Add support for PCF8574 I2C port expander

- for Multi Relay usermod.

usermods/multi_relay/readme.md

@@ -1,6 +1,9 @@
 # Multi Relay
 
 This usermod-v2 modification allows the connection of multiple relays, each with individual delay and on/off mode.
+Usermod supports PCF8574 I2C port expander to reduce GPIO use.
+PCF8574 supports 8 outputs and each output corresponds to a relay in WLED (relay 0 = port 0, etc). I you are using more than 8 relays with multiple PCF8574 make sure their addresses are set conscutively (e.g. 0x20 and 0x21). You can set address of first expander in settings.
+(**NOTE:** Will require Wire library and global I2C pins defined.)
 
 ## HTTP API
 All responses are returned in JSON format. 
@@ -81,13 +84,15 @@ void registerUsermods()
 Usermod can be configured via the Usermods settings page.
 
 * `enabled` - enable/disable usermod
+* `use-PCF8574` - use PCF8574 port expander instead of GPIO pins
+* `first-PCF8574` - I2C address of first expander (WARNING: enter *decimal* value)
+* `broadcast`- time in seconds between MQTT relay-state broadcasts
+* `HA-discovery`- enable Home Assistant auto discovery
 * `pin` - ESP GPIO pin the relay is connected to (can be configured at compile time `-D MULTI_RELAY_PINS=xx,xx,...`)
 * `delay-s` - delay in seconds after on/off command is received
 * `active-high` - assign high/low activation of relay (can be used to reverse relay states)
 * `external` - if enabled, WLED does not control relay, it can only be triggered by an external command (MQTT, HTTP, JSON or button)
 * `button` - button (from LED Settings) that controls this relay
-* `broadcast`- time in seconds between MQTT relay-state broadcasts
-* `HA-discovery`- enable Home Assistant auto discovery
 
 If there is no MultiRelay section, just save current configuration and re-open Usermods settings page. 
 
@@ -100,3 +105,6 @@ Have fun - @blazoncek
 2021-11
 * Added information about dynamic configuration options
 * Added button support.
+
+2023-05
+* Added support for PCF8574 I2C port expander (multiple)

usermods/multi_relay/usermod_multi_relay.h

@@ -4,6 +4,11 @@
 
 #ifndef MULTI_RELAY_MAX_RELAYS
   #define MULTI_RELAY_MAX_RELAYS 4
+#else
+  #if MULTI_RELAY_MAX_RELAYS>16
+    #undef MULTI_RELAY_MAX_RELAYS
+    #define MULTI_RELAY_MAX_RELAYS 16
+  #endif
 #endif
 
 #ifndef MULTI_RELAY_PINS
@@ -15,21 +20,29 @@
 #define ON  true
 #define OFF false
 
+#ifndef PCF8574_ADDRESS
+  #define PCF8574_ADDRESS 0x20  // some may start at 0x38
+#endif
+
 /*
  * This usermod handles multiple relay outputs.
  * These outputs complement built-in relay output in a way that the activation can be delayed.
  * They can also activate/deactivate in reverse logic independently.
+ * 
+ * Written and maintained by @blazoncek
  */
 
 
 typedef struct relay_t {
   int8_t pin;
-  bool active;
+  struct { // reduces memory footprint
-  bool mode;
+    bool active   : 1;
-  bool state;
+    bool mode     : 1;
-  bool external;
+    bool state    : 1;
+    bool external : 1;
+    int8_t button : 4;
+  };
   uint16_t delay;
-  int8_t button;
 } Relay;
 
 
@@ -48,7 +61,8 @@ class MultiRelay : public Usermod {
     bool enabled = false;  // needs to be configured (no default config)
     // status of initialisation
     bool initDone = false;
-
+    bool usePcf8574  = false;
+    uint8_t addrPcf8574 = PCF8574_ADDRESS;
     bool HAautodiscovery = false;
 
     uint16_t periodicBroadcastSec = 60;
@@ -64,8 +78,127 @@ class MultiRelay : public Usermod {
     static const char _button[];
     static const char _broadcast[];
     static const char _HAautodiscovery[];
+    static const char _pcf8574[];
+    static const char _pcfAddress[];
 
