add support for PCF8574 gpio expansion

include/GPIOBank.h

 #ifndef _GPIO_BANK_H_
 #define _GPIO_BANK_H_
 
+void gpio_i2c_init(void);
+
 class GPIOBank {
 public:
     GPIOBank(int _size);

include/config_pins.h

 
 #ifdef FUNCTION_UI
 
+/*
+ * AVR UI
+ */
+
 #define SERIAL_LCD_TX_PIN 10
 
 #define KEYMATRIX_ROWS 4
 
 #ifdef FUNCTION_CONTROL
 
+/*
+ * AVR Controller
+ */
+
 // out 1, out 2, out 3, out 4, in
 #define VALVE_COUNT 5
 #define VALVE_PINS 10, 11, 12, 14, 15
 
 #ifdef FUNCTION_UI
 
+/*
+ * ESP UI
+ */
+
 #error configuration not supported
 
 #endif // FUNCTION_UI
 
 #ifdef FUNCTION_CONTROL
 
-#define PLANT_COUNT 4
-#define PLANT_PINS 27, 14, 5, 18
+/*
+ * ESP Controller
+ */
+
+/*
+ * I2C Port Expander PCF8574(A)
+ *
+ * Address ranges:
+ * PCF8574: 0x20 - 0x27
+ * PCF8574A: 0x38 - 0x3F
+ */
+#define I2C_GPIO_EXPANDER_COUNT 1
+#define I2C_GPIO_EXPANDER_ADDR 0x20
+
+/*
+ * GPIO Numbering Scheme
+ * 000 - 099: normal ESP32 GPIOs
+ * 100 - 228: consecutive I2C Expander GPIOs
+ */
+
+#define PLANT_COUNT 8
+#define PLANT_PINS 27, 14, 5, 18, 100, 101, 102, 103
 
 #define INLET_PIN 15
 

platformio.ini

     https://github.com/Links2004/arduinoWebSockets
     https://github.com/rlogiacco/CircularBuffer
     https://github.com/tobiasschuerg/InfluxDB-Client-for-Arduino.git
+    https://github.com/RobTillaart/PCF8574
 
 [env:arduino_ui]
 platform = atmelavr

src/Functionality.cpp

 
 #ifdef FUNCTION_CONTROL
 
-#ifndef FUNCTION_UI
 #include <Wire.h>
-#endif // ! FUNCTION_UI
 
 #include "Plants.h"
 #include "Statemachine.h"
 }
 
 void control_setup(void) {
-    plants.setValvePins(valve_pins);
-    plants.setPumpPins(pump_pins);
-    plants.setSwitchPins(switch_pins, true);
-    plants.setAuxPins(aux_pins);
-    
-#ifndef FUNCTION_UI
-    
     debug.println("Initializing I2C Master");
     Wire.setClock(I2C_BUS_SPEED);
     
     Wire.begin();
 #endif // defined(I2C_SDA_PIN) && defined(I2C_SCL_PIN)
     
+    gpio_i2c_init();
+
 #ifdef DEBUG_WAIT_FOR_SERIAL_CONN
     debug.println("Wait for Serial");
     while (!Serial);
 #endif // DEBUG_WAIT_FOR_SERIAL_CONN
-    
-#endif // ! FUNCTION_UI
+
+    debug.println("Initializing GPIOs");
+    plants.setValvePins(valve_pins);
+    plants.setPumpPins(pump_pins);
+    plants.setSwitchPins(switch_pins, true);
+    plants.setAuxPins(aux_pins);
 }
 
 void control_begin(void) {
     
     //debug.println("write_to_all i2c");
     
+    // rarely some lines don't update
+    delay(100);
+
     for (int i = 0; i < 4; i++) {
         Wire.beginTransmission(OWN_I2C_ADDRESS);
         Wire.write(0x03); // display command
-    
+
         Wire.write(i);
-        
+
         int l = strlen(lines[i]);
         Wire.write(l);
-        
+
         for (int n = 0; n < l; n++) {
             Wire.write(lines[i][n]);
         }
-    
+
         Wire.endTransmission();
     }
     
