diff --git a/stk500v2/main.cpp b/stk500v2/main.cpp index 4513bf1..405ce4a 100644 --- a/stk500v2/main.cpp +++ b/stk500v2/main.cpp @@ -2,6 +2,8 @@ #include "uart/uart.hpp" +#include + #include #include #include @@ -9,7 +11,10 @@ #include "command.hpp" -using uart_interface = uart::Hardware0, uart::Driven::BLOCKING>; +static constexpr auto TIMEOUT = 5000; +static constexpr auto BAUD_RATE = 115200; + +using uart_interface = uart::Hardware0, uart::Driven::BLOCKING>; uart::Uart serial; struct Message { @@ -21,11 +26,26 @@ struct Message { uint8_t checksum; }; -static inline bool receiveByte(uint8_t &data, uint32_t timeout = 100000) +static inline bool receiveByte(uint8_t &data, uint16_t &timeout) { - for (uint32_t i = 0; i < timeout; ++i) { - if (serial.rxByte(data)) + constexpr auto MICROSECOND = 1000.0 * 1000; + constexpr auto SYMBOL_SIZE = 9; + constexpr auto BYTE_DELAY_US = (SYMBOL_SIZE * MICROSECOND) / BAUD_RATE; + constexpr auto NUM_MS_DELAY_STEPS = static_cast(round(1000 / BYTE_DELAY_US)); + uint16_t msDelay = NUM_MS_DELAY_STEPS; + + while (timeout) { + if (serial.rxByte(data)) { + timeout = TIMEOUT; return true; + } + + _delay_us(BYTE_DELAY_US); + + if (--msDelay == 0) { + msDelay = NUM_MS_DELAY_STEPS; + --timeout; + } } return false; @@ -42,23 +62,23 @@ static inline uint8_t calcChecksum(const Message &msg) return checksum; } -static inline bool receiveMessage(Message &msg) +static inline bool receiveMessage(Message &msg, uint16_t &timeout) { - if (!receiveByte(msg.start) || msg.start != MESSAGE_START) + if (!receiveByte(msg.start, timeout) || msg.start != MESSAGE_START) return false; - if (!receiveByte(msg.number)) + if (!receiveByte(msg.number, timeout)) return false; - if (!receiveByte(*(reinterpret_cast(&msg.size) + 1))) + if (!receiveByte(*(reinterpret_cast(&msg.size) + 1), timeout)) return false; - if (!receiveByte(*reinterpret_cast(&msg.size)) || msg.size > sizeof(msg.body)) + if (!receiveByte(*reinterpret_cast(&msg.size), timeout) || msg.size > sizeof(msg.body)) return false; - if (!receiveByte(msg.token) || msg.token != TOKEN) + if (!receiveByte(msg.token, timeout) || msg.token != TOKEN) return false; for (uint16_t i = 0; i < msg.size; ++i) { - if (!receiveByte(msg.body[i])) + if (!receiveByte(msg.body[i], timeout)) return false; } - if (!receiveByte(msg.checksum) || msg.checksum != calcChecksum(msg)) + if (!receiveByte(msg.checksum, timeout) || msg.checksum != calcChecksum(msg)) return false; return true; @@ -551,11 +571,15 @@ int main() Message msg; uint32_t addr = 0x0000; ChipEraseState chipEraseFlag = ChipEraseState::NONE; + uint16_t timeout = TIMEOUT; while (true) { - if (receiveMessage(msg)) { + if (receiveMessage(msg, timeout)) { handleMessage(msg, addr, chipEraseFlag); } + + if (timeout == 0) + timeout = TIMEOUT; } return 0;