1 | /*
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2 | PubNub sample JSON-parsing client with WiFi support
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3 |
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4 | This combines two sketches: the PubNubJson example of PubNub library
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5 | and the WifiWebClientRepeating example of the WiFi library.
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6 |
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7 | This sample client will properly parse JSON-encoded PubNub subscription
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8 | replies using the aJson library. It will send a simple message, then
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9 | properly parsing and inspecting a subscription message received back.
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10 |
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11 | This is achieved by integration with the aJson library. You will need
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12 | a version featuring Wiring Stream integration, that can be found
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13 | at http://github.com/pasky/aJson as of 2013-05-30.
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14 |
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15 | Circuit:
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16 | * Wifi shield attached to pins 10, 11, 12, 13
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17 | * (Optional) Analog sensors attached to analog pin.
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18 | * (Optional) LEDs to be dimmed attached to PWM pins 8 and 9.
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19 |
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20 |
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21 | Please refer to the PubNubJson example description for some important
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22 | notes, especially regarding memory saving on Arduino Uno/Duemilanove.
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23 | You can also save some RAM by not using WiFi password protection.
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24 |
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25 |
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26 | created 30 May 2013
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27 | by Petr Baudis
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28 |
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29 | https://github.com/pubnub/pubnub-api/tree/master/arduino
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30 | This code is in the public domain.
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31 | */
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32 |
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33 | #include <SPI.h>
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34 | #include <WiFi.h>
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35 | #include <PubNub.h>
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36 | #include <aJSON.h>
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37 |
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38 | static char ssid[] = "yourNetwork"; // your network SSID (name)
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39 | static char pass[] = "secretPassword"; // your network password
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40 | static int keyIndex = 0; // your network key Index number (needed only for WEP)
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41 |
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42 | const static char pubkey[] = "demo";
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43 | const static char subkey[] = "demo";
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44 | const static char channel[] = "hello_world";
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45 |
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46 | void setup()
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47 | {
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48 | Serial.begin(9600);
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49 | Serial.println("Serial set up");
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50 |
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51 | if (WiFi.status() == WL_NO_SHIELD) {
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52 | Serial.println("WiFi shield not present");
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53 | while(true); // stop
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54 | }
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55 |
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56 | int status;
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57 | // attempt to connect to Wifi network:
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58 | do {
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59 | Serial.print("WiFi connecting to SSID: ");
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60 | Serial.println(ssid);
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61 |
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62 | // Connect to the network. Uncomment whichever line is right for you:
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63 | //status = WiFi.begin(ssid); // open network
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64 | //status = WiFi.begin(ssid, keyIndex, key); // WEP network
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65 | status = WiFi.begin(ssid, pass); // WPA / WPA2 Personal network
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66 | } while (status != WL_CONNECTED);
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67 | Serial.println("WiFi set up");
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68 |
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69 | PubNub.begin(pubkey, subkey);
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70 | Serial.println("PubNub set up");
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71 | }
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72 |
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73 | aJsonObject *createMessage()
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74 | {
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75 | aJsonObject *msg = aJson.createObject();
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76 |
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77 | aJsonObject *sender = aJson.createObject();
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78 | aJson.addStringToObject(sender, "name", "Arduino");
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79 | aJson.addItemToObject(msg, "sender", sender);
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80 |
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81 | int analogValues[6];
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82 | for (int i = 0; i < 6; i++) {
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83 | analogValues[i] = analogRead(i);
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84 | }
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85 | aJsonObject *analog = aJson.createIntArray(analogValues, 6);
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86 | aJson.addItemToObject(msg, "analog", analog);
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87 | return msg;
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88 | }
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89 |
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90 | /* Process message like: { "pwm": { "8": 0, "9": 128 } } */
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91 | void processPwmInfo(aJsonObject *item)
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92 | {
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93 | aJsonObject *pwm = aJson.getObjectItem(item, "pwm");
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94 | if (!pwm) {
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95 | Serial.println("no pwm data");
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96 | return;
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97 | }
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98 |
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99 | const static int pins[] = { 8, 9 };
