Shared Feeds (#52)

* add owner field to AdafruitIO_Feed

* remove spurious setup methods

* clean up some compiler warnings

* Fixing string comparison compile warnings

add strcmp to property assign.

* add example of feed writing

* adding feed writing example, bump lib version up

Author: brentru

examples/adafruitio_20_shared_feed_write/adafruitio_20_shared_feed_write.ino

@@ -0,0 +1,94 @@
+// Adafruit IO Shared Feeds Write Example
+// desc: Example of writing a button value to a shared feed.
+//
+// Tutorial Link: https://learn.adafruit.com/adafruit-io-basics-feeds/sharing-a-feed
+//
+// Adafruit invests time and resources providing this open source code.
+// Please support Adafruit and open source hardware by purchasing
+// products from Adafruit!
+//
+// Written by Brent Rubell for Adafruit Industries
+// Copyright (c) 2018 Adafruit Industries
+// Licensed under the MIT license.
+//
+// All text above must be included in any redistribution.
+
+/************************** Configuration ***********************************/
+
+// edit the config.h tab and enter your Adafruit IO credentials
+// and any additional configuration needed for WiFi, cellular,
+// or ethernet clients.
+#include "config.h"
+
+/************************ Example Starts Here *******************************/
+
+// digital pin 5
+#define BUTTON_PIN 5
+
+// the Adafruit IO username of whomever owns the feed
+#define FEED_OWNER "AIO_FEED_OWNER"
+
+// set up a shared feed between you and the FEED_OWNER 
+// make sure you have both read AND write access to this feed
+AdafruitIO_Feed *sharedFeed = io.feed("FEED-NAME", FEED_OWNER);
+
+// button state
+bool current = false;
+bool last = false;
+
+void setup() {
+
+  // set button pin as an input
+  pinMode(BUTTON_PIN, INPUT);
+
+  // start the serial connection
+  Serial.begin(115200);
+
+  // wait for serial monitor to open
+  while(! Serial);
+
+  // connect to io.adafruit.com
+  Serial.print("Connecting to Adafruit IO");
+  io.connect();
+
+  // wait for a connection
+  while(io.status() < AIO_CONNECTED) {
+    Serial.print(".");
+    delay(500);
+  }
+
+  // we are connected
+  Serial.println();
+  Serial.println(io.statusText());
+
+}
+
+void loop() {
+
+  // io.run(); is required for all sketches.
+  // it should always be present at the top of your loop
+  // function. it keeps the client connected to
+  // io.adafruit.com, and processes any incoming data.
+  io.run();
+
+  // grab the current state of the button.
+  // we have to flip the logic because we are
+  // using a pullup resistor.
+  if(digitalRead(BUTTON_PIN) == LOW)
+    current = true;
+  else
+    current = false;
+
+  // return if the value hasn't changed
+  if(current == last)
+    return;
+
+  // save the current state to the 'sharedFeed' feed on adafruit io
+  Serial.print("sending button -> ");
+  Serial.println(current);
+  sharedFeed->save(current);
+
+  // store last button state
+  last = current;
+
+}