-    void publishMqtt(int relay) {
+    void handleOffTimer();
+    void InitHtmlAPIHandle();
+    int getValue(String data, char separator, int index);
+    uint8_t getActiveRelayCount();
+
+    byte IOexpanderWrite(byte address, byte _data);
+    byte IOexpanderRead(int address);
+
+    void publishMqtt(int relay);
+#ifndef WLED_DISABLE_MQTT
+    void publishHomeAssistantAutodiscovery();
+#endif
+
+  public:
+    /**
+     * constructor
+     */
+    MultiRelay();
+
+    /**
+     * desctructor
+     */
+    ~MultiRelay() {}
+
+    /**
+     * Enable/Disable the usermod
+     */
+    inline void enable(bool enable) { enabled = enable; }
+
+    /**
+     * Get usermod enabled/disabled state
+     */
+    inline bool isEnabled() { return enabled; }
+
+    /**
+     * getId() allows you to optionally give your V2 usermod an unique ID (please define it in const.h!).
+     * This could be used in the future for the system to determine whether your usermod is installed.
+     */
+    inline uint16_t getId() { return USERMOD_ID_MULTI_RELAY; }
+
+    /**
+     * switch relay on/off
+     */
+    void switchRelay(uint8_t relay, bool mode);
+
+    /**
+     * toggle relay
+     */
+    inline void toggleRelay(uint8_t relay) {
+      switchRelay(relay, !_relay[relay].state);
+    }
+
+    /**
+     * setup() is called once at boot. WiFi is not yet connected at this point.
+     * You can use it to initialize variables, sensors or similar.
+     */
+    void setup();
+
+    /**
+     * connected() is called every time the WiFi is (re)connected
+     * Use it to initialize network interfaces
+     */
+    inline void connected() { InitHtmlAPIHandle(); }
+
+    /**
+     * loop() is called continuously. Here you can check for events, read sensors, etc.
+     */
+    void loop();
+
+#ifndef WLED_DISABLE_MQTT
+    bool onMqttMessage(char* topic, char* payload);
+    void onMqttConnect(bool sessionPresent);
+#endif
+
+    /**
+     * handleButton() can be used to override default button behaviour. Returning true
+     * will prevent button working in a default way.
+     * Replicating button.cpp
+     */
+    bool handleButton(uint8_t b);
+
+    /**
+     * addToJsonInfo() can be used to add custom entries to the /json/info part of the JSON API.
+     */
+    void addToJsonInfo(JsonObject &root);
+
+    /**
+     * addToJsonState() can be used to add custom entries to the /json/state part of the JSON API (state object).
+     * Values in the state object may be modified by connected clients
+     */
+    void addToJsonState(JsonObject &root);
+
+    /**
+     * readFromJsonState() can be used to receive data clients send to the /json/state part of the JSON API (state object).
+     * Values in the state object may be modified by connected clients
+     */
+    void readFromJsonState(JsonObject &root);
+
+    /**
+     * provide the changeable values
+     */
+    void addToConfig(JsonObject &root);
+
+    void appendConfigData();
+
+    /**
+     * restore the changeable values
+     * readFromConfig() is called before setup() to populate properties from values stored in cfg.json
+     * 
+     * The function should return true if configuration was successfully loaded or false if there was no configuration.
+     */
+    bool readFromConfig(JsonObject &root);
+};
+
+
+// class implementetion
+
+void MultiRelay::publishMqtt(int relay) {
 #ifndef WLED_DISABLE_MQTT
   //Check if MQTT Connected, otherwise it will crash the 8266
   if (WLED_MQTT_CONNECTED){
@@ -79,7 +212,7 @@ class MultiRelay : public Usermod {
 /**
  * switch off the strip if the delay has elapsed 
  */
-    void handleOffTimer() {
+void MultiRelay::handleOffTimer() {
   unsigned long now = millis();
   bool activeRelays = false;
   for (int i=0; i<MULTI_RELAY_MAX_RELAYS; i++) {
@@ -101,7 +234,7 @@ class MultiRelay : public Usermod {
  * https://github.com/gsieben/WLED/blob/master/usermods/GeoGab-Relays/usermod_GeoGab.h
  */
 #define GEOGABVERSION "0.1.3"
-    void InitHtmlAPIHandle() {  // https://github.com/me-no-dev/ESPAsyncWebServer
+void MultiRelay::InitHtmlAPIHandle() {  // https://github.com/me-no-dev/ESPAsyncWebServer
   DEBUG_PRINTLN(F("Relays: Initialize HTML API"));
 
