# B15F: drv/usart.cpp Source File

usart.cpp
#include "usart.h"
void USART::openDevice(std::string device)
{
file_desc = open(device.c_str(), O_RDWR | O_NOCTTY | O_NDELAY /* | O_NONBLOCK*/);
if(file_desc <= 0)
throw USARTException("Fehler beim Öffnen des Gerätes");
struct termios options;
int code = tcgetattr(file_desc, &options);
if(code)
throw USARTException("Fehler beim Lesen der Geräteparameter");
options.c_cflag = CS8 | CLOCAL | CREAD;
options.c_iflag = IGNPAR;
options.c_oflag = 0;
options.c_lflag = 0;
options.c_cc[VMIN] = 0; // #bytes read returns at least
options.c_cc[VTIME] = timeout;
code = cfsetspeed(&options, baudrate);
if(code)
throw USARTException("Fehler beim Setzen der Baudrate");
code = tcsetattr(file_desc, TCSANOW, &options);
if(code)
throw USARTException("Fehler beim Setzen der Geräteparameter");
clearOutputBuffer();
clearInputBuffer();
}
void USART::closeDevice()
{
int code = close(file_desc);
if(code)
throw USARTException("Fehler beim Schließen des Gerätes");
}
void USART::clearInputBuffer()
{
int code = tcflush(file_desc, TCIFLUSH);
if(code)
throw USARTException("Fehler beim Leeren des Eingangspuffers");
}
void USART::clearOutputBuffer()
{
int code = tcflush(file_desc, TCOFLUSH);
if(code)
throw USARTException("Fehler beim Leeren des Ausgangspuffers");
}
void USART::flushOutputBuffer()
{
int code = tcdrain(file_desc);
if(code)
throw USARTException("Fehler beim Versenden des Ausgangspuffers");
}
void USART::printStatistics()
{
double pz = 1e2 * n_blocks_failed / n_blocks_total;
pz = std::round(pz * 1e2) / 1e2;
std::cout << "blocks total: " << n_blocks_total << " ok: " << (n_blocks_total - n_blocks_failed) << " failed: " << n_blocks_failed << " (" << pz << "%)" << std::endl;
}
void USART::writeByte(uint8_t b)
{
int sent = write(file_desc, &b, 1);
if(sent != 1)
{
std::cout << "WARNUNG: Fehler beim Senden (" << sent << "): writeByte(), wiederhole..." << std::endl;
usleep(100000);
sent = write(file_desc, &b, 1);
if(sent != 1)
throw USARTException("Fehler beim Senden: writeByte()");
}
}
void USART::writeInt(uint16_t d)
{
int sent = write(file_desc, reinterpret_cast<char*>(&d), 2);
if(sent != 2)
throw USARTException("Fehler beim Senden: writeInt()");
}
int USART::read_timeout(uint8_t* buffer, uint16_t offset, uint8_t len, uint32_t timeout)
{
uint32_t elapsed = 0;
int n_read = -1;
auto start = std::chrono::steady_clock::now();
auto end = start;
while(elapsed < timeout)
{
n_read = read(file_desc, buffer + offset, len);
if (n_read == len)
return n_read;
end = std::chrono::steady_clock::now();
elapsed = std::chrono::duration_cast<std::chrono::microseconds>(end - start).count();
}
return 0;
}
int USART::write_timeout(uint8_t* buffer, uint16_t offset, uint8_t len, uint32_t timeout)
{
uint32_t elapsed = 0;
int n_sent = -1;
auto start = std::chrono::steady_clock::now();
auto end = start;
while(elapsed < timeout)
{
n_sent = write(file_desc, buffer + offset, len);
flushOutputBuffer();
if (n_sent == len)
return n_sent;
end = std::chrono::steady_clock::now();
elapsed = std::chrono::duration_cast<std::chrono::microseconds>(end - start).count();
}
return n_sent;
}
void USART::writeBlock(uint8_t* buffer, uint16_t offset, uint8_t len)
{
uint8_t crc;
uint8_t aw;
const uint16_t us_per_bit = (1000000 / baudrate) * 16;
const uint16_t n_total = len + 3;
n_blocks_total++;
bool failed = false;
do
{
// calc crc
crc = 0;
for(uint8_t i = 0; i < len; i++)
{
crc ^= buffer[i];
for (uint8_t k = 0; k < 8; k++)
{
if (crc & 1)
crc ^= CRC7_POLY;
crc >>= 1;
}
}
// construct block
block_buffer[0] = len;
std::memcpy(&block_buffer[1], buffer + offset, len);
block_buffer[len + 1] = crc;
block_buffer[len + 2] = BLOCK_END;
// send block
clearOutputBuffer();
clearInputBuffer();
int n_sent = write_timeout(&block_buffer[0], 0, len + 3, us_per_bit * n_total);
if(n_sent != n_total)
