Infineon · ramya-subramanyam · May 6, 2025 · May 2, 2025 · May 2, 2025 · May 2, 2025
diff --git a/ci-build-matrix.json b/ci-build-matrix.json
@@ -8,7 +8,7 @@
     ],
     "example" : [
         "extras/arduino-examples/examples/01.Basics/Blink/Blink.ino",
-        "extras/arduino-examples/examples/03.Analog/AnalogInput/AnalogInput.ino",
+        "extras/arduino-examples/examples/03.Analog/AnalogInOutSerial/AnalogInOutSerial.ino",
         "libraries/SPI/examples/master/master.ino",
         "libraries/SPI/examples/slave/slave.ino",
         "libraries/WiFi/examples/ConnectNoEncryption/ConnectNoEncryption.ino",

diff --git a/cores/psoc6/Arduino.h b/cores/psoc6/Arduino.h
@@ -42,6 +42,8 @@ extern const uint8_t GPIO_PIN_COUNT;
 
 #define GPIO_INTERRUPT_PRIORITY 3 // GPIO interrupt priority
 #define digitalPinToInterrupt(p) ((p) < GPIO_PIN_COUNT ? (p) : -1)
+#define PWM_FREQUENCY_HZ    1000  // 1 kHz
+void analogWriteResolution(int res);
 
 #undef LITTLE_ENDIAN
 

diff --git a/cores/psoc6/analog_io.c b/cores/psoc6/analog_io.c
@@ -1,24 +1,42 @@
 #include "Arduino.h"
 #include "cyhal_adc.h"
+#include "cyhal_pwm.h"
 
 // Constants and Macros
+
 #define MIN_ACQUISITION_TIME        220
 #define adc_assert(cy_ret)          if (cy_ret != CY_RSLT_SUCCESS) { return 0xff; }
+#define pwm_assert(cy_ret)          if (cy_ret != CY_RSLT_SUCCESS) { return; }
+
+#define PWM_RESOLUTION_8_BIT  255.0
+#define PWM_RESOLUTION_10_BIT 1023.0
+#define PWM_RESOLUTION_12_BIT 4095.0
+#define PWM_RESOLUTION_16_BIT 65535.0
 
 // Type Definitions
+
 typedef struct {
     pin_size_t pin;
     cyhal_adc_channel_t chan_obj;
     bool initialized;
 } adc_channel_t;
 
+typedef struct {
+    cyhal_pwm_t pwm_obj;
+    pin_size_t pin;
+    bool initialized;
+} pwm_t;
+
 // Static Variables
+
 static cyhal_adc_t adc_obj = {0};
 static cyhal_adc_vref_t desiredVRef = CYHAL_ADC_REF_VDDA;
 static bool adc_initialized = false;
 static adc_channel_t adc_channel[ADC_HOWMANY] = {0};
+static float desiredWriteResolution = PWM_RESOLUTION_8_BIT;
+static pwm_t pwm[PWM_HOWMANY] = {0};
+
 
-// Helper Function: Initialize ADC hardware if not already done
 static cy_rslt_t initialize_adc(pin_size_t pinNumber) {
     if (!adc_initialized) {
         cy_rslt_t status = cyhal_adc_init(&adc_obj, mapping_gpio_pin[pinNumber], NULL);
@@ -89,3 +107,56 @@ int analogRead(pin_size_t pinNumber) {
 void analogReference(uint8_t mode) {
     desiredVRef = CYHAL_ADC_REF_VDDA;
 }
+
+void analogWriteResolution(int res) {
+    if (res > 12) {
+        desiredWriteResolution = PWM_RESOLUTION_16_BIT;
+    } else if (res > 10) {
+        desiredWriteResolution = PWM_RESOLUTION_12_BIT;
+    } else if (res > 8) {
+        desiredWriteResolution = PWM_RESOLUTION_10_BIT;
+    } else {
+        desiredWriteResolution = PWM_RESOLUTION_8_BIT;
+    }
+}
+
+void analogWrite(pin_size_t pinNumber, int value) {
+    uint8_t pwm_index = 0;
+    cy_rslt_t result = CY_RSLT_TYPE_ERROR;
+
+    if (pinNumber > GPIO_PIN_COUNT) {
+        return; // Invalid pin number
+    }
+
+    // Find existing channel or initialize a new one
+    for (pwm_index = 0; pwm_index < PWM_HOWMANY; pwm_index++) {
+        if (pwm[pwm_index].initialized) {
+            if (pwm[pwm_index].pin == pinNumber) {
+                // Found an existing channel for the pin
+                break;
+            }
+        } else {
+            // Found an uninitialized channel, initialize it
+            result = cyhal_pwm_init(&pwm[pwm_index].pwm_obj, mapping_gpio_pin[pinNumber], NULL);
+            pwm_assert(result);
+            pwm[pwm_index].pin = pinNumber;
+            pwm[pwm_index].initialized = true;
+            break;
+        }
+    }
+
+    if (value < 0) {
+        value = 0;
+    }
+    if (value > desiredWriteResolution) {
+        value = desiredWriteResolution;
+    }
+
+    float duty_cycle_pertentage = (value / desiredWriteResolution) * 100.0f;
+
+    result = cyhal_pwm_set_duty_cycle(&pwm[pwm_index].pwm_obj, duty_cycle_pertentage, PWM_FREQUENCY_HZ);
+    pwm_assert(result);
+
+    result = cyhal_pwm_start(&pwm[pwm_index].pwm_obj);
+    pwm_assert(result);
+}
diff --git a/docs/arduino-deviations.rst b/docs/arduino-deviations.rst
@@ -3,13 +3,14 @@ Arduino API Deviations
 