   server.on("/relays", HTTP_GET, [this](AsyncWebServerRequest *request) {
@@ -163,7 +296,7 @@ class MultiRelay : public Usermod {
   });
 }
 
-    int getValue(String data, char separator, int index) {
+int MultiRelay::getValue(String data, char separator, int index) {
   int found = 0;
   int strIndex[] = {0, -1};
   int maxIndex = data.length()-1;
@@ -178,11 +311,27 @@ class MultiRelay : public Usermod {
   return found>index ? data.substring(strIndex[0], strIndex[1]).toInt() : -1;
 }
 
-  public:
+//Write a byte to the IO expander
-    /**
+byte MultiRelay::IOexpanderWrite(byte address, byte _data ) {
-     * constructor
+  Wire.beginTransmission(addrPcf8574 + address);
-     */
+  Wire.write(_data);
-    MultiRelay() {
+  return Wire.endTransmission(); 
+}
+
+//Read a byte from the IO expander
+byte MultiRelay::IOexpanderRead(int address) {
+  byte _data = 0;
+  Wire.requestFrom(addrPcf8574 + address, 1);
+  if (Wire.available()) {
+    _data = Wire.read();
+  }
+  return _data;
+}
+
+
+// public methods
+
+MultiRelay::MultiRelay() {
   const int8_t defPins[] = {MULTI_RELAY_PINS};
   for (size_t i=0; i<MULTI_RELAY_MAX_RELAYS; i++) {
     _relay[i].pin      = i<sizeof(defPins) ? defPins[i] : -1;
@@ -194,44 +343,35 @@ class MultiRelay : public Usermod {
     _relay[i].button   = -1;
   }
 }
-    /**
-     * desctructor
-     */
-    ~MultiRelay() {}
-
-    /**
-     * Enable/Disable the usermod
-     */
-    inline void enable(bool enable) { enabled = enable; }
-    /**
-     * Get usermod enabled/disabled state
-     */
-    inline bool isEnabled() { return enabled; }
 
 /**
  * switch relay on/off
  */
-    void switchRelay(uint8_t relay, bool mode) {
+void MultiRelay::switchRelay(uint8_t relay, bool mode) {
-      if (relay>=MULTI_RELAY_MAX_RELAYS || _relay[relay].pin<0) return;
+  if (relay>=MULTI_RELAY_MAX_RELAYS || (_relay[relay].pin<0 && !usePcf8574)) return;
   _relay[relay].state = mode;
+  if (usePcf8574) {
+    byte expander = relay/8;
+    uint16_t state = 0;
+    for (int i=0; i<MULTI_RELAY_MAX_RELAYS; i++) state |= (uint16_t)_relay[i].state << i; // fill relay states for all pins
+    state = (mode ? !_relay[relay].mode : _relay[relay].mode) ? state | (1<<relay) : state & ~(1<<relay); // take into account invert mode
+    IOexpanderWrite(expander, state>>(8*expander));
+    DEBUG_PRINT(F("PCF8574 Writing to ")); DEBUG_PRINT(addrPcf8574 + expander); DEBUG_PRINT(F(" with data ")); DEBUG_PRINTLN(state>>(8*expander));
+  } else {
     pinMode(_relay[relay].pin, OUTPUT);
     digitalWrite(_relay[relay].pin, mode ? !_relay[relay].mode : _relay[relay].mode);
+  }
   publishMqtt(relay);
 }
 