examples/adafruitio_20_shared_feed_write/config.h

@@ -0,0 +1,44 @@
+/************************ Adafruit IO Config *******************************/
+
+// visit io.adafruit.com if you need to create an account,
+// or if you need your Adafruit IO key.
+#define IO_USERNAME    "your_username"
+#define IO_KEY         "your_key"
+
+/******************************* WIFI **************************************/
+
+// the AdafruitIO_WiFi client will work with the following boards:
+//   - HUZZAH ESP8266 Breakout -> https://www.adafruit.com/products/2471
+//   - Feather HUZZAH ESP8266 -> https://www.adafruit.com/products/2821
+//   - Feather HUZZAH ESP32 -> https://www.adafruit.com/product/3405
+//   - Feather M0 WiFi -> https://www.adafruit.com/products/3010
+//   - Feather WICED -> https://www.adafruit.com/products/3056
+
+#define WIFI_SSID       "your_ssid"
+#define WIFI_PASS       "your_pass"
+
+// comment out the following two lines if you are using fona or ethernet
+#include "AdafruitIO_WiFi.h"
+AdafruitIO_WiFi io(IO_USERNAME, IO_KEY, WIFI_SSID, WIFI_PASS);
+
+
+/******************************* FONA **************************************/
+
+// the AdafruitIO_FONA client will work with the following boards:
+//   - Feather 32u4 FONA -> https://www.adafruit.com/product/3027
+
+// uncomment the following two lines for 32u4 FONA,
+// and comment out the AdafruitIO_WiFi client in the WIFI section
+// #include "AdafruitIO_FONA.h"
+// AdafruitIO_FONA io(IO_USERNAME, IO_KEY);
+
+
+/**************************** ETHERNET ************************************/
+
+// the AdafruitIO_Ethernet client will work with the following boards:
+//   - Ethernet FeatherWing -> https://www.adafruit.com/products/3201
+
+// uncomment the following two lines for ethernet,
+// and comment out the AdafruitIO_WiFi client in the WIFI section
+// #include "AdafruitIO_Ethernet.h"
+// AdafruitIO_Ethernet io(IO_USERNAME, IO_KEY);

examples/adafruitio_21_feed_read/adafruitio_21_feed_read.ino

@@ -0,0 +1,78 @@
+// Adafruit IO Feed Reading
+// Tutorial Link: https://learn.adafruit.com/adafruit-io-basics-feeds/sharing-a-feed
+//
+// Adafruit invests time and resources providing this open source code.
+// Please support Adafruit and open source hardware by purchasing
+// products from Adafruit!
+//
+// Written by Brent Rubell for Adafruit Industries
+// Copyright (c) 2018 Adafruit Industries
+// Licensed under the MIT license.
+//
+// All text above must be included in any redistribution.
+
+/************************** Configuration ***********************************/
+
+// edit the config.h tab and enter your Adafruit IO credentials
+// and any additional configuration needed for WiFi, cellular,
+// or ethernet clients.
+#include "config.h"
+
+/************************ Example Starts Here *******************************/
+
+// the Adafruit IO username of whomever owns the feed
+#define FEED_OWNER "AIO_FEED_OWNER"
+
+// set up the `sharedFeed`
+AdafruitIO_Feed *sharedFeed = io.feed("FEED-NAME", FEED_OWNER);
+
+void setup() {
+  
+  // start the serial connection
+  Serial.begin(115200);
+
+  // wait for serial monitor to open
+  while(! Serial);
+
+  // connect to io.adafruit.com
+  Serial.print("Connecting to Adafruit IO");
+  io.connect();
+
+  // set up a message handler for the 'sharedFeed' feed.
+  // the handleMessage function (defined below)
+  // will be called whenever a message is
+  // received from adafruit io.
+  sharedFeed->onMessage(handleMessage);
+
+  // wait for a connection
+  while(io.status() < AIO_CONNECTED) {
+    Serial.print(".");
+    delay(500);
+  }
+
+  // we are connected
+  Serial.println();
+  Serial.println(io.statusText());
+  sharedFeed->get();
+
+}
+
+void loop() {
+
+  // io.run(); is required for all sketches.
+  // it should always be present at the top of your loop
+  // function. it keeps the client connected to
+  // io.adafruit.com, and processes any incoming data.
+  io.run();
+
+}
+
+// this function is called whenever an 'sharedFeed' feed message
+// is received from Adafruit IO. it was attached to
+// the 'digital' feed in the setup() function above.
+void handleMessage(AdafruitIO_Data *data) {
+
+  Serial.print("received <-  ");
+  Serial.println(data->toInt());
+  
+}

