Refactor to use PIO-specific driver on RP2040 platforms, rather than bitbang it

clean up

max 7

clang

Author: brentru

src/components/ds18x20/controller.cpp

@@ -19,14 +19,20 @@
     @brief  DS18X20Controller constructor
 */
 /***********************************************************************/
-DS18X20Controller::DS18X20Controller() { _DS18X20_model = new DS18X20Model(); }
+DS18X20Controller::DS18X20Controller() {
+  _num_drivers = 0;
+  _DS18X20_model = new DS18X20Model();
+}
 
 /***********************************************************************/
 /*!
     @brief  DS18X20Controller destructor
 */
 /***********************************************************************/
-DS18X20Controller::~DS18X20Controller() { delete _DS18X20_model; }
+DS18X20Controller::~DS18X20Controller() {
+  _num_drivers = 0;
+  delete _DS18X20_model;
+}
 
 /***********************************************************************/
 /*!
@@ -59,7 +65,8 @@ bool DS18X20Controller::Handle_Ds18x20Add(pb_istream_t *stream) {
   uint8_t pin_name = atoi(_DS18X20_model->GetDS18x20AddMsg()->onewire_pin + 1);
 
   // Initialize the DS18X20Hardware object
-  auto new_dsx_driver = std::make_unique<DS18X20Hardware>(pin_name);
+  auto new_dsx_driver =
+      std::make_unique<DS18X20Hardware>(pin_name, _num_drivers);
   // Attempt to get the sensor's ID on the OneWire bus to show it's been init'd
   bool is_initialized = new_dsx_driver->GetSensor();
 
@@ -95,8 +102,10 @@ bool DS18X20Controller::Handle_Ds18x20Add(pb_istream_t *stream) {
     }
 
     // If the sensor was successfully initialized, add it to the controller
-    if (is_initialized == true)
+    if (is_initialized == true) {
       _DS18X20_pins.push_back(std::move(new_dsx_driver));
+      _num_drivers++;
+    }
 
     // Print out the details
     WS_DEBUG_PRINTLN("[ds18x] New Sensor Added!");
@@ -172,6 +181,7 @@ bool DS18X20Controller::Handle_Ds18x20Remove(pb_istream_t *stream) {
     }
   }
   WS_DEBUG_PRINTLN("Removed!");
+  _num_drivers--;
   return true;
 }
 

src/components/ds18x20/controller.h

@@ -41,6 +41,7 @@ class DS18X20Controller {
 private:
   DS18X20Model *_DS18X20_model; ///< ds18x20 model
   std::vector<std::unique_ptr<DS18X20Hardware>> _DS18X20_pins;
+  int _num_drivers;
 };
 extern Wippersnapper_V2 WsV2; ///< Wippersnapper V2 instance
 #endif                        // WS_DS18X20_CONTROLLER_H

src/components/ds18x20/hardware.cpp

@@ -19,14 +19,17 @@
     @brief  DS18X20Hardware constructor
     @param  onewire_pin
             The OneWire bus pin to use.
+    @param  sensor_num
+            Unique identifier for the sensor driver.
 */
 /***********************************************************************/
-DS18X20Hardware::DS18X20Hardware(uint8_t onewire_pin) : _drv_therm(_ow) {
+DS18X20Hardware::DS18X20Hardware(uint8_t onewire_pin, int sensor_num)
+    : _drv_therm(_ow) {
   is_read_temp_c = false;
   is_read_temp_f = false;
+  _sensor_num = sensor_num;
   // Initialize the OneWire bus object
   _onewire_pin = onewire_pin;
-  new (&_ow) OneWireNg_CurrentPlatform(onewire_pin, false);
 }
 
 /***********************************************************************/
@@ -39,13 +42,40 @@ DS18X20Hardware::~DS18X20Hardware() {
           INPUT); // Set the pin to hi-z and release it for other uses
 }
 
-/***********************************************************************/
+/****************************************************************************/
 /*!
-    @brief  Get the sensor's ID
-    @returns True if the sensor was successfully identified, False otherwise.
+    @brief  Initializes the DS18X20 sensor driver and verifies that the
+            sensor is present on the OneWire bus.
+    @returns True if the sensor was successfully initialized, False
+             otherwise.
 */
-/***********************************************************************/
+/****************************************************************************/
 bool DS18X20Hardware::GetSensor() {
+// Initialize the DS18X20 driver
+#ifdef ARDUINO_ARCH_RP2040
+  // RP2040 is special - it uses the PIO's rather than the standard bitbang
+  // implementation In this implementation, we select the PIO instance based on
+  // driver identifier
+
+  // NOTE: We are only going to allow *up to* 7 DS18x20 sensors on RP2040
+  // because the status pixel requires a PIO SM to be allocated prior.
+  int pio_num;
+  if (_sensor_num <= 4) {
+    // drivers 0 thru 3 are handled by PIO0/SM0..4
+    new (&_ow) OneWireNg_CurrentPlatform(_onewire_pin, false, 0);
+  } else if (_sensor_num <= 7) {
+    // drivers 5 thru 8 are handled by PIO1/SM1..4
+    new (&_ow) OneWireNg_CurrentPlatform(_onewire_pin, false, 1);
+  } else {
+    WS_DEBUG_PRINTLN(
+        "[ds18x20] ERROR: You may only add up to 7 sensors on RP2040!");
+    return false;
+  }
+#else
+  // Initialize the standard bit-banged DS18X20 driver object
+  new (&_ow) OneWireNg_CurrentPlatform(_onewire_pin, false);
+#endif
+
   OneWireNg::ErrorCode ec = _ow->readSingleId(_sensorId);
   return ec == OneWireNg::EC_SUCCESS;
 }

src/components/ds18x20/hardware.h

@@ -20,6 +20,12 @@
 #include "drivers/DSTherm.h"
 #include "utils/Placeholder.h"
 
+#if defined(ARDUINO_ARCH_RP2040)
+#define CONFIG_RP2040_PIO_DRIVER ///< Enable the OneWireNg_PicoRP2040PIO driver
+#define CONFIG_RP2040_PIOSM_NUM_USED                                           \
+  1 ///< 4 drivers handled by PIO1, 4 drivers handled by PIO2
+#endif
+
 /**************************************************************************/
 /*!
     @brief  Interface for interacting with the's DallasTemp
@@ -28,7 +34,7 @@
 /**************************************************************************/
 class DS18X20Hardware {
 public:
-  DS18X20Hardware(uint8_t onewire_pin);
+  DS18X20Hardware(uint8_t onewire_pin, int sensor_num);
   ~DS18X20Hardware();
   uint8_t GetOneWirePin();
   void SetResolution(int resolution);
@@ -55,6 +61,7 @@ class DS18X20Hardware {
   uint8_t
       _onewire_pin; ///< Pin utilized by the OneWire bus, used for addressing
   char _onewire_pin_name[5]; ///< Name of the OneWire bus pin
+  int _sensor_num;
   float _period;     ///< The desired period to read the sensor, in seconds
   float _prv_period; ///< Last time the sensor was polled, in seconds
 };