[WiFi] added support for ESP32 architecture and XIAO ESP32C2 board

- support for ESP32 architecture with WiFi interface (WiFiStream, Firmata.h, StandardFirmataWiFi)
- support for Seed Studio XIAO ESP32C2 board (Board.h)
- support for Firmata applications without Servo.h (Boards.h, StandardFirmataWiFi)

Author: jnsbyr

Boards.h

@@ -2,6 +2,7 @@
   Boards.h - Hardware Abstraction Layer for Firmata library
   Copyright (c) 2006-2008 Hans-Christoph Steiner.  All rights reserved.
   Copyright (C) 2009-2017 Jeff Hoefs.  All rights reserved.
+  Copyright (C) 2023 Jens B. All rights reserved.
 
   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
@@ -10,7 +11,7 @@
 
   See file LICENSE.txt for further informations on licensing terms.
 
-  Last updated April 15th, 2018
+  Last updated December 17th, 2023
 */
 
 #ifndef Firmata_Boards_h
@@ -29,7 +30,16 @@
 // compile, but without support for any Servos.  Hopefully that's what the
 // user intended by not including Servo.h
 #ifndef MAX_SERVOS
-#define MAX_SERVOS 0
+  #define MAX_SERVOS 0
+  class Servo
+  {
+    public:
+      uint8_t attach(int pin) { return 0; };
+      uint8_t attach(int pin, int min, int max) { return 0; };
+      void detach() {};
+      void write(int value) {};
+      bool attached() { return false; };
+  };
 #endif
 
 /*
@@ -1021,6 +1031,29 @@ writePort(port, value, bitmask):  Write an 8 bit port.
 #define PIN_TO_SERVO(p)         (p)
 #define DEFAULT_PWM_RESOLUTION  10
 
+// XIAO ESP32C2
+// note: Firmata pin numbering schema is by ESP32 GPIO -> IS_XXX checks GPIO number
+#elif defined(ARDUINO_XIAO_ESP32C3)
+#define TOTAL_ANALOG_PINS       (A2 + 1)          // (max GPIOx + 1), there are 4 physical analog pins but only 3 are supported by ESP32 SDK 2.0.14 via ADC1
+#define TOTAL_PINS              NUM_DIGITAL_PINS  // (max GPIOx + 1), there are 11 physical pins
+#define PIN_SERIAL_RX           RX
+#define PIN_SERIAL_TX           TX
+#define IS_PIN_DIGITAL(p)       (((p) >= D0 && (p) <= D10) || (p) == D6 || (p) == D7)
+#define IS_PIN_ANALOG(p)        ((p) >= A0 && (p) <= A2)
+#define IS_PIN_PWM(p)           0
+#define IS_PIN_SERVO(p)         (IS_PIN_DIGITAL(p) && MAX_SERVOS > 0)
+#define IS_PIN_I2C(p)           ((p) == SDA || (p) == SCL)
+#define IS_PIN_SPI(p)           ((p) == SS || (p) == MOSI || (p) == MISO || (p) == SCK)
+#define IS_PIN_INTERRUPT(p)     (digitalPinToInterrupt(p) > NOT_AN_INTERRUPT)
+#define IS_PIN_SERIAL(p)        ((p) == PIN_SERIAL_RX || (p) == PIN_SERIAL_TX)
+#define PIN_TO_DIGITAL(p)       ((p) < 6? D0 + (p) : ((p) < 8? D6 + 6 - (p) : (p))) // Dx to GPIOy
+#define PIN_TO_ANALOG(p)        (p)                                                 // FIRMATAx to GPIOy
+#define PIN_TO_PWM(p)           127                                                 // @TODO ESP32 SDK does not support analogWrite()
+#define PIN_TO_SERVO(p)         127                                                 // @TODO ESP32 SDK does not support servos
+
+#define DEFAULT_PWM_RESOLUTION     8  // see esp32-hal-led.c, analog_resolution
+#define DEFAULT_ANALOG_RESOLUTION 12  // see esp32-hal-adc.h, analogSetWidth()
+
 // STM32 based boards
 #elif defined(ARDUINO_ARCH_STM32)
 #define TOTAL_ANALOG_PINS       NUM_ANALOG_INPUTS

Firmata.h

@@ -1,5 +1,5 @@
 /*
-  Firmata.h - Firmata library v2.5.8 - 2018-04-15
+  Firmata.h - Firmata library v2.5.10 - 2023-12-16
   Copyright (c) 2006-2008 Hans-Christoph Steiner.  All rights reserved.
   Copyright (C) 2009-2017 Jeff Hoefs.  All rights reserved.
 
