ESP32 platform support

Author: pstolarz

README.md

@@ -45,6 +45,9 @@ devices (e.g. Dallas/Maxim thermometers).
 * Arduino ESP8266.
     * Platform class: `OneWireNg_ArduinoESP8266`.
     * **Not tested**.
+* Arduino ESP32.
+    * Platform class: `OneWireNg_ArduinoESP32`.
+    * **Not tested**.
 
 NOTE: Expect more platforms support in the future. **I'm inviting all developers**,
 eager to help me with porting and testing the library for new platforms.

library.json

@@ -13,7 +13,7 @@
         "type": "git",
         "url": "https://github.com/pstolarz/OneWireNg"
     },
-    "version": "0.1.0",
+    "version": "0.2.0",
     "homepage": "https://github.com/pstolarz/OneWireNg",
     "frameworks": "Arduino",
     "examples": [

library.properties

@@ -1,9 +1,9 @@
 name=OneWireNg
-version=0.1.0
+version=0.2.0
 author=Piotr Stolarz
 maintainer=Piotr Stolarz <pstolarz@o2.pl>
 sentence=Arduino 1-wire service library
 paragraph=An alternative for the classic Arduino OneWire library providing: (1) fixed handling of the 1-wire bus low-level activities related to its open-drain characteristic, (2) new I/O interface with enhanced parasite powering support, (3) improved overall software architecture.
 category=Communication
 url=https://github.com/pstolarz/OneWireNg
-architectures=avr,megaavr,esp8266
+architectures=avr,megaavr,esp8266,esp32

