clawdmeter/README.md

Claude Usage Tracker - Waveshare ESP32-S3-Touch-AMOLED-2.16

Bluetooth-connected Claude Code usage monitor on a Waveshare ESP32-S3-Touch-AMOLED-2.16 2.16" square AMOLED with battery, IMU-driven auto-rotation, two physical buttons mapped to Claude Code shortcuts over BLE HID, and a splash screen of pixel-art creatures whose mood tracks your usage rate.

Screens

Two persistent screens, Usage and Bluetooth, are cycled by the middle physical button (PWR). The splash is a touch-toggled welcome animation: tap anywhere on the display (outside the Reset zone on the Bluetooth screen) to show it; tap again to dismiss. Splash is the default boot screen.

Splash	Usage	Bluetooth
Boot screen; touch-toggle anytime	Session and weekly utilization	Connection status and bond reset

On splash, the middle (PWR) button cycles to the next animation manually; otherwise the firmware auto-rotates every 20 s within the usage-rate group.

Features

• Splash screen — 13 looping 20×20 pixel-art creature animations scaled 24× to fill the display. The active animation reacts to your current Claude usage rate (idle / normal / active / heavy), auto-rotating within the matching group every 20 s.
• Usage dashboard — Live 5-hour session and 7-day weekly utilization bars with reset countdowns.
• Physical button shortcuts — Left button → Space (voice mode), right button → Shift+Tab (mode toggle); both sent over BLE HID.
• Bluetooth screen — Connection status, device name, MAC address, bond reset zone.
• Auto-rotation — QMI8658 accelerometer drives 90° rotation snaps with a quick AMOLED brightness-flash transition.
• Battery indicator — Lucide battery icons in the upper-right corner, AXP2101-driven.
• Wireless — All data communication over Bluetooth Low Energy (USB only for flashing and charging).

Hardware

• Waveshare ESP32-S3-Touch-AMOLED-2.16 — ESP32-S3R8, 2.16" 480×480 AMOLED (CO5300 QSPI), CST9220 cap touch, AXP2101 PMU + Li-Po battery, QMI8658 IMU
• USB-C cable for flashing firmware and charging
• 3.7V Li-Po battery (MX1.25 2-pin connector, optional)

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 — press the middle (PWR) button to cycle to it.

Install the daemon

The daemon polls your Claude usage every 60 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. The firmware tracks the rate of change of session % over a 5-minute window and picks splash animations from the matching mood group (idle / normal / active / heavy)
7. The left/right physical buttons send Space and Shift+Tab as BLE HID keyboard input to the paired host (no host-side daemon involvement)

Physical buttons

The board has three physical buttons in a row. Functions are global (screen-independent) for the left and right buttons; the middle button is screen-aware.

Button	GPIO	Function
Left	GPIO 0	Hold to send Space (Claude Code voice-mode push-to-talk)
Middle (PWR)	AXP2101 PKEY	Cycle screens (Usage ↔ Bluetooth); on splash, cycle animations
Right	GPIO 18	Press to send Shift+Tab (Claude Code mode toggle)

Space and Shift+Tab are delivered as standard BLE HID keyboard reports — they work in any focused window on the paired host, not just Claude Code.

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. Sizes are scaled for the 314 PPI 2.16" display (~1.9× the original 165 PPI 3.5" panel).

npm install -g lv_font_conv

Generate each one (one at a time — lv_font_conv doesn't like loop-driven invocations) with --no-compress (required for LVGL 9):

# Tiempos Text (titles, 56px)
lv_font_conv --font assets/TiemposText-400-Regular.otf -r 0x20-0x7E \
  --size 56 --format lvgl --bpp 4 --no-compress \
  -o firmware/src/font_tiempos_56.c --lv-include "lvgl.h"

# Styrene B (large numbers 48, panel labels 28, small text 24, minimal 20)
for size in 48 28 24 20; do
  lv_font_conv --font assets/StyreneB-Regular.otf -r 0x20-0x7E \
    --size $size --format lvgl --bpp 4 --no-compress \
    -o firmware/src/font_styrene_${size}.c --lv-include "lvgl.h"
done

# DejaVu Sans Mono (32px, with spinner Unicode chars)
lv_font_conv --font assets/DejaVuSansMono.ttf \
  -r 0x20-0x7E,0xB7,0x2026,0x2722,0x2733,0x2736,0x273B,0x273D \
  --size 32 --format lvgl --bpp 4 --no-compress \
  -o firmware/src/font_mono_32.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 UI uses a small set of Lucide icons (bluetooth + battery states) converted to RGB565 / RGB565A8 C arrays for LVGL.

node tools/png_to_lvgl.js assets/icon_bluetooth_48.png icon_bluetooth_data ICON_BLUETOOTH_WIDTH ICON_BLUETOOTH_HEIGHT

Default tint is white (0xFFFFFF), required because Lucide PNGs ship as black-on-transparent and would render invisible against the dark UI without it. Pass --no-tint for pre-coloured artwork (e.g. the logo). Battery icons live as RGB565A8 (alpha plane) so they blend cleanly over the splash background; the rest of the icons are baked RGB565 over the panel colour. Splice the converter output into firmware/src/icons.h.

Splash animations

The splash screen plays 20×20 pixel-art creature animations sourced from claudepix.vercel.app, a public library of creature animations. Frame data and palettes are extracted by tools/scrape_claudepix.js (which evaluates the source's JavaScript in a Node VM context to resolve frames) and converted to RGB565 C arrays by tools/convert_to_c.js. The output lives in firmware/src/splash_animations.h.

To re-pull (e.g. when the source library updates):

node tools/scrape_claudepix.js
node tools/convert_to_c.js
pio run -d firmware -t upload

See tools/README.md for details.

Credits

• Built by @hermannbjorgvin (Hermann Björgvin Haraldsson).
• Pixel-art Clawd animation by @amaanbuilds, sourced from claudepix.vercel.app. Frame data and palettes scraped + converted by the tooling in tools/.
• Lucide icon set (lucide.dev, MIT) for bluetooth and battery UI glyphs.
• Anthropic brand fonts (Tiempos Text, Styrene B) — see licensing warning below.

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 Clawd mascot 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!