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Document icon-probe results; keep iconfinder bitprobe as artifact

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Probed remaining frame bytes for Bluetooth/power icons on a blank panel:
- found cross-wired glyph dots (byte0 bit7, byte4 bit7) and an I2C timeout
  (byte8 bit4), but no standalone icon bits
- waveshare reference does not drive these icons; likely multi-bit or
  unpopulated on the glass (cosmetic, deprioritized)
- restore temphummon.c as the active firmware build in CMakeLists
This commit is contained in:
temphummon dev 2026-09-24 17:44:02 +00:00
commit d9bac7cf28
2 changed files with 64 additions and 59 deletions
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15
PROJECT_MEMORY.md
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@ -93,6 +93,20 @@ All three are **bit 5 (0x20) of the SECOND byte of the pair**, matching the manu
| **Decimal point (bottom)** | `f[8]` | bit 5 (0x20) | after bottom-line **ones** → `88.8` |
| **% sign (humidity)** | `f[10]` | bit 5 (0x20) | after bottom-line **tenths** → `88.8%` |
### Bluetooth / power icons (probed — NOT found, likely multi-bit or unpopulated)
A single-bit probe of the remaining frame bytes (0 bits5-7, 4/8/10 bits 4/6/7,
14 all) found **no standalone Bluetooth or battery/power icon**. Bits found:
- byte 0 bit7 → a cross-wired glyph dot (top-ones region)
- byte 4 bit7 → a cross-wired glyph dot (bottom-ones region)
- byte 8 bit4 → caused an **I²C hardware timeout**
- most other candidate bits → blank
The Waveshare reference code does NOT drive any Bluetooth/power icon, and the
IST7134 datasheet doesn't name one either. Conclusion: if the icons exist on
the glass they are **multi-bit patterns** (like °C = 0x05), not a simple single
bit reachable by a bare frame write — not worth more bench time. Cosmetic only.
### Verified glyph segment map (from probing)
For a digit byte-pair, the **first byte** = left column + horizontal bars, the
@ -259,6 +273,7 @@ nix run .#flash
- [x] **Port Waveshare digit lookup table** — all 10 digits (0–9) verified working on the display
- [x] **Internal temperature sensor** — reads ESP32-H2 internal temp sensor, shows on display line 1, updates every 1s
- [x] **Find decimal point & % bits** — probing session mapped them: `f[4]/f[8]` bit5 = decimals, `f[10]` bit5 = %
- [~] **Power/Bluetooth icons** — single-bit probe found no standalone icon bits; likely multi-bit patterns or unpopulated (cosmetic, deprioritized)
- [ ] **Add humidity sensor** — wire up an external I²C sensor (SHT40, BME280, etc.) and show on display line 2
- [ ] **Configure Matter/Thread** — enable OpenThread / Matter components in `sdkconfig`
- [ ] **Implement Matter cluster** — temperature and humidity measurement clusters