Documentation: Write some docu

* Safety notice
* HW modifications
* Links to PCB repo

doc/source/firmware/pt1000-processing.rst

@@ -62,6 +62,8 @@ The filter then removes the two most extreme values and computes the average of
 Therefore, by default, the resulting datastream has a sampling rate of 1/6 kHz. This depends on the :c:macro:`ADC_PT1000_SAMPLE_CNT_DELAY` and ``n``
 
 
+.. _firmware_meas_adc_watchdog:
+
 Watchdog
 ~~~~~~~~
 

doc/source/hardware/frontend.rst

@@ -8,5 +8,3 @@ Schematic
 
 .. image:: frontend-schematic_v1.2.svg
    :target: /_images/frontend-schematic_v1.2.svg
-
-

doc/source/hardware/index.rst

@@ -10,3 +10,11 @@ This guide on the reflow controller's hardware is based on the ``reflow-oven-con
 	:glob:
 
 	*
+
+Links
+-----
+
+- `Reflow Oven Control PCB v1.2 schematic <https://git.shimatta.de/attachments/788fde4e-a560-445b-87ea-de1d67f6846a>`__
+- `Git Repository for Controller PCB <https://git.shimatta.de/pcb/reflow-oven-control-pcb>`__
+
+

doc/source/hardware/modifications.rst

@@ -0,0 +1,15 @@
+.. _hardware_modifications:
+
+Hardware Modifications
+======================
+
+Analog Frontend
+---------------
+
+.. note::
+	Solder a ``100 nF`` capacitor parallel to ``R315`` in order to implement a low pass characteristic of the difference amplifier in the :ref:`analog frontend<hw_analog_fe>`. This massively increases EMI performance which prevents the :ref:`ADC Watchdog<firmware_meas_adc_watchdog>` from triggering.
+
+Power Supply
+------------
+.. note::
+	Replace transformer ``BV-EI-303-2010`` with ``BV-EI-303-2050``, which has the same footprint but a little more power and does not heat that much.

doc/source/index.rst

@@ -10,6 +10,10 @@ Quick Links
 ===========
 
 * :ref:`genindex`
+* :ref:`hardware_modifications`
+
+.. warning::
+	Although the Shimatta Reflow Controller provides a bunch of safety mechanisms that prevent your house from burning down, NEVER leave the oven controller running unattended.
 
 .. toctree::
 	:maxdepth: 2