     Wire.beginTransmission(OWN_I2C_ADDRESS);
-    Wire.write(0x04); // display command
+    Wire.write(0x04); // button command
     Wire.write((int8_t)num_input);
     Wire.endTransmission();
     

src/GPIOBank.cpp

 #include <Arduino.h>
 
 #include "GPIOBank.h"
+#include "config.h"
+#include "config_pins.h"
 
 #ifdef PLATFORM_ESP
+#include <PCF8574.h>
+#include <Wire.h>
 #include "WifiStuff.h"
 #endif // PLATFORM_ESP
 
 //#define GPIO_HIGH_AS_INPUT
 
+// ----------------------------------------------------------------------------
+
+#if (I2C_GPIO_EXPANDER_COUNT > 0)
+static PCF8574 expand[I2C_GPIO_EXPANDER_COUNT];
+#endif
+
+void gpio_i2c_init(void) {
+#if (I2C_GPIO_EXPANDER_COUNT > 0)
+    for (int i = 0; i < I2C_GPIO_EXPANDER_COUNT; i++) {
+        expand[i].begin(0xFF);
+    }
+#endif
+}
+
+static void gpio_pinMode(int pin, int value) {
+    if (pin < 100) {
+        pinMode(pin, value);
+    } else {
+        pin -= 100;
+        int ex = pin / 8;
+        pin = pin % 8;
+        if (ex < I2C_GPIO_EXPANDER_COUNT) {
+            uint8_t mask = expand[ex].getButtonMask();
+            if (value == OUTPUT) {
+                mask &= ~(1 << pin);
+            } else {
+                mask |= (1 << pin);
+            }
+            expand[ex].setButtonMask(mask);
+        }
+    }
+}
+
+static void gpio_digitalWrite(int pin, int value) {
+    if (pin < 100) {
+        digitalWrite(pin, value);
+    } else {
+        pin -= 100;
+        int ex = pin / 8;
+        pin = pin % 8;
+        if (ex < I2C_GPIO_EXPANDER_COUNT) {
+            expand[ex].write(pin, value);
+        }
+    }
+}
+
+static int gpio_digitalRead(int pin) {
+    if (pin < 100) {
+        return digitalRead(pin);
+    } else {
+        pin -= 100;
+        int ex = pin / 8;
+        pin = pin % 8;
+        if (ex < I2C_GPIO_EXPANDER_COUNT) {
+            return expand[ex].readButton(pin);
+        } else {
+            return 0;
+        }
+    }
+}
+
+// ----------------------------------------------------------------------------
+
 GPIOBank::GPIOBank(int _size) {
     size = _size;
     pins = new int[size];
 void GPIOBank::setOutput(void) {
     for (int i = 0; i < size; i++) {
 #ifdef GPIO_HIGH_AS_INPUT
-        pinMode(pins[i], INPUT);
+        gpio_pinMode(pins[i], INPUT);
 #else
-        pinMode(pins[i], OUTPUT);
-        digitalWrite(pins[i], HIGH);
+        gpio_pinMode(pins[i], OUTPUT);
+        gpio_digitalWrite(pins[i], HIGH);
 #endif
         out_state[i] = true;
     }
 void GPIOBank::setInput(bool pullup) {
     for (int i = 0; i < size; i++) {
         if (pullup) {
-            pinMode(pins[i], INPUT_PULLUP);
+            gpio_pinMode(pins[i], INPUT_PULLUP);
         } else {
-            pinMode(pins[i], INPUT);
+            gpio_pinMode(pins[i], INPUT);
         }
     }
     is_output = false;
     if ((n >= 0) && (n < size)) {
 #ifdef GPIO_HIGH_AS_INPUT
         if (state) {
-            pinMode(pins[n], OUTPUT);
-            digitalWrite(pins[n], LOW);
+            gpio_pinMode(pins[n], OUTPUT);
+            gpio_digitalWrite(pins[n], LOW);
         } else {
-            pinMode(pins[n], INPUT);
+            gpio_pinMode(pins[n], INPUT);
         }
 #else
-        digitalWrite(pins[n], (!state) ? HIGH : LOW);
+        gpio_digitalWrite(pins[n], (!state) ? HIGH : LOW);
 #endif
 
         out_state[n] = !state;
         if (is_output) {
             return !out_state[n];
         } else {
-            return (!digitalRead(pins[n]));
+            return (!gpio_digitalRead(pins[n]));
         }
     } else {
         return false;