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1 | 58d82c77 | Tom Mullins | /*
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2 | HardwareSerial.cpp - Hardware serial library for Wiring
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3 | Copyright (c) 2006 Nicholas Zambetti. All right reserved.
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4 | |||
5 | This library is free software; you can redistribute it and/or
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6 | modify it under the terms of the GNU Lesser General Public
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7 | License as published by the Free Software Foundation; either
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8 | version 2.1 of the License, or (at your option) any later version.
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9 | |||
10 | This library is distributed in the hope that it will be useful,
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11 | but WITHOUT ANY WARRANTY; without even the implied warranty of
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12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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13 | Lesser General Public License for more details.
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14 | |||
15 | You should have received a copy of the GNU Lesser General Public
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16 | License along with this library; if not, write to the Free Software
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17 | Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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18 |
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19 | Modified 23 November 2006 by David A. Mellis
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20 | Modified 28 September 2010 by Mark Sproul
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21 | */
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22 | |||
23 | #include <stdlib.h> |
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24 | #include <stdio.h> |
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25 | #include <string.h> |
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26 | #include <inttypes.h> |
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27 | #include "Arduino.h" |
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28 | #include "wiring_private.h" |
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29 | |||
30 | // this next line disables the entire HardwareSerial.cpp,
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31 | // this is so I can support Attiny series and any other chip without a uart
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32 | #if defined(UBRRH) || defined(UBRR0H) || defined(UBRR1H) || defined(UBRR2H) || defined(UBRR3H)
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33 | |||
34 | #include "HardwareSerial.h" |
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35 | |||
36 | // Define constants and variables for buffering incoming serial data. We're
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37 | // using a ring buffer (I think), in which head is the index of the location
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38 | // to which to write the next incoming character and tail is the index of the
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39 | // location from which to read.
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40 | #if (RAMEND < 1000) |
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41 | #define SERIAL_BUFFER_SIZE 16 |
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42 | #else
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43 | #define SERIAL_BUFFER_SIZE 64 |
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44 | #endif
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45 | |||
46 | struct ring_buffer
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47 | { |
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48 | unsigned char buffer[SERIAL_BUFFER_SIZE]; |
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49 | volatile int head; |
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50 | volatile int tail; |
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51 | }; |
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52 | |||
53 | #if defined(USBCON)
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54 | ring_buffer rx_buffer = { { 0 }, 0, 0}; |
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55 | ring_buffer tx_buffer = { { 0 }, 0, 0}; |
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56 | #endif
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57 | #if defined(UBRRH) || defined(UBRR0H)
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58 | ring_buffer rx_buffer = { { 0 }, 0, 0 }; |
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59 | ring_buffer tx_buffer = { { 0 }, 0, 0 }; |
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60 | #endif
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61 | #if defined(UBRR1H)
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62 | ring_buffer rx_buffer1 = { { 0 }, 0, 0 }; |
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63 | ring_buffer tx_buffer1 = { { 0 }, 0, 0 }; |
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64 | #endif
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65 | #if defined(UBRR2H)
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66 | ring_buffer rx_buffer2 = { { 0 }, 0, 0 }; |
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67 | ring_buffer tx_buffer2 = { { 0 }, 0, 0 }; |
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68 | #endif
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69 | #if defined(UBRR3H)
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70 | ring_buffer rx_buffer3 = { { 0 }, 0, 0 }; |
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71 | ring_buffer tx_buffer3 = { { 0 }, 0, 0 }; |
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72 | #endif
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73 | |||
74 | inline void store_char(unsigned char c, ring_buffer *buffer) |
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75 | { |
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76 | int i = (unsigned int)(buffer->head + 1) % SERIAL_BUFFER_SIZE; |
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77 | |||
78 | // if we should be storing the received character into the location
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79 | // just before the tail (meaning that the head would advance to the
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80 | // current location of the tail), we're about to overflow the buffer
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81 | // and so we don't write the character or advance the head.