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100 | const static int pins_n = 2;
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101 | for (int i = 0; i < pins_n; i++) {
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102 | char pinstr[3];
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103 | snprintf(pinstr, sizeof(pinstr), "%d", pins[i]);
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104 |
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105 | aJsonObject *pwmval = aJson.getObjectItem(pwm, pinstr);
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106 | if (!pwmval) continue; /* Value not provided, ok. */
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107 | if (pwmval->type != aJson_Int) {
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108 | Serial.print(" invalid data type ");
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109 | Serial.print(pwmval->type, DEC);
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110 | Serial.print(" for pin ");
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111 | Serial.println(pins[i], DEC);
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112 | continue;
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113 | }
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114 |
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115 | Serial.print(" setting pin ");
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116 | Serial.print(pins[i], DEC);
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117 | Serial.print(" to value ");
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118 | Serial.println(pwmval->valueint, DEC);
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119 | analogWrite(pins[i], pwmval->valueint);
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120 | }
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121 | }
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122 |
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123 | void dumpMessage(Stream &s, aJsonObject *msg)
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124 | {
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125 | int msg_count = aJson.getArraySize(msg);
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126 | for (int i = 0; i < msg_count; i++) {
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127 | aJsonObject *item, *sender, *analog, *value;
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128 | s.print("Msg #");
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129 | s.println(i, DEC);
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130 |
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131 | item = aJson.getArrayItem(msg, i);
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132 | if (!item) { s.println("item not acquired"); delay(1000); return; }
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133 |
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134 | processPwmInfo(item);
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135 |
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136 | /* Below, we parse and dump messages from fellow Arduinos. */
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137 |
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138 | sender = aJson.getObjectItem(item, "sender");
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139 | if (!sender) { s.println("sender not acquired"); delay(1000); return; }
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140 |
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141 | s.print(" A2: ");
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142 | analog = aJson.getObjectItem(item, "analog");
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143 | if (!analog) { s.println("analog not acquired"); delay(1000); return; }
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144 | value = aJson.getArrayItem(analog, 2);
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145 | if (!value) { s.println("analog[2] not acquired"); delay(1000); return; }
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146 | s.print(value->valueint, DEC);
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147 |
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148 | s.println();
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149 | }
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150 | }
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151 |
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152 | void loop()
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153 | {
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154 | // Intriguingly, the WiFi library doesn't seem to have a call
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155 | // equivalent to Ethernet.maintain();
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156 | //WiFi.maintain();
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157 |
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158 | WiFiClient *client;
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159 |
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160 | /* Publish */
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161 |
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162 | Serial.print("publishing a message: ");
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163 | aJsonObject *msg = createMessage();
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164 | char *msgStr = aJson.print(msg);
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165 | aJson.deleteItem(msg);
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166 |
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167 | // msgStr is returned in a buffer that can be potentially
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168 | // needlessly large; this call will "tighten" it
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169 | msgStr = (char *) realloc(msgStr, strlen(msgStr) + 1);
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170 |
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171 | Serial.println(msgStr);
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172 | client = PubNub.publish(channel, msgStr);
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173 | free(msgStr);
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174 | if (!client) {
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175 | Serial.println("publishing error");
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176 | delay(1000);
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177 | return;
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178 | }
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179 | client->stop();
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180 |
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181 | /* Subscribe and load reply */
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182 |
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183 | Serial.println("waiting for a message (subscribe)");
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184 | client = PubNub.subscribe(channel);
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185 | if (!client) {
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186 | Serial.println("subscription error");
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187 | delay(1000);
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188 | return;
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189 | }
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190 |
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191 | /* Parse */
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192 |
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193 | aJsonClientStream stream(client);
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194 | msg = aJson.parse(&stream);
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195 | client->stop();
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196 | if (!msg) { Serial.println("parse error"); delay(1000); return; }
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197 | dumpMessage(Serial, msg);
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198 | aJson.deleteItem(msg);
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199 |
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200 | delay(10000);
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201 | }
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