TigerScale
Purpose
Section titled “Purpose”TigerScale answers the eternal question: how much filament is left? Put a spool on the open-source ESP32 scale and the live weight flows straight into your inventory — no manual entry, no shaking the spool next to your ear.
The chip knows what the filament is; the scale knows how much is left. Together they make the inventory actually true: identity from TigerTag, live quantity from TigerScale.
Where it sits
Section titled “Where it sits”
flowchart LR
SPOOL["Spool on the scale"] --> SCALE["TigerScale (ESP32)"]
SCALE -- "live weight" --> CLOUD[("Your TigerSystem account<br/>(Firebase)")]
CLOUD --> ST["Tiger Studio"] & CO["Connect"]
Two generations
Section titled “Two generations”TigerScale V3 — the current generation (Tiger-Scale-V3, MIT):
- It knows which spool is on it: dual PN532 NFC readers, one per side — a twin-tagged spool is identified whichever way you put it down. Read the tag, weigh, subtract the empty spool’s weight, sync — no typing, no guessing.
- ESP32-S3 (16 MB flash, PSRAM), 3.5″ 480×320 colour touchscreen (LVGL) with full on-screen setup: WiFi picker + keyboard, calibration wizard, hardware self-test, OTA updates.
- Battery powered (AXP2101 PMIC, charge state on screen), audio codec.
- Precision weighing: HX711 + load cell, median + adaptive EMA filtering — tuned for a kitchen-scale feel.
- 8 firmware languages, 9-language web UI.
TigerScale V2 — the previous generation (Tiger-Scale, MIT): ESP32-WROOM, 0.96″ OLED, 2× RC522 readers, USB-powered. V3 is different hardware, not a firmware update — the two are not interchangeable; V2 builders keep using the V2 repository.
Heritage — the V1. A first generation existed but was never released as a public repository. It carried essentially the V2’s electronics — ESP32, mini OLED, an HX711 board with a 5 kg load cell — but a single PN532 reader, in a completely different form factor: a spool-holder design, with a central support passing through the middle of the spool.
Features (both generations)
Section titled “Features (both generations)”- Fully open source (MIT) — commodity parts, the living proof that an ESP32 and an NFC reader module (PN532 / RC522 class) are enough to build a TigerTag-reading device.
- Live weight tracking — updates appear in real time in Tiger Studio and Tiger NFC Connect via Firestore.
- Works with Tiger Studio’s container weight calibration so net filament weight stays accurate per container type.
Third-party scales — USB HID (DYMO M series and friends)
Section titled “Third-party scales — USB HID (DYMO M series and friends)”TigerScale is the first-party scale — but Tiger Studio also reads standard
USB “HID Scale” devices (HID usage page 0x8D, usage 0x20): starting
with the DYMO M5 and the rest of the DYMO M series (M10, M25… same
protocol), and any compliant HID Scale, whatever the brand. A third-party
option, not a Tiger product.
Protocol, validated on real hardware — 6-byte Scale Data Reports at ~1 Hz:
| Byte | Meaning |
|---|---|
[0] |
report id 0x03 |
[1] |
status: 1 fault · 2 stable @ zero · 3 in motion · 4 stable · 5 negative · 6 over capacity |
[2] |
unit (HID PoS codes): 0x02 gram · 0x0B ounce · 0x0C pound |
[3] |
signed power-of-ten exponent applied to the raw value |
[4..5] |
weight, LE16 (LSB, MSB) |
DYMO vendor id 0x0922; the M5 is pid 0x8009. Quirk: the very first frame
right after a tare reports unit 0x00.
Interactions
Section titled “Interactions”| With | How |
|---|---|
| Firebase (account database) | Writes live weight to the user’s account |
| Tiger Studio / Connect | Display live weight; health monitoring |
- V3 (current): Tiger-Scale-V3 (MIT)
- V2: Tiger-Scale (MIT)
Related: Inventory & cloud sync