@@ -38,7 +38,9 @@
 //#define INPUT                 0x00 // defined in Arduino.h
 //#define OUTPUT                0x01 // defined in Arduino.h
 // DEPRECATED as of Firmata v2.5
-#define ANALOG                  0x02 // same as PIN_MODE_ANALOG
+#ifndef ARDUINO_ARCH_ESP32
+  #define ANALOG                0x02 // same as PIN_MODE_ANALOG
+#endif
 #define PWM                     0x03 // same as PIN_MODE_PWM
 #define SERVO                   0x04 // same as PIN_MODE_SERVO
 #define SHIFT                   0x05 // same as PIN_MODE_SHIFT

FirmataConstants.h

@@ -21,7 +21,7 @@ namespace firmata {
  */
 static const int FIRMWARE_MAJOR_VERSION =  2;
 static const int FIRMWARE_MINOR_VERSION =  5;
-static const int FIRMWARE_BUGFIX_VERSION = 7;
+static const int FIRMWARE_BUGFIX_VERSION = 10;
 
 /* Version numbers for the protocol.  The protocol is still changing, so these
  * version numbers are important.

examples/StandardFirmataWiFi/StandardFirmataWiFi.ino

@@ -22,7 +22,7 @@
 
   See file LICENSE.txt for further informations on licensing terms.
 
-  Last updated August 17th, 2017
+  Last updated December 17th, 2023
 */
 
 /*
@@ -74,7 +74,11 @@
   - Arduino Mega: (D5, D7, D10, D50, D52, D53)
 */
 
-#include <Servo.h>
+#ifndef ARDUINO_ARCH_ESP32
+  // NOTE: ESP32 SKD does not provide an implementation for class Servo
+  //       -> requires a skeleton implementation for Servo in Boards.h to be able to compile
+  #include <Servo.h>
+#endif
 #include <Wire.h>
 #include <Firmata.h>
 
@@ -235,8 +239,10 @@ void detachServo(byte pin)
   } else if (servoCount > 0) {
     // keep track of detached servos because we want to reuse their indexes
     // before incrementing the count of attached servos
-    detachedServoCount++;
-    detachedServos[detachedServoCount - 1] = servoPinMap[pin];
+    if (detachedServoCount < MAX_SERVOS) {
+      detachedServos[detachedServoCount] = servoPinMap[pin];
+      detachedServoCount++;
+    }
   }
 
