = out;
while(Wire.available()) *p++ = Wire.read();
} break;
case 3: { // Quit
i2c_pc_control = false;
MuteScreen(false);
*baud_change = 115200;
} break;
case 4: { // Version
*p++ = 3;
} break;
case 5: { // Reboot
Serial.write(1);
Serial.write(5);
Serial.flush();
esp_restart();
} break;
case 6: { // Change baud
if(len < 5) {
*p++ = 2;
return true;
}
*baud_change = ((uint32_t)data[1] << 24) | ((uint32_t)data[2] << 16) |
((uint32_t)data[3] << 8) | ((uint32_t)data[4]);
} break;
case 7: { // Write to EEPROM
if(len < 4) {
*p++ = 2;
return true;
}
EEPROM.writeBytes((data[1] << 8) | data[2], data + 3, len - 3);
EEPROM.commit();
} break;
case 8: { // Read from EEPROM
if(len < 4) {
*p++ = 2;
return true;
}
auto address = (data[1] << 8) | data[2];
*p++ = data[3] + 1;
*p++ = 8;
for(uint16_t i = 0; i < data[3]; i++) *p++ = EEPROM.read(address + i);
} break;
case 0xfd: { // Get EEPROM address for userdata
*p++ = (uint8_t)(EE_START_CONTROLMODE_DATA >> 8);
*p++ = EE_START_CONTROLMODE_DATA & 0xff;
*p++ = (uint8_t)(EE_LEN_CONTROLMODE_DATA >> 8);
*p++ = EE_LEN_CONTROLMODE_DATA & 0xff;
} break;
case 0xfe: { // Get EEPROM address for starting control mode on boot
*p++ = (uint8_t)(EE_BYTE_CONTROLMODE >> 8);
*p++ = EE_BYTE_CONTROLMODE & 0xff;
} break;
case 0xff:
break;
default:
*p++ = 3;
return true;
}
return false;
}
void total_pc_control() {
static uint8_t data[127];
static uint8_t output[257];
uint8_t *p = output + 2;
uint32_t baud_change = 0;
bool error = false;
bool done = false;
bool send_crc = false;
if(i2c_pc_control_init) {
Serial.write(1);
Serial.write(0xff);
Serial.flush();
error = true;
done = true;
i2c_pc_control_init = false;
}
if(Serial.available()) {
if(Serial.available() && !done) {
uint8_t userlen = Serial.read();
if (userlen == 0) return;
if(Serial.available() && userlen == '~' && Serial.peek() == '/') {
Serial.read();
Serial.write(1);
Serial.write(0xff);
Serial.flush(true);
if (userlen == 0) {
Serial.flush();
return;
}
bool has_crc = (userlen >> 7) == 1;
uint8_t orig_userlen = userlen;
userlen &= 127;
if(Serial.available() && userlen == '~' && Serial.peek() == '/') {
Serial.read();
error = true;
done = true;
}
auto len = Serial.read(data, userlen);
if(len != userlen) return;
if(!done) {
bool has_crc = (userlen >> 7) == 1;
send_crc = has_crc;
uint8_t orig_userlen = userlen;
userlen &= 127;
if(has_crc && Serial.available()) {
uint8_t crc = Serial.read();
uint8_t expected_crc = 0;
expected_crc = crc8_update(expected_crc, orig_userlen);
for (int i = 0; i < len; i++) expected_crc = crc8_update(expected_crc, data[i]);
if(crc != expected_crc) {
Serial.write(0x02);
Serial.write(0xFF);
Serial.write(0x01);
Serial.flush();
return;
auto len = Serial.read(data, userlen);
if(len != userlen) {
error = true;
*p++ = 0;
}
if(has_crc && Serial.available()) {
uint8_t crc = Serial.read();
uint8_t expected_crc = 0;
expected_crc = crc8_update(expected_crc, orig_userlen);
for (int i = 0; i < len; i++) expected_crc = crc8_update(expected_crc, data[i]);
if(crc != expected_crc) {
error = true;
send_crc = false;
*p++ = 1;
}
}
if(!error) error = execute_pc_command(data, p, output, len, &baud_change);
done = true;
}
}
switch (data[0]) {
case 0: { // Set clock
if(len < 5) return;
uint32_t clock = ((uint32_t)data[1] << 24) | ((uint32_t)data[2] << 16) | ((uint32_t)data[3] << 8) | ((uint32_t)data[4]);
Wire.setClock(clock);
} break;
case 1: { // Send data
if(len < 3) return;
Wire.beginTransmission(data[1]);
Wire.write(data + 2, len - 2);
auto out = Wire.endTransmission();
*p++ = out;
} break;
case 2: { // Send and receive data
if(len < 4) return; // Need at least: cmd, addr, datalen, recvlen
uint8_t addr = data[1];
uint8_t datalen = data[2];
if(len < 3 + datalen + 1) return; // Validate buffer size
Wire.beginTransmission(addr);
Wire.write(data + 3, datalen);
auto out = Wire.endTransmission(false);
uint8_t recvlen = Wire.requestFrom(addr, data[3+datalen]);
if ((p - output) + recvlen >= sizeof(output)) return;
*p++ = out;
while(Wire.available()) *p++ = Wire.read();
} break;
case 3: { // Quit
i2c_pc_control = false;
MuteScreen(false);
baud_change = 115200;
} break;
case 4: { // Version
*p++ = 2;
} break;
case 5: { // Reboot
Serial.write(1);
Serial.write(5);
Serial.flush();
esp_restart();
} break;
case 6: { // Change baud
if(len < 5) return;
baud_change = ((uint32_t)data[1] << 24) | ((uint32_t)data[2] << 16) |
((uint32_t)data[3] << 8) | ((uint32_t)data[4]);
} break;
case 7: { // Write to EEPROM
if(len < 4) return;
EEPROM.writeBytes((data[1] << 8) | data[2], data + 3, len - 3);
EEPROM.commit();
} break;
case 8: { // Read from EEPROM
if(len < 4) return;
auto address = (data[1] << 8) | data[2];
*p++ = data[3] + 1;
*p++ = 8;
for(uint16_t i = 0; i < data[3]; i++) *p++ = EEPROM.read(address + i);
} break;
case 0xfd: { // Get EEPROM address for userdata
*p++ = (uint8_t)(EE_START_CONTROLMODE_DATA >> 8);
*p++ = EE_START_CONTROLMODE_DATA & 0xff;
*p++ = (uint8_t)(EE_LEN_CONTROLMODE_DATA >> 8);
*p++ = EE_LEN_CONTROLMODE_DATA & 0xff;
} break;
case 0xfe: { // Get EEPROM address for starting control mode on boot
*p++ = (uint8_t)(EE_BYTE_CONTROLMODE >> 8);
*p++ = EE_BYTE_CONTROLMODE & 0xff;
} break;
case 0xff:
default:
break;
}
if(done) {
output[0] = (p - output) - 1;
output[1] = data[0];
if(has_crc) {
if(error) output[1] = 0xff;
else output[1] = data[0];
if(send_crc) {
output[0] |= 0x80;
uint8_t crc = crc8(output, p - output);
*p++ = crc;
@@ -1075,6 +1117,6 @@ void total_pc_control() {
baud_change = 0;
}
Serial.flush(true);
Serial.flush(!error);
}
}