 This section documents the differences between the standard Arduino Language Reference and `PSoC6-for-Arduino`.
 
-ADC
----
+Analog IO
+---------
 
 Once a pin is configured and used as an ADC input, it may no longer be available for use with any other peripheral (e.g., PWM, I2C, SPI, GPIO, etc.).
 
 The `PSoC6-for-Arduino` core does not support the following Arduino APIs:
 
+
 .. code-block:: cpp
 
     void analogReadResolution(uint8_t bits)
@@ -24,3 +25,24 @@ For applications requiring lower effective resolutions (e.g., 8-bit or 10-bit),
     void analogReference(uint8_t mode)
 
 Only the `DEFAULT` mode is supported and uses the internal reference voltage of the PSoC6 device, which is typically 3.3V.
+
+
+.. code-block:: cpp
+
+    void analogWrite(int pin, int value)
+
+The PWM resolution is fixed at 8 bits by default unless the user explicitly sets a different resolution using the `analogWriteResolution()` function.
+The default frequency of the PWM signal is fixed at **1 kHz** and cannot be changed.
+
+
+.. code-block:: cpp
+
+    void analogWriteResolution(int res)
+
+The input resolution is selected from following fixed options:
+
+- Resolutions greater than 12 bits mapped to **16-bit PWM**.
+- Resolutions greater than 10 bits mapped to **12-bit PWM**.
+- Resolutions greater than 8 bits mapped to **10-bit PWM**.
+- Resolutions of 8 bits or less mapped to **8-bit PWM**.
+
diff --git a/tests/cy8ckit-062s2-ai-hil-test-table.md b/tests/cy8ckit-062s2-ai-hil-test-table.md
@@ -31,7 +31,7 @@
 | SPI           | P9_0          | P9_1           | MOSI and MISO shorted          |
 |               | P9_2          | NC             | SCLK to SCLK                   |
 |               |               |                |                                |
-| ADC           | P10.0         | VDDA 3.3V      | A0 connected to VDDA 3.3V      |
+| Analog IO ADC | P10.0         | VDDA 3.3V      | A0 connected to VDDA 3.3V      |
 |               | P10.1         | VoltageDivider | A1 connected to Voltage        |
 |               |               |                | divider circuit as below:      |
 |               |               |                |                                |
@@ -45,3 +45,6 @@
 |               |               |                |   |                            |
 |               |               |                |  GND (0V)                      |
 |               |               |                |                                |
+| Analog IO PWM | P9.6          | P9.7           | IO6 (PWM feedback) to          |
+|               |               |                |       IO7 (PWM Output)         |
+|               |               |                |                                |
diff --git a/tests/test_config.h b/tests/test_config.h
@@ -13,17 +13,17 @@
 #include <stdint.h>
 
 // Test Pin Definitions
-#define         TEST_DIGITALIO_OUTPUT   7       // IO_4
-#define         TEST_DIGITALIO_INPUT    6       // IO_3
 
-#define         TEST_SYNC_INPUT_OUTPUT  4       // IO_1
+#define         TEST_PIN_DIGITAL_IO_OUTPUT   7      // IO_4
+#define         TEST_PIN_DIGITAL_IO_INPUT    6      // IO_3
 
-#define         TEST_SPI_SLAVE_SELECT   3       // IO_0
+#define         TEST_PIN_SYNC_IO    4               // IO_1
 
-#define         TEST_ANALOG_IO_VREF     A0      // Pin connected to VREF
-#define         TEST_ANALOG_IO_DIVIDER  A1      // Pin connected to voltage divider
+#define         TEST_PIN_SPI_SSEL   3               // IO_0
 
-#define         VDDA                    3.3f    // Assume VDDA is 3.3V
-#define         RESOLUTION              2048    // 11-bit resolution
+#define         TEST_PIN_ANALOG_IO_VREF     A0      // Pin connected to VREF
+#define         TEST_PIN_ANALOG_IO_DIVIDER  A1      // Pin connected to voltage divider
+
+#define         TEST_ADC_RESOLUTION         2048    // 11-bit resolution
 