   servoPinMap[pin] = 255;
@@ -370,7 +376,7 @@ void setPinModeCallback(byte pin, int mode)
     reportAnalogCallback(PIN_TO_ANALOG(pin), mode == PIN_MODE_ANALOG ? 1 : 0); // turn on/off reporting
   }
   if (IS_PIN_DIGITAL(pin)) {
-    if (mode == INPUT || mode == PIN_MODE_PULLUP) {
+    if (mode == PIN_MODE_INPUT || mode == PIN_MODE_PULLUP) {
       portConfigInputs[pin / 8] |= (1 << (pin & 7));
     } else {
       portConfigInputs[pin / 8] &= ~(1 << (pin & 7));
@@ -390,14 +396,14 @@ void setPinModeCallback(byte pin, int mode)
         Firmata.setPinMode(pin, PIN_MODE_ANALOG);
       }
       break;
-    case INPUT:
+    case PIN_MODE_INPUT:
       if (IS_PIN_DIGITAL(pin)) {
         pinMode(PIN_TO_DIGITAL(pin), INPUT);    // disable output driver
 #if ARDUINO <= 100
         // deprecated since Arduino 1.0.1 - TODO: drop support in Firmata 2.6
         digitalWrite(PIN_TO_DIGITAL(pin), LOW); // disable internal pull-ups
 #endif
-        Firmata.setPinMode(pin, INPUT);
+        Firmata.setPinMode(pin, PIN_MODE_INPUT);
       }
       break;
     case PIN_MODE_PULLUP:
@@ -407,14 +413,14 @@ void setPinModeCallback(byte pin, int mode)
         Firmata.setPinState(pin, 1);
       }
       break;
-    case OUTPUT:
+    case PIN_MODE_OUTPUT:
       if (IS_PIN_DIGITAL(pin)) {
         if (Firmata.getPinMode(pin) == PIN_MODE_PWM) {
           // Disable PWM if pin mode was previously set to PWM.
           digitalWrite(PIN_TO_DIGITAL(pin), LOW);
         }
         pinMode(PIN_TO_DIGITAL(pin), OUTPUT);
-        Firmata.setPinMode(pin, OUTPUT);
+        Firmata.setPinMode(pin, PIN_MODE_OUTPUT);
       }
       break;
     case PIN_MODE_PWM:
@@ -461,7 +467,7 @@ void setPinModeCallback(byte pin, int mode)
 void setPinValueCallback(byte pin, int value)
 {
   if (pin < TOTAL_PINS && IS_PIN_DIGITAL(pin)) {
-    if (Firmata.getPinMode(pin) == OUTPUT) {
+    if (Firmata.getPinMode(pin) == PIN_MODE_OUTPUT) {
       Firmata.setPinState(pin, value);
       digitalWrite(PIN_TO_DIGITAL(pin), value);
     }
@@ -498,11 +504,11 @@ void digitalWriteCallback(byte port, int value)
       // do not disturb non-digital pins (eg, Rx & Tx)
       if (IS_PIN_DIGITAL(pin)) {
         // do not touch pins in PWM, ANALOG, SERVO or other modes
-        if (Firmata.getPinMode(pin) == OUTPUT || Firmata.getPinMode(pin) == INPUT) {
+        if (Firmata.getPinMode(pin) == PIN_MODE_OUTPUT || Firmata.getPinMode(pin) == PIN_MODE_INPUT) {
           pinValue = ((byte)value & mask) ? 1 : 0;
-          if (Firmata.getPinMode(pin) == OUTPUT) {
+          if (Firmata.getPinMode(pin) == PIN_MODE_OUTPUT) {
             pinWriteMask |= mask;
-          } else if (Firmata.getPinMode(pin) == INPUT && pinValue == 1 && Firmata.getPinState(pin) != 1) {
+          } else if (Firmata.getPinMode(pin) == PIN_MODE_INPUT && pinValue == 1 && Firmata.getPinState(pin) != 1) {
             // only handle INPUT here for backwards compatibility
 #if ARDUINO > 100
             pinMode(pin, INPUT_PULLUP);
@@ -725,22 +731,26 @@ void sysexCallback(byte command, byte argc, byte *argv)
       Firmata.write(CAPABILITY_RESPONSE);
       for (byte pin = 0; pin < TOTAL_PINS; pin++) {
         if (IS_PIN_DIGITAL(pin)) {
-          Firmata.write((byte)INPUT);
+          Firmata.write((byte)PIN_MODE_INPUT);
           Firmata.write(1);
           Firmata.write((byte)PIN_MODE_PULLUP);
           Firmata.write(1);
-          Firmata.write((byte)OUTPUT);
+          Firmata.write((byte)PIN_MODE_OUTPUT);
           Firmata.write(1);
         }
         if (IS_PIN_ANALOG(pin)) {
           Firmata.write(PIN_MODE_ANALOG);
+        #ifdef DEFAULT_ANALOG_RESOLUTION
+          Firmata.write(DEFAULT_ANALOG_RESOLUTION);
+        #else
           Firmata.write(10); // 10 = 10-bit resolution
+        #endif
         }
         if (IS_PIN_PWM(pin)) {
           Firmata.write(PIN_MODE_PWM);
           Firmata.write(DEFAULT_PWM_RESOLUTION);
         }
-        if (IS_PIN_DIGITAL(pin)) {
+        if (IS_PIN_SERVO(pin)) {
           Firmata.write(PIN_MODE_SERVO);
           Firmata.write(14);
         }
@@ -820,7 +830,7 @@ void systemResetCallback()
       setPinModeCallback(i, PIN_MODE_ANALOG);
     } else if (IS_PIN_DIGITAL(i)) {
       // sets the output to 0, configures portConfigInputs
-      setPinModeCallback(i, OUTPUT);
+      setPinModeCallback(i, PIN_MODE_OUTPUT);
     }
 
     servoPinMap[i] = 255;
@@ -871,6 +881,7 @@ void printWifiStatus() {
     DEBUG_PRINT( "WiFi connection failed. Status value: " );
     DEBUG_PRINTLN( WiFi.status() );
   }
+#ifdef SERIAL_DEBUG
   else
   {
     // print the SSID of the network you're attached to:
@@ -888,6 +899,7 @@ void printWifiStatus() {
     DEBUG_PRINT( rssi );
     DEBUG_PRINTLN( " dBm" );
   }
+#endif
 }
 