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82 | if (i != buffer->tail) {
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83 | buffer->buffer[buffer->head] = c; |
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84 | buffer->head = i; |
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85 | } |
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86 | } |
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87 | |||
88 | #if !defined(USART0_RX_vect) && defined(USART1_RX_vect)
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89 | // do nothing - on the 32u4 the first USART is USART1
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90 | #else
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91 | #if !defined(USART_RX_vect) && !defined(SIG_USART0_RECV) && \
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92 | !defined(SIG_UART0_RECV) && !defined(USART0_RX_vect) && \ |
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93 | !defined(SIG_UART_RECV) |
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94 | #error "Don't know what the Data Received vector is called for the first UART" |
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95 | #else
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96 | void serialEvent() __attribute__((weak));
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97 | void serialEvent() {}
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98 | #define serialEvent_implemented
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99 | #if defined(USART_RX_vect)
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100 | SIGNAL(USART_RX_vect) |
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101 | #elif defined(SIG_USART0_RECV)
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102 | SIGNAL(SIG_USART0_RECV) |
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103 | #elif defined(SIG_UART0_RECV)
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104 | SIGNAL(SIG_UART0_RECV) |
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105 | #elif defined(USART0_RX_vect)
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106 | SIGNAL(USART0_RX_vect) |
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107 | #elif defined(SIG_UART_RECV)
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108 | SIGNAL(SIG_UART_RECV) |
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109 | #endif
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110 | { |
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111 | #if defined(UDR0)
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112 | unsigned char c = UDR0; |
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113 | #elif defined(UDR)
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114 | unsigned char c = UDR; |
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115 | #else
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116 | #error UDR not defined |
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117 | #endif
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118 | store_char(c, &rx_buffer); |
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119 | } |
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120 | #endif
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121 | #endif
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122 | |||
123 | #if defined(USART1_RX_vect)
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124 | void serialEvent1() __attribute__((weak));
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125 | void serialEvent1() {}
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126 | #define serialEvent1_implemented
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127 | SIGNAL(USART1_RX_vect) |
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128 | { |
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129 | unsigned char c = UDR1; |
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130 | store_char(c, &rx_buffer1); |
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131 | } |
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132 | #elif defined(SIG_USART1_RECV)
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133 | #error SIG_USART1_RECV
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134 | #endif
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135 | |||
136 | #if defined(USART2_RX_vect) && defined(UDR2)
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137 | void serialEvent2() __attribute__((weak));
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138 | void serialEvent2() {}
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139 | #define serialEvent2_implemented
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140 | SIGNAL(USART2_RX_vect) |
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141 | { |
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142 | unsigned char c = UDR2; |
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143 | store_char(c, &rx_buffer2); |
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144 | } |
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145 | #elif defined(SIG_USART2_RECV)
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146 | #error SIG_USART2_RECV
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147 | #endif
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148 | |||
149 | #if defined(USART3_RX_vect) && defined(UDR3)
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150 | void serialEvent3() __attribute__((weak));
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151 | void serialEvent3() {}
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152 | #define serialEvent3_implemented
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153 | SIGNAL(USART3_RX_vect) |
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154 | { |
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155 | unsigned char c = UDR3; |
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156 | store_char(c, &rx_buffer3); |
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157 | } |
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158 | #elif defined(SIG_USART3_RECV)
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159 | #error SIG_USART3_RECV
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160 | #endif
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161 | |||
162 | void serialEventRun(void) |
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163 | { |
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164 | #ifdef serialEvent_implemented
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165 | if (Serial.available()) serialEvent();