-    /**
+uint8_t MultiRelay::getActiveRelayCount() {
-     * toggle relay
-     */
-    inline void toggleRelay(uint8_t relay) {
-      switchRelay(relay, !_relay[relay].state);
-    }
-
-    uint8_t getActiveRelayCount() {
   uint8_t count = 0;
+  if (usePcf8574) return MULTI_RELAY_MAX_RELAYS;  // we don't know how many there are
   for (int i=0; i<MULTI_RELAY_MAX_RELAYS; i++) if (_relay[i].pin>=0) count++;
   return count;
 }
 
+
 //Functions called by WLED
 
 #ifndef WLED_DISABLE_MQTT
@@ -240,7 +380,7 @@ class MultiRelay : public Usermod {
  * topic only contains stripped topic (part after /wled/MAC)
  * topic should look like: /relay/X/command; where X is relay number, 0 based
  */
-    bool onMqttMessage(char* topic, char* payload) {
+bool MultiRelay::onMqttMessage(char* topic, char* payload) {
   if (strlen(topic) > 8 && strncmp_P(topic, PSTR("/relay/"), 7) == 0 && strncmp_P(topic+8, PSTR("/command"), 8) == 0) {
     uint8_t relay = strtoul(topic+7, NULL, 10);
     if (relay<MULTI_RELAY_MAX_RELAYS) {
@@ -263,7 +403,7 @@ class MultiRelay : public Usermod {
 /**
  * subscribe to MQTT topic for controlling relays
  */
-    void onMqttConnect(bool sessionPresent) {
+void MultiRelay::onMqttConnect(bool sessionPresent) {
   //(re)subscribe to required topics
   char subuf[64];
   if (mqttDeviceTopic[0] != 0) {
@@ -278,7 +418,7 @@ class MultiRelay : public Usermod {
   }
 }
 
-    void publishHomeAssistantAutodiscovery() {
+void MultiRelay::publishHomeAssistantAutodiscovery() {
   for (int i = 0; i < MULTI_RELAY_MAX_RELAYS; i++) {
     char uid[24], json_str[1024], buf[128];
     size_t payload_size;
@@ -322,8 +462,21 @@ class MultiRelay : public Usermod {
  * setup() is called once at boot. WiFi is not yet connected at this point.
  * You can use it to initialize variables, sensors or similar.
  */
-    void setup() {
+void MultiRelay::setup() {
   // pins retrieved from cfg.json (readFromConfig()) prior to running setup()
+  // if we want PCF8574 expander I2C pins need to be valid
+  if (i2c_sda == i2c_scl && i2c_sda == -1) usePcf8574 = false;
+
+  if (usePcf8574) {
+    uint16_t state = 0;
+    for (int i=0; i<MULTI_RELAY_MAX_RELAYS; i++) state |= (uint16_t)(_relay[i].external ? (_relay[i].mode ? !_relay[i].state : _relay[i].state) : (_relay[i].mode ? !offMode : offMode)) << i; // fill relay states for all pins
+    for (int i=0; i<MULTI_RELAY_MAX_RELAYS; i += 8) {
+      byte expander = i/8;
+      IOexpanderWrite(expander, state>>(8*expander));  // init expander (set all outputs)
+      delay(1);
+    }
+    DEBUG_PRINTLN(F("PCF8574(s) inited."));
+  } else {
     for (int i=0; i<MULTI_RELAY_MAX_RELAYS; i++) {
       if (_relay[i].pin<0) continue;
       if (!pinManager.allocatePin(_relay[i].pin,true, PinOwner::UM_MultiRelay)) {
@@ -334,22 +487,15 @@ class MultiRelay : public Usermod {
         _relay[i].active = false;
       }
     }
+  }
   _oldMode = offMode;
   initDone = true;
 }
 
