1 | #include <avr/io.h>
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2 | #include <util/delay.h>
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3 | #include <compat/twi.h>
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4 | #include <avr/interrupt.h>
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5 | #include "l74hc4051.h"
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6 | #include "adc.h"
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7 |
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8 | #define I2C_ADDR 0x4E
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9 |
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10 | #deinfe OP_RESET 0x00
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11 | #define OP_PROBE 0x01
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12 | #define OP_SINGLE 0x02
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13 |
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14 | #define IODIR 0x00
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15 | #define GPIO 0x09
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16 | #define OLAT 0x0A
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17 | unsigned char regaddr; // Store the MCP23008 Requested Register Address
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18 | unsigned char regdata; // Store the MCP23008 Register Address Data
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19 | unsigned char index;
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20 |
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21 | uint16_t current_values[40] = {0};
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22 | uint16_t old_values[40] = {0};
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23 |
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24 | void i2c_slave_action(unsigned char rw_status)
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25 | {
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26 | // rw_status: 0-Read, 1-Write
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27 | switch(regaddr) {
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28 |
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29 | case OP_RESET:
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30 | if(rw_status)++
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31 | {
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32 | index = 0;
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33 | }
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34 | else
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35 | {
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36 | index = 0;
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37 | regdata = 0xFF;
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38 | }
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39 | break;
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40 |
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41 |
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42 | case OP_PROBE:
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43 | if (rw_status) {
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44 | } else {
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45 | if(index < 80)
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46 | {
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47 | regdata=current_values[index++];
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48 | }
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49 | else
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50 | {
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51 | index = 0;
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52 | regdata=0x00;
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53 | }
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54 | }
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55 | break;
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56 | }
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57 | }
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58 | ISR(TWI_vect)
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59 | {
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60 | static unsigned char i2c_state;
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61 | unsigned char twi_status;
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62 | // Disable Global Interrupt
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63 | cli();
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64 | // Get TWI Status Register, mask the prescaler bits (TWPS1,TWPS0)
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65 | twi_status=TWSR & 0xF8;
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66 |
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67 | switch(twi_status) {
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68 | case TW_SR_SLA_ACK: // 0x60: SLA+W received, ACK returned
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69 | i2c_state=0; // Start I2C State for Register Address required
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70 |
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71 | TWCR |= (1<<TWINT); // Clear TWINT Flag
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72 | break;
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73 | case TW_SR_DATA_ACK: // 0x80: data received, ACK returned
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74 | if (i2c_state == 0) {
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75 | regaddr = TWDR; // Save data to the register address
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76 | i2c_state = 1;
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77 | } else {
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78 | regdata = TWDR; // Save to the register data
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79 | i2c_state = 2;
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80 | }
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81 |
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82 | TWCR |= (1<<TWINT); // Clear TWINT Flag
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83 | break;
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84 | case TW_SR_STOP: // 0xA0: stop or repeated start condition received while selected
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85 | if (i2c_state == 2) {
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86 | i2c_slave_action(1); // Call Write I2C Action (rw_status = 1)
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87 | i2c_state = 0; // Reset I2C State
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88 | }
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89 |
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90 | TWCR |= (1<<TWINT); // Clear TWINT Flag
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91 | break;
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92 |
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93 | case TW_ST_SLA_ACK: // 0xA8: SLA+R received, ACK returned
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94 | case TW_ST_DATA_ACK: // 0xB8: data transmitted, ACK received
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95 | if (i2c_state == 1) {
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96 | i2c_slave_action(0); // Call Read I2C Action (rw_status = 0)
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97 | TWDR = regdata; // Store data in TWDR register
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98 | i2c_state = 0; // Reset I2C State
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99 | }
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100 |
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101 | TWCR |= (1<<TWINT); // Clear TWINT Flag
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102 | break;
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103 | case TW_ST_DATA_NACK: // 0xC0: data transmitted, NACK received
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104 | case TW_ST_LAST_DATA: // 0xC8: last data byte transmitted, ACK received
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105 | case TW_BUS_ERROR: // 0x00: illegal start or stop condition
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106 | default:
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107 | TWCR |= (1<<TWINT); // Clear TWINT Flag
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108 | i2c_state = 0; // Back to the Begining State
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109 | }
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110 | // Enable Global Interrupt
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111 | sei();
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112 | }
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113 | int main(void)
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114 | {
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115 | DDRB = 0xFE; // Set PORTB: PB0=Input, Others as Output
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116 | PORTB = 0x00;
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117 | DDRD = 0xFF; // Set PORTD to Output
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118 | PORTD = 0x00; // Set All PORTD to Low
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119 |
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120 |
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121 | // XXX
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122 | l74hc4051_init();
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123 | adc_setchannel(1);
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124 | adc_init();
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125 |
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126 | // Initial I2C Slave
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127 | TWAR = I2C_ADDR & 0xFE; // Set I2C Address, Ignore I2C General Address 0x00
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128 | TWDR = 0x00; // Default Initial Value
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129 | // Start Slave Listening: Clear TWINT Flag, Enable ACK, Enable TWI, TWI Interrupt Enable
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130 | TWCR = (1<<TWINT) | (1<<TWEA) | (1<<TWEN) | (1<<TWIE);
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131 | // Enable Global Interrupt
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132 | sei();
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133 |
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134 | // Initial Variable Used
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135 | regaddr=0;
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136 | regdata=0;
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137 |
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138 | for(;;) {
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139 | uint8_t i,j = 0;
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140 | for(j=0; j < 5; j++)
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141 | {
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142 | for(i=0; i<L74HC4051_MAXCH; i++) {
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143 | l74hc4051_setchannel(i);
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144 | current_values[i*j] = adc_read(j);
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145 | }
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146 | _delay_us(100);
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147 | }
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148 |
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149 | }
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150 | return 0;
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151 | }
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