examples/adafruitio_21_feed_read/config.h

@@ -0,0 +1,44 @@
+/************************ Adafruit IO Config *******************************/
+
+// visit io.adafruit.com if you need to create an account,
+// or if you need your Adafruit IO key.
+#define IO_USERNAME    "your_username"
+#define IO_KEY         "your_key"
+
+/******************************* WIFI **************************************/
+
+// the AdafruitIO_WiFi client will work with the following boards:
+//   - HUZZAH ESP8266 Breakout -> https://www.adafruit.com/products/2471
+//   - Feather HUZZAH ESP8266 -> https://www.adafruit.com/products/2821
+//   - Feather HUZZAH ESP32 -> https://www.adafruit.com/product/3405
+//   - Feather M0 WiFi -> https://www.adafruit.com/products/3010
+//   - Feather WICED -> https://www.adafruit.com/products/3056
+
+#define WIFI_SSID       "your_ssid"
+#define WIFI_PASS       "your_pass"
+
+// comment out the following two lines if you are using fona or ethernet
+#include "AdafruitIO_WiFi.h"
+AdafruitIO_WiFi io(IO_USERNAME, IO_KEY, WIFI_SSID, WIFI_PASS);
+
+
+/******************************* FONA **************************************/
+
+// the AdafruitIO_FONA client will work with the following boards:
+//   - Feather 32u4 FONA -> https://www.adafruit.com/product/3027
+
+// uncomment the following two lines for 32u4 FONA,
+// and comment out the AdafruitIO_WiFi client in the WIFI section
+// #include "AdafruitIO_FONA.h"
+// AdafruitIO_FONA io(IO_USERNAME, IO_KEY);
+
+
+/**************************** ETHERNET ************************************/
+
+// the AdafruitIO_Ethernet client will work with the following boards:
+//   - Ethernet FeatherWing -> https://www.adafruit.com/products/3201
+
+// uncomment the following two lines for ethernet,
+// and comment out the AdafruitIO_WiFi client in the WIFI section
+// #include "AdafruitIO_Ethernet.h"
+// AdafruitIO_Ethernet io(IO_USERNAME, IO_KEY);

library.properties

@@ -1,5 +1,5 @@
 name=Adafruit IO Arduino
-version=2.7.9
+version=2.7.10
 author=Adafruit
 maintainer=Adafruit <[email protected]>
 sentence=Arduino library to access Adafruit IO.

src/AdafruitIO.cpp

@@ -78,6 +78,11 @@ AdafruitIO_Feed* AdafruitIO::feed(const char* name)
   return new AdafruitIO_Feed(this, name);
 }
 
+AdafruitIO_Feed* AdafruitIO::feed(const char* name, const char* owner)
+{
+  return new AdafruitIO_Feed(this, name, owner);
+}
+
 AdafruitIO_Time* AdafruitIO::time(aio_time_format_t format)
 {
   return new AdafruitIO_Time(this, format);

src/AdafruitIO.h

@@ -49,6 +49,7 @@ class AdafruitIO {
     void run(uint16_t busywait_ms = 0);
 
     AdafruitIO_Feed* feed(const char *name);
+    AdafruitIO_Feed* feed(const char *name, const char *owner);
     AdafruitIO_Group* group(const char *name);
     AdafruitIO_Dashboard* dashboard(const char *name);
     AdafruitIO_Time* time(aio_time_format_t format);

src/AdafruitIO_Feed.cpp

@@ -16,10 +16,16 @@ AdafruitIO_Feed::AdafruitIO_Feed(AdafruitIO *io, const char *n):AdafruitIO_MQTT(
 {
   _io = io;
   name = n;
-  _sub = 0;
-  _pub = 0;
-  _get_pub = 0;
-  _dataCallback = 0;
+  owner = _io->_username;
+
+  _init();
+}
+
+AdafruitIO_Feed::AdafruitIO_Feed(AdafruitIO *io, const char *n, const char *un):AdafruitIO_MQTT()
+{
+  _io = io;
+  name = n;
+  owner = un;
 
