clawdmeter/README.md

Claude Usage Tracker - Panlee SC01 Plus

Bluetooth-connected Claude Code usage monitor and touch controller on a Panlee SC01 Plus (ESP32-S3) 3.5" touchscreen.

Features

• Usage dashboard — Live 5-hour session and 7-day weekly utilization bars with color-coded thresholds
• Touch controller — Gesture-based Claude Code navigation (swipe, tap, hold) sent as BLE HID keyboard input
• Bluetooth screen — Connection status, device name, MAC address, bond management
• Wireless — All communication over Bluetooth Low Energy (USB only for charging and flashing)
• Auto-reconnect — Daemon discovers and reconnects automatically with exponential backoff

Hardware

• Panlee SC01 Plus (WT32-SC01 Plus) — ESP32-S3, 3.5" 480x320 IPS, capacitive touch
• USB-C cable for flashing firmware and charging

Prerequisites

• Linux (tested on Ubuntu)
• PlatformIO CLI
• curl, bluetoothctl, busctl (BlueZ Bluetooth stack)
• Claude Code with an active subscription

Flash the firmware

cd firmware
pio run -t upload --upload-port /dev/ttyACM0

Bluetooth pairing

After flashing, the device advertises as "Claude Controller". Pair it once:

# Scan for the device
bluetoothctl scan le

# When "Claude Controller" appears, pair and trust it
bluetoothctl pair F4:12:FA:C0:8F:E5    # use your device's MAC
bluetoothctl trust F4:12:FA:C0:8F:E5

The MAC address is shown on the Bluetooth screen (third screen, tap the logo to cycle).

Install the daemon

The daemon polls your Claude usage every 30 seconds and sends it to the display over BLE.

./install.sh
systemctl --user start claude-usage-daemon

Check status: systemctl --user status claude-usage-daemon

View logs: journalctl --user -u claude-usage-daemon -f

How it works

1. The daemon reads your Claude Code OAuth token from ~/.claude/.credentials.json
2. Makes a minimal API call to api.anthropic.com/v1/messages (1 token of Haiku, essentially free)
3. Extracts usage data from the response headers (anthropic-ratelimit-unified-5h-utilization, etc.)
4. Connects to the ESP32 over BLE and writes a JSON payload to the GATT RX characteristic
5. The ESP32 parses it and updates the LVGL dashboard
6. Touch gestures on the Controller screen are sent as BLE HID keyboard input to the host

Screens

Tap the Claude logo (top-left) to cycle between screens:

Usage	Controller	Bluetooth
Session and weekly utilization	Touch zones and swipe gestures	Connection status and reset

Gesture controls

On the Controller screen:

Gesture	Action
Swipe up	Arrow Up
Swipe down	Arrow Down
Swipe left	Shift+Tab (toggle mode)
Swipe right	Enter
Hold (center)	Space (voice dictation)

Touch zones (tap):

Zone	Action
Top-left	Escape
Bottom-left	Arrow Left
Top-right	Delete
Bottom-right	Arrow Right

BLE protocol

The device advertises a custom GATT service alongside the standard HID keyboard service:

	UUID
Data Service	4c41555a-4465-7669-6365-000000000001
RX Characteristic (write)	4c41555a-4465-7669-6365-000000000002
TX Characteristic (notify)	4c41555a-4465-7669-6365-000000000003
HID Service	00001812-0000-1000-8000-00805f9b34fb

JSON payload format (written to RX):

{ "s": 45, "sr": 120, "w": 28, "wr": 7200, "st": "allowed", "ok": true }

Fields: s = session %, sr = session reset (minutes), w = weekly %, wr = weekly reset (minutes), st = status, ok = success flag.

Recompiling fonts

The firmware/src/font_*.c files are pre-compiled LVGL bitmap fonts. If you need to regenerate them (e.g. to change sizes or add characters):

npm install -g lv_font_conv

Generate with --no-compress (required for LVGL 9):

# Tiempos Text (title)
lv_font_conv --font assets/TiemposText-400-Regular.otf -r 0x20-0x7E \
  --size 34 --format lvgl --bpp 4 --no-compress \
  -o firmware/src/font_tiempos_34.c --lv-include "lvgl.h"

# Styrene B (UI text)
lv_font_conv --font assets/StyreneB-Regular.otf -r 0x20-0x7E \
  --size 28 --format lvgl --bpp 4 --no-compress \
  -o firmware/src/font_styrene_28.c --lv-include "lvgl.h"

# DejaVu Sans Mono (animation, with spinner Unicode chars)
lv_font_conv --font assets/DejaVuSansMono.ttf \
  -r 0x20-0x7E,0xB7,0x2026,0x2722,0x2733,0x2736,0x273B,0x273D \
  --size 18 --format lvgl --bpp 4 --no-compress \
  -o firmware/src/font_mono_18.c --lv-include "lvgl.h"

Important: lv_font_conv v1.5.3 outputs LVGL 8 format. Each generated file must be patched for LVGL 9 compatibility:

1. Remove #if LVGL_VERSION_MAJOR >= 8 guards around font_dsc and the font struct
2. Remove the .cache field from font_dsc
3. Add .release_glyph = NULL, .kerning = 0, .static_bitmap = 0 to the font struct
4. Add .fallback = NULL, .user_data = NULL to the font struct

Without these patches, fonts compile but render as invisible.

Converting Lucide icons

The controller screen uses Lucide icons (the same icon set Anthropic uses). Icons are SVGs converted to RGB565 C arrays for LVGL.

1. Get Lucide SVGs from github.com/lucide-icons/lucide (icons/ directory)

2. Convert SVG to PNG at desired size:

inkscape icons/delete.svg --export-width=32 --export-height=32 \
  --export-filename=assets/icon_delete.png --export-background-opacity=0

3. Convert PNG to RGB565 C array:

from PIL import Image

img = Image.open("assets/icon_delete.png").convert("RGBA")
bg = (0x1f, 0x1f, 0x1e)  # panel background color
fg = (0xb0, 0xae, 0xa5)  # icon stroke color

pixels = []
for y in range(img.height):
    for x in range(img.width):
        r, g, b, a = img.getpixel((x, y))
        alpha = a / 255.0
        out_r = int(fg[0] * alpha + bg[0] * (1 - alpha))
        out_g = int(fg[1] * alpha + bg[1] * (1 - alpha))
        out_b = int(fg[2] * alpha + bg[2] * (1 - alpha))
        rgb565 = ((out_r >> 3) << 11) | ((out_g >> 2) << 5) | (out_b >> 3)
        pixels.append(rgb565)

# Write as C array to firmware/src/icons.h

Current icons: delete, arrow-left, arrow-right, circle-arrow-out-up-left (escape), hand (gestures), bluetooth.

Licensing gray area warning

The software in this repository uses and adheres to the Anthropic brand guidelines and uses the same proprietary fonts that Anthropic has a licnese for but this software uses without permission as well as using assets from Anthropic such as the copyrighted Claude Code mascot head logo so even though the code in this repo is non-proprietary I will not license it myself under a copyleft license since this repo includes proprietary fonts and copyrighted assets. Please be aware of this if you fork or copy the code from this repo. You have been warned!