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166 | #endif
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167 | #ifdef serialEvent1_implemented
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168 | if (Serial1.available()) serialEvent1();
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169 | #endif
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170 | #ifdef serialEvent2_implemented
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171 | if (Serial2.available()) serialEvent2();
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172 | #endif
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173 | #ifdef serialEvent3_implemented
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174 | if (Serial3.available()) serialEvent3();
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175 | #endif
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176 | } |
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177 | |||
178 | |||
179 | #if !defined(USART0_UDRE_vect) && defined(USART1_UDRE_vect)
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180 | // do nothing - on the 32u4 the first USART is USART1
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181 | #else
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182 | #if !defined(UART0_UDRE_vect) && !defined(UART_UDRE_vect) && !defined(USART0_UDRE_vect) && !defined(USART_UDRE_vect)
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183 | #error "Don't know what the Data Register Empty vector is called for the first UART" |
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184 | #else
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185 | #if defined(UART0_UDRE_vect)
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186 | ISR(UART0_UDRE_vect) |
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187 | #elif defined(UART_UDRE_vect)
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188 | ISR(UART_UDRE_vect) |
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189 | #elif defined(USART0_UDRE_vect)
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190 | ISR(USART0_UDRE_vect) |
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191 | #elif defined(USART_UDRE_vect)
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192 | ISR(USART_UDRE_vect) |
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193 | #endif
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194 | { |
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195 | if (tx_buffer.head == tx_buffer.tail) {
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196 | // Buffer empty, so disable interrupts
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197 | #if defined(UCSR0B)
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198 | cbi(UCSR0B, UDRIE0); |
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199 | #else
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200 | cbi(UCSRB, UDRIE); |
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201 | #endif
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202 | } |
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203 | else {
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204 | // There is more data in the output buffer. Send the next byte
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205 | unsigned char c = tx_buffer.buffer[tx_buffer.tail]; |
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206 | tx_buffer.tail = (tx_buffer.tail + 1) % SERIAL_BUFFER_SIZE;
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207 | |||
208 | #if defined(UDR0)
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209 | UDR0 = c; |
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210 | #elif defined(UDR)
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211 | UDR = c; |
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212 | #else
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213 | #error UDR not defined |
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214 | #endif
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215 | } |
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216 | } |
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217 | #endif
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218 | #endif
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219 | |||
220 | #ifdef USART1_UDRE_vect
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221 | ISR(USART1_UDRE_vect) |
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222 | { |
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223 | if (tx_buffer1.head == tx_buffer1.tail) {
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224 | // Buffer empty, so disable interrupts
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225 | cbi(UCSR1B, UDRIE1); |
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226 | } |
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227 | else {
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228 | // There is more data in the output buffer. Send the next byte
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229 | unsigned char c = tx_buffer1.buffer[tx_buffer1.tail]; |
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230 | tx_buffer1.tail = (tx_buffer1.tail + 1) % SERIAL_BUFFER_SIZE;
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231 | |||
232 | UDR1 = c; |
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233 | } |
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234 | } |
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235 | #endif
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236 | |||
237 | #ifdef USART2_UDRE_vect
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238 | ISR(USART2_UDRE_vect) |
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239 | { |
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240 | if (tx_buffer2.head == tx_buffer2.tail) {
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241 | // Buffer empty, so disable interrupts
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242 | cbi(UCSR2B, UDRIE2); |
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243 | } |
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244 | else {
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245 | // There is more data in the output buffer. Send the next byte
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246 | unsigned char c = tx_buffer2.buffer[tx_buffer2.tail]; |
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247 | tx_buffer2.tail = (tx_buffer2.tail + 1) % SERIAL_BUFFER_SIZE;
