Fix for arduino#295 to allow flexible bit rate either one of the 4 predefined rates or a custom rate

Author: fastbike

libraries/Arduino_CAN/src/CanUtil.cpp

@@ -28,7 +28,7 @@ namespace util
  **************************************************************************************/
 
 std::tuple<bool, uint32_t, uint32_t, uint32_t>
-  calc_can_bit_timing(CanBitRate const can_bitrate,
+  calc_can_bit_timing(uint32_t const can_bitrate,
                       uint32_t const can_clock_Hz,
                       uint32_t const tq_min,
                       uint32_t const tq_max,

libraries/Arduino_CAN/src/CanUtil.h

@@ -36,7 +36,7 @@ std::tuple<bool,     /* valid result found */
            uint32_t, /* baud_rate_prescaler */
            uint32_t, /* time_segment_1 */
            uint32_t> /* time_segment_2 */
-calc_can_bit_timing(CanBitRate const can_bitrate, uint32_t const can_clock_Hz, uint32_t const tq_min, uint32_t const tq_max,
+calc_can_bit_timing(uint32_t const can_bitrate, uint32_t const can_clock_Hz, uint32_t const tq_min, uint32_t const tq_max,
                     uint32_t const tseg1_min, uint32_t const tseg1_max, uint32_t const tseg2_min, uint32_t const tseg2_max);
 
 /**************************************************************************************

libraries/Arduino_CAN/src/R7FA4M1_CAN.cpp

@@ -137,6 +137,11 @@ R7FA4M1_CAN::R7FA4M1_CAN(int const can_tx_pin, int const can_rx_pin)
  **************************************************************************************/
 
 bool R7FA4M1_CAN::begin(CanBitRate const can_bitrate)
+{
+  return begin(static_cast<uint32_t>(can_bitrate)); 
+}
+
+bool R7FA4M1_CAN::begin(uint32_t const can_bitrate)
 {
   bool init_ok = true;
 
@@ -156,7 +161,7 @@ bool R7FA4M1_CAN::begin(CanBitRate const can_bitrate)
 
   /* Calculate the CAN bitrate based on the value of this functions parameter.
    */
-  static uint32_t const F_CAN_CLK_Hz = 24*1000*1000UL;
+  static uint32_t const F_CAN_CLK_Hz = 24*1000*1000UL;  
   static uint32_t const TQ_MIN     = 8;
   static uint32_t const TQ_MAX     = 25;
   static uint32_t const TSEG_1_MIN = 4;
@@ -167,7 +172,7 @@ bool R7FA4M1_CAN::begin(CanBitRate const can_bitrate)
   auto [is_valid_baudrate, baud_rate_prescaler, time_segment_1, time_segment_2] =
     util::calc_can_bit_timing(can_bitrate, F_CAN_CLK_Hz, TQ_MIN, TQ_MAX, TSEG_1_MIN, TSEG_1_MAX, TSEG_2_MIN, TSEG_2_MAX);
   init_ok &= is_valid_baudrate;
-
+  
   if (is_valid_baudrate) {
     _can_bit_timing_cfg.baud_rate_prescaler = baud_rate_prescaler;
     _can_bit_timing_cfg.time_segment_1 = time_segment_1;
@@ -182,6 +187,7 @@ bool R7FA4M1_CAN::begin(CanBitRate const can_bitrate)
   return init_ok;
 }
 
+////////////////////////
 void R7FA4M1_CAN::end()
 {
   R_CAN_Close(&_can_ctrl);

libraries/Arduino_CAN/src/R7FA4M1_CAN.h

@@ -52,6 +52,7 @@ class R7FA4M1_CAN final : public HardwareCAN
 
 
   bool begin(CanBitRate const can_bitrate) override;
+  bool begin(uint32_t const can_bitrate);
   void end() override;
 
   void setFilterMask_Standard(uint32_t const mask);