src/OneWireNg_ArduinoESP32.h

@@ -0,0 +1,159 @@
+/*
+ * Copyright (c) 2019 Piotr Stolarz
+ * OneWireNg: Ardiono 1-wire service library
+ *
+ * Distributed under the 2-clause BSD License (the License)
+ * see accompanying file LICENSE for details.
+ *
+ * This software is distributed WITHOUT ANY WARRANTY; without even the
+ * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the License for more information.
+ */
+
+#ifndef __OWNG_ARDUINO_ESP32__
+#define __OWNG_ARDUINO_ESP32__
+
+#include <assert.h>
+#include "Arduino.h"
+#include "OneWireNg_BitBang.h"
+
+#define __READ_GPIO(pin) \
+    (pin < 32 ? ((GPIO.in >> pin) & 0x01) : \
+         pin < 40 ? ((GPIO.in1.val >> (pin - 32)) & 0x01) : 1)
+
+#define __WRITE_GPIO(pin, st) \
+    if (pin < 32) { \
+        if (st) GPIO.out_w1ts = ((uint32_t)1 << pin); \
+        else GPIO.out_w1tc = ((uint32_t)1 << pin); \
+    } else \
+    if (pin < 34) { \
+        if (st) GPIO.out1_w1ts.val = ((uint32_t)1 << (pin - 32)); \
+        else GPIO.out1_w1tc.val = ((uint32_t)1 << (pin - 32)); \
+    }
+
+#define __GPIO_AS_INPUT(pin) \
+    if(pin < 32) { \
+        GPIO.enable_w1tc = ((uint32_t)1 << pin); \
+    } else \
+    if (pin < 40) { \
+        GPIO.enable1_w1tc.val = ((uint32_t)1 << (pin - 32)); \
+    }
+
+#define __GPIO_AS_OUTPUT(pin) \
+    if (pin < 32) { \
+        GPIO.enable_w1ts = ((uint32_t)1 << pin); \
+    } else \
+    if (pin < 34) { \
+        GPIO.enable1_w1ts.val = ((uint32_t)1 << (pin - 32)); \
+    }
+
+/**
+ * Arduino ESP32 platform GPIO specific implementation.
+ */
+class OneWireNg_ArduinoESP32: public OneWireNg_BitBang
+{
+public:
+    /**
+     * OneWireNg 1-wire service for Arduino ESP32 platform.
+     *
+     * Bus powering is supported via switching its GPIO to the high state.
+     * In this case the GPIO servers as a voltage source for connected slaves
+     * working in parasite powering configuration.
+     *
+     * @param pin Arduino GPIO pin number used for bit-banging 1-wire bus.
+     * @param pullUp If @c true configure internal pull-up resistor for the bus.
+     */
+    OneWireNg_ArduinoESP32(unsigned pin, bool pullUp):
+        OneWireNg_BitBang(false)
+    {
+        /* pins above 33 can only be inputs */
+        assert(pin < 34);
+
+        _dtaPin = pin;
+        initDtaGpio(pullUp);
+    }
+
+    /**
+     * OneWireNg 1-wire service for Arduino ESP32 platform.
+     *
+     * Bus powering is supported via a switching transistor providing
+     * the power to the bus and controlled by a dedicated GPIO (see @sa
+     * OneWireNg_BitBang::setupPwrCtrlGpio()). In this configuration the
+     * service mimics the open-drain type of output. The approach may be
+     * feasible if the GPIO is unable to provide sufficient power for
+     * connected slaves working in parasite powering configuration.
+     *
+     * @param pin Arduino GPIO pin number used for bit-banging 1-wire bus.
+     * @param pwrCtrlPin Arduino GPIO pin number controlling the switching
+     *     transistor.
+     * @param pullUp If @c true configure internal pull-up resistor for the bus.
+     */
+    OneWireNg_ArduinoESP32(unsigned pin, unsigned pwrCtrlPin, bool pullUp):
+        OneWireNg_BitBang(true)
+    {
+        /* pins above 33 can only be inputs */
+        assert(pin < 40 && pwrCtrlPin < 34);
+
+        _dtaPin = pin;
+        _pwrCtrlPin = pwrCtrlPin;
+
+        initDtaGpio(pullUp);
+        initPwrCtrlGpio();
+    }
+
+protected:
+    virtual int readGpioIn(GpioType gpio)
+    {
+        UNUSED(gpio);
+        return __READ_GPIO(_dtaPin);
+    }
+
+    virtual void writeGpioOut(GpioType gpio, int state)
+    {
+        if (gpio == GPIO_DTA) {
+            __WRITE_GPIO(_dtaPin, state);
+        } else {
+            __WRITE_GPIO(_pwrCtrlPin, state);
+        }
+    }
+
+    virtual void setGpioAsInput(GpioType gpio)
+    {
+        UNUSED(gpio);
+        __GPIO_AS_INPUT(_dtaPin);
+    }
+
+    virtual void setGpioAsOutput(GpioType gpio, int state)
+    {
+        if (gpio == GPIO_DTA) {
+            __GPIO_AS_OUTPUT(_dtaPin);
+            __WRITE_GPIO(_dtaPin, state);
+        } else {
+            __GPIO_AS_OUTPUT(_pwrCtrlPin);
+            __WRITE_GPIO(_pwrCtrlPin, state);
+        }
+    }
+
+    void initDtaGpio(bool pullUp)
+    {
+        pinMode(_dtaPin, INPUT | (pullUp ? PULLUP : 0));
+        setupDtaGpio();
+    }
+
+    void initPwrCtrlGpio(void)
+    {
+        pinMode(_pwrCtrlPin, OUTPUT);
+        setupPwrCtrlGpio(true);
+    }
+
+private:
+    unsigned _dtaPin;
+    unsigned _pwrCtrlPin;
+};
+
+#undef __GPIO_AS_OUTPUT
+#undef __GPIO_AS_INPUT
+#undef __WRITE_GPIO
+#undef __READ_GPIO
+
+#endif /* __OWNG_ARDUINO_ESP32__ */

src/OneWireNg_CurrentPlatform.h

@@ -26,6 +26,9 @@
 #elif defined(ARDUINO_ARCH_ESP8266)
 # include "OneWireNg_ArduinoESP8266.h"
 # define OneWireNg_CurrentPlatform OneWireNg_ArduinoESP8266
+#elif defined(ARDUINO_ARCH_ESP32)
+# include "OneWireNg_ArduinoESP32.h"
+# define OneWireNg_CurrentPlatform OneWireNg_ArduinoESP32
 #else
 # define OneWireNg_CurrentPlatform
 # warning "Can't detect platform. Use proper class for the platform you are compiling for!"