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248 | |||
249 | UDR2 = c; |
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250 | } |
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251 | } |
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252 | #endif
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253 | |||
254 | #ifdef USART3_UDRE_vect
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255 | ISR(USART3_UDRE_vect) |
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256 | { |
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257 | if (tx_buffer3.head == tx_buffer3.tail) {
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258 | // Buffer empty, so disable interrupts
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259 | cbi(UCSR3B, UDRIE3); |
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260 | } |
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261 | else {
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262 | // There is more data in the output buffer. Send the next byte
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263 | unsigned char c = tx_buffer3.buffer[tx_buffer3.tail]; |
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264 | tx_buffer3.tail = (tx_buffer3.tail + 1) % SERIAL_BUFFER_SIZE;
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265 | |||
266 | UDR3 = c; |
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267 | } |
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268 | } |
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269 | #endif
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270 | |||
271 | |||
272 | // Constructors ////////////////////////////////////////////////////////////////
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273 | |||
274 | HardwareSerial::HardwareSerial(ring_buffer *rx_buffer, ring_buffer *tx_buffer, |
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275 | volatile uint8_t *ubrrh, volatile uint8_t *ubrrl, |
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276 | volatile uint8_t *ucsra, volatile uint8_t *ucsrb, |
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277 | volatile uint8_t *udr,
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278 | uint8_t rxen, uint8_t txen, uint8_t rxcie, uint8_t udrie, uint8_t u2x) |
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279 | { |
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280 | _rx_buffer = rx_buffer; |
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281 | _tx_buffer = tx_buffer; |
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282 | _ubrrh = ubrrh; |
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283 | _ubrrl = ubrrl; |
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284 | _ucsra = ucsra; |
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285 | _ucsrb = ucsrb; |
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286 | _udr = udr; |
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287 | _rxen = rxen; |
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288 | _txen = txen; |
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289 | _rxcie = rxcie; |
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290 | _udrie = udrie; |
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291 | _u2x = u2x; |
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292 | } |
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293 | |||
294 | // Public Methods //////////////////////////////////////////////////////////////
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295 | |||
296 | void HardwareSerial::begin(unsigned long baud) |
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297 | { |
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298 | uint16_t baud_setting; |
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299 | bool use_u2x = true; |
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300 | |||
301 | #if F_CPU == 16000000UL |
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302 | // hardcoded exception for compatibility with the bootloader shipped
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303 | // with the Duemilanove and previous boards and the firmware on the 8U2
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304 | // on the Uno and Mega 2560.
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305 | if (baud == 57600) { |
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306 | use_u2x = false;
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307 | } |
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308 | #endif
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309 | |||
310 | try_again:
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311 | |||
312 | if (use_u2x) {
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313 | *_ucsra = 1 << _u2x;
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314 | baud_setting = (F_CPU / 4 / baud - 1) / 2; |
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315 | } else {
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316 | *_ucsra = 0;
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317 | baud_setting = (F_CPU / 8 / baud - 1) / 2; |
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318 | } |
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319 | |||
320 | if ((baud_setting > 4095) && use_u2x) |
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321 | { |
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322 | use_u2x = false;
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323 | goto try_again;
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324 | } |
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325 | |||
326 | // assign the baud_setting, a.k.a. ubbr (USART Baud Rate Register)
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327 | *_ubrrh = baud_setting >> 8;
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328 | *_ubrrl = baud_setting; |
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329 | |||
330 | sbi(*_ucsrb, _rxen); |
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331 | sbi(*_ucsrb, _txen); |
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332 | sbi(*_ucsrb, _rxcie); |
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333 | cbi(*_ucsrb, _udrie); |
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334 | } |
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335 | |||
336 | void HardwareSerial::end()
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337 | { |
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338 | // wait for transmission of outgoing data