 /*

examples/StandardFirmataWiFi/wifiConfig.h

@@ -8,8 +8,8 @@
  *============================================================================*/
 
 // STEP 1 [REQUIRED]
-// Uncomment / comment the appropriate set of includes for your hardware (OPTION A, B or C)
-// Arduino MKR1000 or ESP8266 are enabled by default if compiling for either of those boards.
+// Uncomment / comment the appropriate set of includes for your hardware (OPTION A ... F)
+// Arduino MKR1000, ESP8266 and ESP32 are enabled by default if compiling for either of those boards.
 
 /*
  * OPTION A: Configure for Arduino MKR1000 or Arduino WiFi Shield 101
@@ -137,6 +137,31 @@
   #endif
 #endif
 
+/*
+ * OPTION F: Configure for ESP32
+ *
+ * This will configure StandardFirmataWiFi to use the ESP8266WiFi library for boards
+ * with an ESP32 chip.
+ *
+ * The appropriate libraries are included automatically when compiling for the ESP32 so
+ * continue on to STEP 2.
+ */
+
+#if defined(ARDUINO_ARCH_ESP32)
+  // automatically include if compiling for ESP32
+  #define ESP32_WIFI
+#endif
+#ifdef ESP32_WIFI
+  #include <WiFi.h>
+  #include "utility/WiFiClientStream.h"
+  #include "utility/WiFiServerStream.h"
+  #ifdef WIFI_LIB_INCLUDED
+    #define MULTIPLE_WIFI_LIB_INCLUDES
+  #else
+    #define WIFI_LIB_INCLUDED
+  #endif
+#endif
+
 //------------------------------
 // TODO
 //------------------------------

library.properties

@@ -1,5 +1,5 @@
 name=Firmata
-version=2.5.9
+version=2.5.10
 author=Firmata Developers
 maintainer=Firmata team
 sentence=Enables the communication with computer apps using a standard serial protocol. For all Arduino/Genuino boards.

utility/WiFiStream.h

@@ -6,7 +6,7 @@
   are compatible with the Arduino WiFi library.
 
   Copyright (C) 2015-2016 Jesse Frush. All rights reserved.
-  Copyright (C) 2016      Jens B. All rights reserved.
+  Copyright (C) 2016 Jens B. All rights reserved.
 
   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
@@ -15,7 +15,7 @@
 
   See file LICENSE.txt for further informations on licensing terms.
 
-  Last updated April 23rd, 2016
+  Last updated December 17th, 2023
  */
 
 #ifndef WIFI_STREAM_H
@@ -69,7 +69,7 @@ class WiFiStream : public Stream
  *           network configuration
  ******************************************************************************/
 
-#ifndef ESP8266
+#if (!ESP8266) && (!ARDUINO_ARCH_ESP32)
   /**
    * configure a static local IP address without defining the local network
    * DHCP will be used as long as local IP address is not defined
@@ -90,7 +90,7 @@ class WiFiStream : public Stream
     _local_ip = local_ip;
     _subnet = subnet;
     _gateway = gateway;
-#ifndef ESP8266
+#if (!ESP8266) && (!ARDUINO_ARCH_ESP32)
     WiFi.config( local_ip, IPAddress(0, 0, 0, 0), gateway, subnet );
 #else
     WiFi.config( local_ip, gateway, subnet );
@@ -135,6 +135,14 @@ class WiFiStream : public Stream
   {
     return _client.status();
   }
+#elif ARDUINO_ARCH_ESP32
+  /**
+   * check if TCP connection is established
+   */
+  inline uint8_t connected()
+  {
+    return _client.connected();
+  }
 #endif
 
   /**
@@ -157,10 +165,10 @@ class WiFiStream : public Stream
 
     WiFi.begin(ssid);
     int result = WiFi.status();
-    return WiFi.status();
+    return result;
   }
 
-#ifndef ESP8266
+#if (!ESP8266) && (!ARDUINO_ARCH_ESP32)
   /**
    * initialize WiFi with WEP security and initiate client connection
    * if WiFi connection is already established