 #endif // TEST_CONFIG_H
diff --git a/variants/CY8CKIT-062S2-AI/pins_arduino.h b/variants/CY8CKIT-062S2-AI/pins_arduino.h
@@ -63,6 +63,8 @@ static const uint8_t SCK = PIN_SPI_SCK;
 static const uint8_t A0  = PIN_A0;
 static const uint8_t A1  = PIN_A1;
 
+#define PWM_HOWMANY             14 // Number of output pins that can be PWM channels
+
 #define LED1                    12 // Additional LED1
 #define LED_BUILTIN             LED1 // Standard Arduino LED: Uses LED1
 #define LED2                    13 // Additional LED2
@@ -79,19 +81,19 @@ extern "C" {
 
 // Mapping of digital pins and comments
 const cyhal_gpio_t mapping_gpio_pin[] = {
-    /* 0   */ P9_0, // SPI-MOSI         
-    /* 1   */ P9_1, // SPI-MISO        
-    /* 2   */ P9_2, // SPI-SCLK        
-    /* 3   */ P9_3, // IO_0            
-    /* 4   */ P9_4, // IO_1            
-    /* 5   */ P9_5, // IO_2 / PWM1     
-    /* 6   */ P9_6, // IO_3 / PWM2     
-    /* 7   */ P9_7, // IO_4            
+    /* 0   */ P9_0, // SPI-MOSI / PWM         
+    /* 1   */ P9_1, // SPI-MISO / PWM        
+    /* 2   */ P9_2, // SPI-SCLK / PWM        
+    /* 3   */ P9_3, // IO_0 / PWM            
+    /* 4   */ P9_4, // IO_1 / PWM            
+    /* 5   */ P9_5, // IO_2 / PWM     
+    /* 6   */ P9_6, // IO_3 / PWM     
+    /* 7   */ P9_7, // IO_4 / PWM            
 
-    /* 8   */ P0_2, // I2C-SCL         
-    /* 9   */ P0_3, // I2C-SDA         
-    /* 10  */ P10_1,// A1 / UART_TX    
-    /* 11  */ P10_0,// A0 / UART_RX    
+    /* 8   */ P0_2, // I2C-SCL / PWM         
+    /* 9   */ P0_3, // I2C-SDA / PWM         
+    /* 10  */ P10_1,// A1 / UART_TX / PWM    
+    /* 11  */ P10_0,// A0 / UART_RX / PWM    
 
     // on board LEDs and USER BUTTON
 
@@ -101,22 +103,22 @@ const cyhal_gpio_t mapping_gpio_pin[] = {
 
     // Additional pins for expansion IO connector - J15 starting here
 
-    /* 15  */ P13_0,// SDHC_DATA00 / SPI-MOSI / UART_RX / I2C-SCL     
-    /* 16  */ P13_1,// SDHC_DATA01 / SPI-MISO / UART_TX / I2C-SDA     
+    /* 15  */ P13_0,// SDHC_DATA00 / SPI-MOSI / UART_RX / I2C-SCL / PWM     
+    /* 16  */ P13_1,// SDHC_DATA01 / SPI-MISO / UART_TX / I2C-SDA / PWM     
     /* 17  */ P13_2,// SDHC_DATA02 / SPI-SCLK / IO / PWM             
     /* 18  */ P13_3,// SDHC_DATA03 / IO / PWM                         
-    /* 19  */ P13_4,// SDHC_DATA10 / UART_RX / I2C-SCL                
-    /* 20  */ P13_5,// SDHC_DATA11 / UART_TX / I2C-SDA                
+    /* 19  */ P13_4,// SDHC_DATA10 / UART_RX / I2C-SCL / PWM                
+    /* 20  */ P13_5,// SDHC_DATA11 / UART_TX / I2C-SDA / PWM                
     /* 21  */ P13_6,// SDHC_DATA12 / IO / PWM                         
     /* 22  */ P13_7,// SDHC_DATA13 / IO / PWM                         
-    /* 23  */ P8_2,// SPI-SCLK / IO /PWM                              
+    /* 23  */ P8_2,// SPI-SCLK / IO / PWM                              
     /* 24  */ P8_1,// SPI-MISO / UART_TX / I2C-SDA / IO / PWM         
     /* 25  */ P8_0,// SPI-MOSI / UART_RX / I2C-SCL / IO / PWM         
     /* 26  */ P8_3,// IO / PWM                                        
-    /* 27  */ P8_4,// UART_RX / I2C-SCL / IO /PWM                     
-    /* 28  */ P8_5,// UART_TX / I2C-SDA / IO /PWM                     
-    /* 29  */ P12_4,// SDHC_CMD / IO /PWM                             
-    /* 30  */ P12_5,// SDHC_CLK / IO /PWM
+    /* 27  */ P8_4,// UART_RX / I2C-SCL / IO / PWM                     
+    /* 28  */ P8_5,// UART_TX / I2C-SDA / IO / PWM                     
+    /* 29  */ P12_4,// SDHC_CMD / IO / PWM                             
+    /* 30  */ P12_5,// SDHC_CLK / IO / PWM
 
     // Debugger Serial UART pins (not available on connector)