   _init();
 }
@@ -159,7 +165,7 @@ AdafruitIO_Data* AdafruitIO_Feed::lastValue()
 {
   // 15 extra for api path, 12 for /data/retain, 1 for null
   String url = "/api/v2/";
-  url += _io->_username;
+  url += owner;
   url += "/feeds/";
   url += name;
   url += "/data/retain";
@@ -181,6 +187,8 @@ AdafruitIO_Data* AdafruitIO_Feed::lastValue()
       return new AdafruitIO_Data(this, body.c_str());
     }
 
+    return NULL;
+
   } else {
 
     AIO_ERROR_PRINT("error retrieving lastValue, status: ");
@@ -209,37 +217,41 @@ void AdafruitIO_Feed::subCallback(char *val, uint16_t len)
 
 void AdafruitIO_Feed::_init()
 {
+  _sub = 0;
+  _pub = 0;
+  _get_pub = 0;
+  _dataCallback = 0;
 
   // dynamically allocate memory for mqtt topic and REST URLs
-  _topic = (char *) malloc(sizeof(char) * (strlen(_io->_username) + strlen(name) + 8)); // 8 extra chars for /f/, /csv & null termination
-  _get_topic = (char *) malloc(sizeof(char) * (strlen(_io->_username) + strlen(name) + 12)); // 12 extra chars for /f/, /csv/get & null termination
-  _feed_url = (char *) malloc(sizeof(char) * (strlen(_io->_username) + strlen(name) + 16)); // 16 extra for api path & null term
-  _create_url = (char *) malloc(sizeof(char) * (strlen(_io->_username) + 15)); // 15 extra for api path & null term
+  _topic = (char *) malloc(sizeof(char) * (strlen(owner) + strlen(name) + 8)); // 8 extra chars for /f/, /csv & null termination
+  _get_topic = (char *) malloc(sizeof(char) * (strlen(owner) + strlen(name) + 12)); // 12 extra chars for /f/, /csv/get & null termination
+  _feed_url = (char *) malloc(sizeof(char) * (strlen(owner) + strlen(name) + 16)); // 16 extra for api path & null term
+  _create_url = (char *) malloc(sizeof(char) * (strlen(owner) + 15)); // 15 extra for api path & null term
 
   // init feed data
   data = new AdafruitIO_Data(this);
 
   if(_topic && _create_url && _feed_url) {
 
     // build topic string
-    strcpy(_topic, _io->_username);
+    strcpy(_topic, owner);
     strcat(_topic, "/f/");
     strcat(_topic, name);
     strcat(_topic, "/csv");
 
     // build feed url string
     strcpy(_feed_url, "/api/v2/");
-    strcat(_feed_url, _io->_username);
+    strcat(_feed_url, owner);
     strcat(_feed_url, "/feeds/");
     strcat(_feed_url, name);
 
     // build create url string
     strcpy(_create_url, "/api/v2/");
-    strcat(_create_url, _io->_username);
+    strcat(_create_url, owner);
     strcat(_create_url, "/feeds");
 
     // build /get topic string
-    strcpy(_get_topic, _io->_username);
+    strcpy(_get_topic, owner);
     strcat(_get_topic, "/f/");
     strcat(_get_topic, name);
     strcat(_get_topic, "/csv/get");

src/AdafruitIO_Feed.h

@@ -25,6 +25,8 @@ class AdafruitIO_Feed : public AdafruitIO_MQTT {
 
   public:
     AdafruitIO_Feed(AdafruitIO *io, const char *name);
+    AdafruitIO_Feed(AdafruitIO *io, const char *name, const char *owner);
+
     ~AdafruitIO_Feed();
 
     bool save(char *value, double lat=0, double lon=0, double ele=0);
@@ -48,6 +50,7 @@ class AdafruitIO_Feed : public AdafruitIO_MQTT {
     void subCallback(char *val, uint16_t len);
 
     const char *name;
+    const char *owner;
 
     AdafruitIO_Data *lastValue();
     AdafruitIO_Data *data;