Flush UART RX buffer before receiving answer from EDU (#482)

Fixes #478 

At least, I hope if finally fixes that issue. A quick test with and
without redirecting RF over UCI was successful.

Author: PatrickKa

Sts1CobcSw/Edu/Edu.cpp

@@ -111,7 +111,6 @@ template<>
 
 template<typename T>
 [[nodiscard]] auto Retry(auto (*communicationFunction)()->Result<T>, int nTries) -> Result<T>;
-auto FlushUartReceiveBuffer() -> void;
 }
 
 
@@ -493,6 +492,7 @@ auto SendDataPacket(std::span<Byte const> data) -> Result<void>
         OUTCOME_TRY(Send(data));
         OUTCOME_TRY(Send(Span(checksum)));
 
+        hal::FlushReceiveBuffer(&uart);
         OUTCOME_TRY(auto answer, Receive<Byte>());
         switch(answer)
         {
@@ -628,7 +628,7 @@ auto Retry(auto (*communicationFunction)()->Result<T>, int nTries) -> Result<T>
             // No ACK is sent here. The caller is responsible for that.
             return result;
         }
-        FlushUartReceiveBuffer();
+        hal::FlushReceiveBuffer(&uart);
         OUTCOME_TRY(SendCommand(cepNack));
         iTries++;
         if(iTries >= nTries)
@@ -638,22 +638,5 @@ auto Retry(auto (*communicationFunction)()->Result<T>, int nTries) -> Result<T>
         }
     }
 }
-
-
-//! @brief Flush the EDU UART read buffer.
-//!
-//! This can be used to clear all buffer data after an error to request a resend.
-auto FlushUartReceiveBuffer() -> void
-{
-    auto garbageBuffer = std::array<Byte, 32>{};  // NOLINT(*magic-numbers)
-    while(true)
-    {
-        auto readFromResult = hal::ReadFrom(&uart, Span(&garbageBuffer), flushReceiveBufferTimeout);
-        if(readFromResult.has_error())
-        {
-            break;
-        }
-    }
-}
 }
 }

Sts1CobcSw/Hal/Uart.cpp

@@ -13,4 +13,14 @@ auto Initialize(RODOS::HAL_UART * uart, std::uint32_t baudRate) -> void
     // report. Also, the UART buffer size is capped at RODOS::UART_BUF_SIZE.
     uart->config(RODOS::UART_PARAMETER_ENABLE_DMA, RODOS::UART_BUF_SIZE);
 }
+
+
+auto FlushReceiveBuffer(RODOS::HAL_UART * uart) -> void
+{
+    while(uart->isDataReady())
+    {
+        std::uint8_t dummy;  // NOLINT(*init-variables)
+        uart->read(&dummy, 1);
+    }
+}
 }

Sts1CobcSw/Hal/Uart.hpp

@@ -30,6 +30,8 @@ auto ReadFrom(RODOS::HAL_UART * uart, std::span<T, extent> data) -> void;
 template<typename T, std::size_t extent>
 [[nodiscard]] auto ReadFrom(RODOS::HAL_UART * uart, std::span<T, extent> data, Duration timeout)
     -> Result<void>;
+
+auto FlushReceiveBuffer(RODOS::HAL_UART * uart) -> void;
 }