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1 /* Name: main.c |
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2 * Author: <insert your name here> |
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3 * Copyright: <insert your copyright message here> |
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4 * License: <insert your license reference here> |
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5 */ |
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6 |
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7 #include <stdio.h> |
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8 #include <string.h> |
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9 #include <avr/io.h> |
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10 #include <avr/interrupt.h> |
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11 #include <avr/sleep.h> |
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12 #include <util/crc16.h> |
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13 |
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14 // configuration params |
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15 // - measurement interval |
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16 // - transmit interval |
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17 // - bluetooth params |
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18 // - number of sensors (and range?) |
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19 |
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20 // 1 second. we have 1024 prescaler, 32768 crystal. |
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21 static const uint8_t CNT2_COMPARE = 32; |
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22 static const int SECONDS_WAKE = 60; |
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23 |
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24 static int uart_putchar(char c, FILE *stream); |
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25 static FILE mystdout = FDEV_SETUP_STREAM(uart_putchar, NULL, |
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26 _FDEV_SETUP_WRITE); |
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27 |
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28 static uint8_t n_measurements; |
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29 static uint8_t measurements[500]; |
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30 |
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31 static uint8_t need_measurement; |
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32 |
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33 static uint8_t readpos; |
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34 static char readbuf[30]; |
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35 |
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36 static uint8_t sec_count; |
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37 |
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38 static void |
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39 uart_init(unsigned int baud) |
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40 { |
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41 // baud rate |
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42 UBRRH = (unsigned char)(baud >> 8); |
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43 UBRRL = (unsigned char)baud; |
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44 UCSRB = (1<<RXEN)|(1<<TXEN); |
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45 //8N1 |
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46 UCSRC = (1<<URSEL)|(3<<UCSZ0); |
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47 } |
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48 |
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49 static int |
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50 uart_putchar(char c, FILE *stream) |
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51 { |
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52 // XXX should sleep in the loop for power. |
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53 loop_until_bit_is_set(UCSRA, UDRE); |
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54 UDR = c; |
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55 return 0; |
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56 } |
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57 |
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58 static void |
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59 cmd_fetch() |
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60 { |
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61 uint16_t crc = 0; |
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62 int i; |
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63 printf("%d measurements\n", n_measurements); |
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64 for (i = 0; i < n_measurements; i++) |
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65 { |
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66 printf("%3d : %d\n", i, measurements[i]); |
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67 crc = _crc_ccitt_update(crc, measurements[i]); |
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68 } |
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69 printf("CRC : %d\n", crc); |
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70 } |
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71 |
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72 static void |
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73 cmd_clear() |
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74 { |
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75 } |
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76 |
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77 static void |
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78 cmd_btoff() |
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79 { |
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80 } |
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81 |
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82 static void |
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83 read_handler() |
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84 { |
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85 if (strcmp(readbuf, "fetch") == 0) |
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86 { |
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87 cmd_fetch(); |
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88 } |
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89 else if (strcmp(readbuf, "clear") == 0) |
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90 { |
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91 cmd_clear(); |
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92 } |
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93 else if (strcmp(readbuf, "btoff") == 0) |
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94 { |
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95 cmd_btoff(); |
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96 } |
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97 else |
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98 { |
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99 printf("Bad command\n"); |
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100 } |
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101 } |
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102 |
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103 ISR(USART_RXC_vect) |
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104 { |
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105 char c = UDR; |
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106 if (c == '\n') |
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107 { |
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108 readbuf[readpos] = '\0'; |
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109 read_handler(); |
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110 readpos = 0; |
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111 } |
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112 else |
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113 { |
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114 readbuf[readpos] = c; |
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115 readpos++; |
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116 if (readpos >= sizeof(readbuf)) |
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117 { |
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118 readpos = 0; |
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119 } |
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120 } |
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121 } |
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122 |
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123 ISR(TIMER2_COMP_vect) |
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124 { |
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125 sec_count ++; |
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126 if (sec_count == SECONDS_WAKE) |
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127 { |
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128 sec_count = 0; |
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129 need_measurement = 1; |
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130 } |
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131 } |
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132 |
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133 static void |
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134 deep_sleep() |
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135 { |
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136 // p119 of manual |
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137 OCR2 = CNT2_COMPARE; |
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138 loop_until_bit_is_clear(ASSR, OCR2UB); |
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139 |
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140 set_sleep_mode(SLEEP_MODE_PWR_SAVE); |
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141 sleep_mode(); |
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142 } |
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143 |
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144 static void |
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145 do_measurement() |
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146 { |
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147 need_measurement = 0; |
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148 } |
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149 |
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150 int main(void) |
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151 { |
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152 uart_init(9600); |
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153 |
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154 fprintf(&mystdout, "hello %d\n", 12); |
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155 |
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156 // set up counter2. |
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157 // COM21 COM20 Set OC2 on Compare Match (p116) |
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158 // WGM21 Clear counter on compare |
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159 // CS22 CS21 CS20 clk/1024 |
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160 TCCR2 = _BV(COM21) | _BV(COM20) | _BV(WGM21) | _BV(CS22) | _BV(CS21) | _BV(CS20); |
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161 // set async mode |
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162 ASSR |= _BV(AS2); |
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163 |
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164 for(;;){ |
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165 /* insert your main loop code here */ |
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166 if (need_measurement) |
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167 { |
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168 do_measurement(); |
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169 } |
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170 } |
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171 return 0; /* never reached */ |
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172 } |
