Updated tools scripts, resize preview images to be smaller.

_posts/2023-08-06-HP-8560A-spectrum-analyzer-as-a-frequency-generator.md

@@ -4,7 +4,7 @@ author: peter
 date: 2023-08-06 21:45:13 +0800
 categories: [Electronics] # Blogging | Electronics | Programming | Mechanical
 tags: [electronics, rf, oscilloscope, spectrum analyzer, hack] # systems | embedded | rf | microwave | electronics | solidworks | automation
-image: /assets/img/2023-08-06-HP-8560A-spectrum/IMG20230801205713.jpg
+image: /assets/img/2023-08-06-HP-8560A-spectrum/preview.png
 ---
 
 I just bought a Hitachi VC-6025 oscilloscope from my Singapore trip for 85 SGD. It's a good deal, since there is not a lot of second-hand electronics auctions on Ebay Australia, and the shipping costs from overseas or even interstate make it not very economical.

_posts/2023-08-09-Aliexpress-DC-block-characterization.md

@@ -4,7 +4,7 @@ author: peter
 date: 2023-08-09 19:41:27 +0800
 categories: [Electronics] # Blogging | Electronics | Programming | Mechanical
 tags: [rf, microwave, electronics] # systems | embedded | rf | microwave | electronics | solidworks | automation
-image: /assets/img/2023-08-09-Aliexpress-DC-block/IMG20230809200758.jpg
+image: /assets/img/2023-08-09-Aliexpress-DC-block/preview.png
 ---
 
 I recently purchased [this DC block](https://www.aliexpress.com/item/1005002575850555.html) from Aliexpress to protect our HP 8560A spectrum analyzer. I did some basic tests on the DC block and it looks good for the price. These N type DC blocks seem to be less common and twice as expensive than the SMA type, but I wanted to avoid using SMA hardware for my setup.

_posts/2024-02-15-Altium-to-3d-GLTF.md

@@ -4,7 +4,7 @@ author: peter
 date: 2024-02-15 16:41:46 +0800
 categories: [Blogging, Electronics] # Blogging | Electronics | Programming | Mechanical
 tags: [electronics, solidworks] # systems | embedded | rf | microwave | electronics | solidworks | automation
-image: /assets/img/2024-02-15-Altium-to-3d-GLTF/website.png
+image: /assets/img/2024-02-15-Altium-to-3d-GLTF/preview.png
 ---
 
 As part of the [Neptunium flight computer](https://www.petertanner.dev/neptunium/), I wanted to create a proper webpage to showcase the flight computer. This will also be a landing page for people who want to use the wasm powered Neptunium Explorer, which will allow users to analyze flight data in the browser. At the center of this webpage I want to show an interactive 3d model of the flight computer

_posts/2024-02-24-Inside-a-bus-USB-charger.md

@@ -4,7 +4,7 @@ author: peter
 date: 2024-02-24 14:06:00 +0800
 categories: [Electronics] # Blogging | Electronics | Programming | Mechanical
 tags: [electronics, bus] # systems | embedded | rf | microwave | electronics | solidworks | automation
-image: /assets/img/2024-02-24-Inside-a-bus-USB-cha/usb-charger-bus-highres.jpg
+image: /assets/img/2024-02-24-Inside-a-bus-USB-cha/preview.png
 ---
 
 Random post, on the bus I saw one of those wall-mounted USB chargers with the plastic cover already removed (I did not remove it). This is what the PCB inside of it looks like.

generate-preview-images.sh

@@ -0,0 +1,44 @@
+#!/bin/bash
+
+# Function to convert JPG/JPEG to PNG
+convert_to_png() {
+    local file="$1"
+    local filename="${file%.*}"  # Remove extension
+    local new_file="${filename}.png"
+
+    echo "Converting $file to PNG..."
+    convert "$file" "$new_file"
+    echo "Converted $file to PNG: $new_file"
+
+    # Update file variable to the new PNG file
+    file="$new_file"
+}
+
+# Loop through all preview.jpg and preview.jpeg files in assets/img/<folder> directories
+for file in assets/img/*/{preview.jpg,preview.jpeg}; do
+    if [ -f "$file" ]; then
+        # Convert JPG/JPEG to PNG
+        convert_to_png "$file"
+    fi
+done
+
+
+# Loop through all preview.png files in assets/img/<folder> directories
+for file in assets/img/*/preview.png; do
+    if [ -f "$file" ]; then
+        # Get current dimensions
+        current_width=$(identify -format "%w" "$file")
+        current_height=$(identify -format "%h" "$file")
+
+        # Calculate new dimensions, keeping aspect ratio
+        new_width=1200
+        new_height=630
+        if [ "$current_width" -gt "$new_width" ] || [ "$current_height" -gt "$new_height" ]; then
+            # Resize only if current dimensions exceed the new dimensions
+            convert "$file" -resize "${new_width}x${new_height}>" "$file"
+            echo "Resized $file"
+        # else
+            # echo "No need to resize $file"
+        fi
+    fi
+done

post.sh

@@ -7,18 +7,6 @@ sanitize_title() {
     echo "$sanitized_title" | tr ' ' '-'
 }
 
-# Function to generate the front matter with the current date
-generate_front_matter() {
-    current_date=$(date +'%Y-%m-%d %H:%M:%S %z')
-    echo "---"
-    echo "title: $1"
-    echo "author: peter"
-    echo "date: $current_date"
-    echo "categories: [Blogging]    # Blogging | Electronics | Programming | Mechanical"
-    echo "tags: [getting started]   # systems | embedded | rf | microwave | electronics | solidworks | automation"
-    echo "---"
-}
-
 # Prompt the user for a title
 read -e -p "Enter the title: " user_title
 
@@ -30,6 +18,19 @@ current_date=$(date +'%Y-%m-%d')
 filename="${current_date}-${sanitized_title}"
 filepath="_posts/${filename}.md"
 
+# Function to generate the front matter with the current date
+generate_front_matter() {
+    current_date=$(date +'%Y-%m-%d %H:%M:%S %z')
+    echo "---"
+    echo "title: $1"
+    echo "author: peter"
+    echo "date: $current_date"
+    echo "categories: [Blogging]    # Blogging | Electronics | Programming | Mechanical"
+    echo "tags: [getting started]   # systems | embedded | rf | microwave | electronics | solidworks | automation"
+    echo "# image: assets/img/${filename:0:31}/preview.png"
+    echo "---"
+}
+
 # Check if the file already exists
 if [ -e "$filepath" ]; then
     echo "A file with the name '$filename' already exists in the '_posts' subdirectory."

push.sh

@@ -15,6 +15,9 @@ new_posts="$(get_new_posts)"
 
 # Check if there are any new or modified files to commit
 if [ -n "$new_posts" ]; then
+
+    ./generate-preview-images.sh
+
     # Add all new and modified files
     echo "$commit_msg"
     git add $new_posts