-    /**
-     * connected() is called every time the WiFi is (re)connected
-     * Use it to initialize network interfaces
-     */
-    void connected() {
-      InitHtmlAPIHandle();
-    }
-
 /**
  * loop() is called continuously. Here you can check for events, read sensors, etc.
  */
-    void loop() {
+void MultiRelay::loop() {
   yield();
   if (!enabled || strip.isUpdating()) return;
 
@@ -362,7 +508,7 @@ class MultiRelay : public Usermod {
     _oldMode = offMode;
     _switchTimerStart = millis();
     for (int i=0; i<MULTI_RELAY_MAX_RELAYS; i++) {
-          if (_relay[i].pin>=0 && !_relay[i].external) _relay[i].active = true;
+      if ((_relay[i].pin>=0 || usePcf8574) && !_relay[i].external) _relay[i].active = true;
     }
   }
 
@@ -374,7 +520,7 @@ class MultiRelay : public Usermod {
  * will prevent button working in a default way.
  * Replicating button.cpp
  */
-    bool handleButton(uint8_t b) {
+bool MultiRelay::handleButton(uint8_t b) {
   yield();
   if (!enabled
     || buttonType[b] == BTN_TYPE_NONE
@@ -466,7 +612,7 @@ class MultiRelay : public Usermod {
 /**
  * addToJsonInfo() can be used to add custom entries to the /json/info part of the JSON API.
  */
-    void addToJsonInfo(JsonObject &root) {
+void MultiRelay::addToJsonInfo(JsonObject &root) {
   if (enabled) {
     JsonObject user = root["u"];
     if (user.isNull())
@@ -478,7 +624,7 @@ class MultiRelay : public Usermod {
 
     String uiDomString;
     for (int i=0; i<MULTI_RELAY_MAX_RELAYS; i++) {
-          if (_relay[i].pin<0 || !_relay[i].external) continue;
+      if ((_relay[i].pin<0 && !usePcf8574) || !_relay[i].external) continue;
       uiDomString = F("Relay "); uiDomString += i;
       JsonArray infoArr = user.createNestedArray(uiDomString); // timer value
 
@@ -503,7 +649,7 @@ class MultiRelay : public Usermod {
  * addToJsonState() can be used to add custom entries to the /json/state part of the JSON API (state object).
  * Values in the state object may be modified by connected clients
  */
-    void addToJsonState(JsonObject &root) {
+void MultiRelay::addToJsonState(JsonObject &root) {
   if (!initDone || !enabled) return;  // prevent crash on boot applyPreset()
   JsonObject multiRelay = root[FPSTR(_name)];
   if (multiRelay.isNull()) {
@@ -527,7 +673,7 @@ class MultiRelay : public Usermod {
  * readFromJsonState() can be used to receive data clients send to the /json/state part of the JSON API (state object).
  * Values in the state object may be modified by connected clients
  */
-    void readFromJsonState(JsonObject &root) {
+void MultiRelay::readFromJsonState(JsonObject &root) {
   if (!initDone || !enabled) return;  // prevent crash on boot applyPreset()
   JsonObject usermod = root[FPSTR(_name)];
   if (!usermod.isNull()) {
@@ -557,11 +703,14 @@ class MultiRelay : public Usermod {
 /**
  * provide the changeable values
  */
-    void addToConfig(JsonObject &root) {
+void MultiRelay::addToConfig(JsonObject &root) {
   JsonObject top = root.createNestedObject(FPSTR(_name));
 
