diff --git a/docs/Doxyfile b/docs/Doxyfile
index 1262877d..4c503d3b 100644
--- a/docs/Doxyfile
+++ b/docs/Doxyfile
@@ -52,7 +52,10 @@ INPUT = \
     ../../components/esp8266/include/driver/gpio.h \
     ../../components/esp8266/include/driver/i2c.h \
     ../../components/esp8266/include/driver/pwm.h \
-    ../../components/esp8266/include/driver/uart.h
+    ../../components/esp8266/include/driver/uart.h \
+    ../../components/esp8266/include/driver/adc.h \
+    ../../components/esp8266/include/driver/spi.h \
+    ../../components/esp8266/include/driver/hw_timer.h
     ##
 
 ## Get warnings for functions that have no documentation for their parameters or return value
diff --git a/docs/en/api-guides/index.rst b/docs/en/api-guides/index.rst
index 332d9502..a65df392 100644
--- a/docs/en/api-guides/index.rst
+++ b/docs/en/api-guides/index.rst
@@ -6,3 +6,6 @@ API Guides
 
    Build System <build-system>
    Partition Tables <partition-tables>
+   System Task <system-tasks>
+   PWM and Sniffer Coexists <pwm-and-sniffer-coexists>
+   FOTA from an Old SDK to the New ESP8266 RTOS SDK (IDF Style) <fota-from-old-new>
diff --git a/docs/en/api-reference/peripherals/adc.rst b/docs/en/api-reference/peripherals/adc.rst
new file mode 100644
index 00000000..3f69faec
--- /dev/null
+++ b/docs/en/api-reference/peripherals/adc.rst
@@ -0,0 +1,7 @@
+ADC
+===
+
+API Reference
+-------------
+
+.. include:: /_build/inc/adc.inc
\ No newline at end of file
diff --git a/docs/en/api-reference/peripherals/hw_timer.rst b/docs/en/api-reference/peripherals/hw_timer.rst
new file mode 100644
index 00000000..50f2a9ec
--- /dev/null
+++ b/docs/en/api-reference/peripherals/hw_timer.rst
@@ -0,0 +1,7 @@
+Hardware Timer
+==============
+
+API Reference
+-------------
+
+.. include:: /_build/inc/hw_timer.inc
\ No newline at end of file
diff --git a/docs/en/api-reference/peripherals/index.rst b/docs/en/api-reference/peripherals/index.rst
index 7b5d157f..0c75709a 100644
--- a/docs/en/api-reference/peripherals/index.rst
+++ b/docs/en/api-reference/peripherals/index.rst
@@ -6,8 +6,11 @@ Peripherals API
 
    GPIO <gpio>
    I2C <i2c>
+   SPI <spi>
    PWM <pwm>
    UART <uart>
+   ADC <adc>
+   Hardware Timer <hw_timer>
 
 Example code for this API section is provided in :example:`peripherals` directory of ESP-IDF examples.
 
diff --git a/docs/en/api-reference/peripherals/spi.rst b/docs/en/api-reference/peripherals/spi.rst
new file mode 100644
index 00000000..23519a9b
--- /dev/null
+++ b/docs/en/api-reference/peripherals/spi.rst
@@ -0,0 +1,7 @@
+SPI
+===
+
+API Reference
+-------------
+
+.. include:: /_build/inc/spi.inc
\ No newline at end of file