I got a little automata tikzpicture but the more complex it got, the less readable it became. So I wanted to adjust the font size of the edge labels but I just can't figure out how to do that. Tried looking in the tikzpgf manual and also on here but I only find `scale` and `fontsize` for the nodes but not for the edge labels in the path commands.

For example I want to make the text in these two paths here smaller:

```
\usepackage{pgfplots}
\usetikzlibrary{automata,positioning,fit,shapes.geometric,backgrounds}

\begin{figure}
\begin{tikzpicture}[node distance=1.5cm]
\node  [state, initial] (Neutral)       {Neutral};   
\node[state]
    (UI Popup)
    [right=of Neutral]
    {Popped UI};

\node[state]
    (Sine)
    [above right=of UI Popup]
    [fill=gray]
    {\includegraphics[width=1.8cm]{sinecurve2}};

\node[state, circle split]
    (Digital_Off)
    [scale=0.75]
    [below right=of UI Popup]
    {Digital [Off] \nodepart{lower} \includegraphics[width=0.5cm]{pin_off}};

\node[state, circle split]
    (Digital_On)
    [scale=0.75]
    [right=of Digital_Off]
    {Digital [On] \nodepart{lower} \includegraphics[width=0.5cm]{pin_on}};

    \begin{scope}[on background layer]
\node[fit=(Digital_Off) (Digital_On), rectangle, rounded corners, draw=red, label=above:Digital state] (digital) {};
\end{scope}

\path[->] [line width=0.3mm]
            (Neutral)       edge [scale=0.2] node [above]      {Tap}                    (UI Popup)
            (UI Popup)      edge [bend left] node [above left]  {Tap and select analog} (Sine)
                            edge [bend right] node [below left] {Tap and select digital}    (Digital_Off)
            (Digital_Off)   edge [bend left] node [above]      {Tap}                    (Digital_On)
            (Digital_On)    edge [bend left] node [below]      {Tap}                    (Digital_Off)
            %(digital)      edge [bend left] node [above]      {Tap}                    (Sine)    
            (digital)       edge [bend right] node [above]     {Long click}             (UI Popup)
            (Sine)          edge [bend left]  node [below]     {Long click}             (UI Popup)
                        ;                    
\end{tikzpicture}
\caption{Input pin behavior}
\end{figure}

```

**Edit:**

This tikzpicture is in a separate file which begins with \chapter{...} and the main.tex file looks like this:

```
%!TEX root = ./main.tex

\documentclass[11pt, a4paper, titlepage]{book}
\include{i10preamble}
\begin{document}
\sloppy
\include{indexAddOn}

\frontmatter

\begin{titlepage}
\AddToShipoutPicture*{
\put(0,0){
\includegraphics[width=\paperwidth]{titlepage_Master_CID}}}
\strut
\end{titlepage}

% Lots of other stuff inside

\end{document}

```

[![enter image description here](https://i.stack.imgur.com/pAZZV.png)](https://i.stack.imgur.com/pAZZV.png)