   top[FPSTR(_enabled)] = enabled;
+  top[FPSTR(_pcf8574)] = usePcf8574;
+  top[FPSTR(_pcfAddress)] = addrPcf8574;
   top[FPSTR(_broadcast)] = periodicBroadcastSec;
+  top[FPSTR(_HAautodiscovery)] = HAautodiscovery;
   for (int i=0; i<MULTI_RELAY_MAX_RELAYS; i++) {
     String parName = FPSTR(_relay_str); parName += '-'; parName += i;
     JsonObject relay = top.createNestedObject(parName);
@@ -571,17 +720,22 @@ class MultiRelay : public Usermod {
     relay[FPSTR(_external)]   = _relay[i].external;
     relay[FPSTR(_button)]     = _relay[i].button;
   }
-      top[FPSTR(_HAautodiscovery)] = HAautodiscovery;
   DEBUG_PRINTLN(F("MultiRelay config saved."));
 }
 
+void MultiRelay::appendConfigData() {
+  oappend(SET_F("addInfo('MultiRelay:first-PCF8574',1,'<i>(not hex!)</i>','address');"));
+  oappend(SET_F("addInfo('MultiRelay:broadcast-sec',1,'(MQTT message)');"));
+  oappend(SET_F("addInfo('MultiRelay:relay-0:pin',1,'(use -1 for PCF8574)');"));
+}
+
 /**
  * restore the changeable values
  * readFromConfig() is called before setup() to populate properties from values stored in cfg.json
  * 
  * The function should return true if configuration was successfully loaded or false if there was no configuration.
  */
-    bool readFromConfig(JsonObject &root) {
+bool MultiRelay::readFromConfig(JsonObject &root) {
   int8_t oldPin[MULTI_RELAY_MAX_RELAYS];
 
   JsonObject top = root[FPSTR(_name)];
@@ -591,7 +745,13 @@ class MultiRelay : public Usermod {
     return false;
   }
 
+  //bool configComplete = !top.isNull();
+  //configComplete &= getJsonValue(top[FPSTR(_enabled)], enabled);
   enabled = top[FPSTR(_enabled)] | enabled;
+  usePcf8574 = top[FPSTR(_pcf8574)] | usePcf8574;
+  addrPcf8574 = top[FPSTR(_pcfAddress)] | addrPcf8574;
+  // if I2C is not globally initialised just ignore
+  if (i2c_sda == i2c_scl && i2c_sda == -1) usePcf8574 = false;
   periodicBroadcastSec = top[FPSTR(_broadcast)] | periodicBroadcastSec;
   periodicBroadcastSec = min(900,max(0,(int)periodicBroadcastSec));
   HAautodiscovery = top[FPSTR(_HAautodiscovery)] | HAautodiscovery;
@@ -640,19 +800,9 @@ class MultiRelay : public Usermod {
     DEBUG_PRINTLN(F(" config (re)loaded."));
   }
   // use "return !top["newestParameter"].isNull();" when updating Usermod with new features
-      return !top[FPSTR(_HAautodiscovery)].isNull();
+  return !top[FPSTR(_pcf8574)].isNull();
 }
 
-    /**
-     * getId() allows you to optionally give your V2 usermod an unique ID (please define it in const.h!).
-     * This could be used in the future for the system to determine whether your usermod is installed.
-     */
-    uint16_t getId()
-    {
-      return USERMOD_ID_MULTI_RELAY;
-    }
-};
-
 // strings to reduce flash memory usage (used more than twice)
 const char MultiRelay::_name[]            PROGMEM = "MultiRelay";
 const char MultiRelay::_enabled[]         PROGMEM = "enabled";
@@ -663,3 +813,5 @@ const char MultiRelay::_external[]   PROGMEM = "external";
 const char MultiRelay::_button[]          PROGMEM = "button";
 const char MultiRelay::_broadcast[]       PROGMEM = "broadcast-sec";
 const char MultiRelay::_HAautodiscovery[] PROGMEM = "HA-autodiscovery";
+const char MultiRelay::_pcf8574[]         PROGMEM = "use-PCF8574";
+const char MultiRelay::_pcfAddress[]      PROGMEM = "first-PCF8574";