throw std::runtime_error("fatal (send): " + std::to_string(n_sent));
/*for(uint8_t i = 0; i < len + 3; i++)
{
write_timeout(&block_buffer[i], 0, 1, us_per_bit * n_total);
//tcdrain(file_desc);
//usleep(1000);
}*/
// flush output data
tcdrain(file_desc);
//usleep(us_per_bit * n_total * 10);
// check response
int n_read = read_timeout(&aw, 0, 1, us_per_bit * n_blocks_total * 10);
for(uint16_t i = 0; i < 255 && n_read != 1; i++)
{
writeByte(0x80); // Stoppzeichen für Block
if(tcdrain(file_desc))
{
std::cout << "drain failed" << std::endl;
}
std::cout << "WARNING: read error (" << n_read << "), retry #" << (int) i << std::endl;
usleep(us_per_bit*100);
n_read = read_timeout(&aw, 0, 1, us_per_bit);
}
if(n_read != 1)
throw std::runtime_error("fatal: " + std::to_string(n_read));
//clearInputBuffer();
if(aw != 0xFF) {
if(!failed)
n_blocks_failed++;
failed = true;
std::cout << "block failed, retry" << std::endl;
}
}
while(aw != 0xFF);
//std::cout << "OK" << std::endl;
}
uint8_t USART::readByte(void)
{
char b;
auto start = std::chrono::steady_clock::now();
auto end = start;
uint16_t elapsed = 0;
while(elapsed < timeout * 100)
{
int code = read(file_desc, &b, 1);
if (code > 0)
return static_cast<uint8_t>(b);
end = std::chrono::steady_clock::now();
elapsed = std::chrono::duration_cast<std::chrono::milliseconds>(end - start).count();
}
throw TimeoutException("Verbindung unterbrochen.", timeout);
}
uint16_t USART::readInt(void)
{
return readByte() | readByte() << 8;
}
bool USART::readBlock(uint8_t* buffer, uint16_t offset)
{
uint8_t len = readByte();
uint8_t crc = 0;
buffer += offset;
uint32_t block_timeout = timeout / 10;
// wait for block
int n_ready;
uint16_t elapsed = 0;
auto start = std::chrono::steady_clock::now();
auto end = start;
while(elapsed < block_timeout)
{
int code = ioctl(file_desc, FIONREAD, &n_ready);
if(code != 0)
{
std::cout << "n_ready code: " << code << std::endl;
return false;
}
if(n_ready >= len + 1)
break;
end = std::chrono::steady_clock::now();
elapsed = std::chrono::duration_cast<std::chrono::milliseconds>(end - start).count();
}
if(elapsed >= timeout)
{
std::cout << "block timeout: " << std::endl;
return false;
}
while(len--)
{
*buffer = readByte();
crc ^= *buffer++;
for (uint8_t i = 0; i < 8; i++)
{
if (crc & 1)
crc ^= CRC7_POLY;
crc >>= 1;
}
}
crc ^= readByte();
for (uint8_t i = 0; i < 8; i++)
{
if (crc & 1)
crc ^= CRC7_POLY;
crc >>= 1;
}
if(TEST == 1)
crc = 1;
if(TEST > 100)
TEST = 0;
if (crc == 0)
{
writeByte(0xFF);
return true;
}
else
{
writeByte(0xFE);
return false;
}
}
uint32_t USART::getBaudrate()
{
return baudrate;
}
uint8_t USART::getTimeout()
{
return timeout;
}
void USART::setBaudrate(uint32_t baudrate)
{
this->baudrate = baudrate;
}
void USART::setTimeout(uint8_t timeout)
{
this->timeout = timeout;
}
USART::getBaudrate
uint32_t getBaudrate(void)
Definition: usart.cpp:306
USART::readByte
uint8_t readByte(void)
Definition: usart.cpp:210
USARTException
Definition: usartexception.h:9
USART::printStatistics
void printStatistics(void)
Definition: usart.cpp:60
USART::closeDevice
void closeDevice(void)
Definition: usart.cpp:32
USART::clearInputBuffer
void clearInputBuffer(void)
Definition: usart.cpp:39
USART::getTimeout
uint8_t getTimeout(void)
Definition: usart.cpp:311
USART::clearOutputBuffer
void clearOutputBuffer(void)
Definition: usart.cpp:46
USART::setBaudrate
void setBaudrate(uint32_t baudrate)
Definition: usart.cpp:316
USART::writeByte
void writeByte(uint8_t b)
Definition: usart.cpp:67
USART::openDevice
void openDevice(std::string device)
Definition: usart.cpp:3
USART::readInt
uint16_t readInt(void)
Definition: usart.cpp:229
USART::setTimeout
void setTimeout(uint8_t timeout)
Definition: usart.cpp:321
USART::flushOutputBuffer
void flushOutputBuffer(void)
Definition: usart.cpp:53
TimeoutException
Definition: timeoutexception.h:8
USART::writeInt
void writeInt(uint16_t d)
Definition: usart.cpp:81