Implement analogRead() API which allows to read the value provided at any of the analog pins of the ESP32.

Author: aentinger

src/utility/wifi_drv.cpp

@@ -1119,9 +1119,32 @@ void WiFiDrv::digitalWrite(uint8_t pin, uint8_t value)
     SpiDrv::spiSlaveDeselect();
 }
 
-int WiFiDrv::analogRead(uint8_t pin)
+uint16_t WiFiDrv::analogRead(uint8_t pin)
 {
-#warning "This needs to be implemented!!!"
+    WAIT_FOR_SLAVE_SELECT();
+    // Send Command
+    SpiDrv::sendCmd(GET_ANALOG_READ, PARAM_NUMS_1);
+    SpiDrv::sendParam((uint8_t*)&pin, 1, LAST_PARAM);
+
+    // pad to multiple of 4
+    SpiDrv::readChar();
+    SpiDrv::readChar();
+
+    SpiDrv::spiSlaveDeselect();
+    //Wait the reply elaboration
+    SpiDrv::waitForSlaveReady();
+    SpiDrv::spiSlaveSelect();
+
+    // Wait for reply
+    uint16_t adc_raw = 0;
+    uint8_t adc_raw_len = 0;
+    if (!SpiDrv::waitResponseCmd(GET_ANALOG_READ, PARAM_NUMS_1, (uint8_t*)&adc_raw, &adc_raw_len))
+    {
+        WARN("error waitResponse");
+    }
+    SpiDrv::spiSlaveDeselect();
+
+    return adc_raw;
 }
 
 void WiFiDrv::analogWrite(uint8_t pin, uint8_t value)

src/utility/wifi_drv.h

@@ -292,7 +292,7 @@ class WiFiDrv
     static void pinMode(uint8_t pin, uint8_t mode);
     static PinStatus digitalRead(uint8_t pin);
     static void digitalWrite(uint8_t pin, uint8_t value);
-    static int analogRead(uint8_t pin);
+    static uint16_t analogRead(uint8_t pin);
     static void analogWrite(uint8_t pin, uint8_t value);
 
     static int8_t downloadFile(const char* url, uint8_t url_len, const char *filename, uint8_t filename_len);

src/utility/wifi_spi.h

@@ -103,6 +103,7 @@ enum {
     SET_DIGITAL_WRITE	= 0x51,
     SET_ANALOG_WRITE	= 0x52,
     GET_DIGITAL_READ    = 0x53,
+	GET_ANALOG_READ     = 0x54,
 
     // regular format commands
     WRITE_FILE			= 0x60,