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339 | while (_tx_buffer->head != _tx_buffer->tail)
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340 | ; |
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341 | |||
342 | cbi(*_ucsrb, _rxen); |
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343 | cbi(*_ucsrb, _txen); |
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344 | cbi(*_ucsrb, _rxcie); |
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345 | cbi(*_ucsrb, _udrie); |
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346 | |||
347 | // clear any received data
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348 | _rx_buffer->head = _rx_buffer->tail; |
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349 | } |
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350 | |||
351 | int HardwareSerial::available(void) |
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352 | { |
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353 | return (unsigned int)(SERIAL_BUFFER_SIZE + _rx_buffer->head - _rx_buffer->tail) % SERIAL_BUFFER_SIZE; |
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354 | } |
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355 | |||
356 | int HardwareSerial::peek(void) |
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357 | { |
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358 | if (_rx_buffer->head == _rx_buffer->tail) {
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359 | return -1; |
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360 | } else {
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361 | return _rx_buffer->buffer[_rx_buffer->tail];
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362 | } |
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363 | } |
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364 | |||
365 | int HardwareSerial::read(void) |
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366 | { |
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367 | // if the head isn't ahead of the tail, we don't have any characters
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368 | if (_rx_buffer->head == _rx_buffer->tail) {
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369 | return -1; |
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370 | } else {
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371 | unsigned char c = _rx_buffer->buffer[_rx_buffer->tail]; |
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372 | _rx_buffer->tail = (unsigned int)(_rx_buffer->tail + 1) % SERIAL_BUFFER_SIZE; |
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373 | return c;
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374 | } |
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375 | } |
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376 | |||
377 | void HardwareSerial::flush()
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378 | { |
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379 | while (_tx_buffer->head != _tx_buffer->tail)
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380 | ; |
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381 | } |
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382 | |||
383 | size_t HardwareSerial::write(uint8_t c) |
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384 | { |
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385 | int i = (_tx_buffer->head + 1) % SERIAL_BUFFER_SIZE; |
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386 | |||
387 | // If the output buffer is full, there's nothing for it other than to
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388 | // wait for the interrupt handler to empty it a bit
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389 | // ???: return 0 here instead?
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390 | while (i == _tx_buffer->tail)
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391 | ; |
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392 | |||
393 | _tx_buffer->buffer[_tx_buffer->head] = c; |
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394 | _tx_buffer->head = i; |
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395 | |||
396 | sbi(*_ucsrb, _udrie); |
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397 | |||
398 | return 1; |
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399 | } |
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400 | |||
401 | // Preinstantiate Objects //////////////////////////////////////////////////////
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402 | |||
403 | #if defined(UBRRH) && defined(UBRRL)
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404 | HardwareSerial Serial(&rx_buffer, &tx_buffer, &UBRRH, &UBRRL, &UCSRA, &UCSRB, &UDR, RXEN, TXEN, RXCIE, UDRIE, U2X); |
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405 | #elif defined(UBRR0H) && defined(UBRR0L)
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406 | HardwareSerial Serial(&rx_buffer, &tx_buffer, &UBRR0H, &UBRR0L, &UCSR0A, &UCSR0B, &UDR0, RXEN0, TXEN0, RXCIE0, UDRIE0, U2X0); |
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407 | #elif defined(USBCON)
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408 | // do nothing - Serial object and buffers are initialized in CDC code
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409 | #else
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410 | #error no serial port defined (port 0) |
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411 | #endif
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412 | |||
413 | #if defined(UBRR1H)
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414 | HardwareSerial Serial1(&rx_buffer1, &tx_buffer1, &UBRR1H, &UBRR1L, &UCSR1A, &UCSR1B, &UDR1, RXEN1, TXEN1, RXCIE1, UDRIE1, U2X1); |
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415 | #endif
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416 | #if defined(UBRR2H)
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417 | HardwareSerial Serial2(&rx_buffer2, &tx_buffer2, &UBRR2H, &UBRR2L, &UCSR2A, &UCSR2B, &UDR2, RXEN2, TXEN2, RXCIE2, UDRIE2, U2X2); |
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418 | #endif
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419 | #if defined(UBRR3H)
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420 | HardwareSerial Serial3(&rx_buffer3, &tx_buffer3, &UBRR3H, &UBRR3L, &UCSR3A, &UCSR3B, &UDR3, RXEN3, TXEN3, RXCIE3, UDRIE3, U2X3); |
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421 | #endif
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422 | |||
423 | #endif // whole file |