135 lines
4.4 KiB
Markdown
135 lines
4.4 KiB
Markdown
# Voron filament dryer
|
||
|
||
Arduino Nano firmware for a chamber dryer with four SHT31 humidity/temperature sensors, PID heater control, and PWM fan mixing.
|
||
|
||
## Pinout (Arduino Nano)
|
||
|
||
All settings below are defined in `include/config.h`.
|
||
|
||
| Signal | Nano pin | Notes |
|
||
|--------|----------|-------|
|
||
| I2C SDA | A4 | Shared bus (Wire) |
|
||
| I2C SCL | A5 | Shared bus (Wire) |
|
||
| TCA9548A mux | I2C `0x70` | 8-channel I2C multiplexer |
|
||
| SHT31 sensors | Mux channels 2, 3, 4, 5 | One sensor per channel |
|
||
| SHT31 address | `0x44` | ADDR pin low; use `0x45` if ADDR is high |
|
||
| Fan | D5 | 24 V fan via N-channel MOSFET (hardware PWM) |
|
||
| Heater | A2 | Solid-state relay (burst control) |
|
||
|
||
USB serial: **115200 baud**.
|
||
|
||
## Dev setup
|
||
|
||
### PlatformIO
|
||
|
||
This repo uses the PlatformIO CLI (see `.vscode/tasks.json`). If PlatformIO is already installed under `~/.platformio/penv/`, use that directly — you do not need to run the web installer again.
|
||
|
||
```bash
|
||
~/.platformio/penv/bin/pio --version
|
||
~/.platformio/penv/bin/pio run # build
|
||
~/.platformio/penv/bin/pio run -t upload # flash
|
||
~/.platformio/penv/bin/pio device monitor # serial monitor
|
||
```
|
||
|
||
On Arch Linux / CachyOS, install via the package manager if you prefer:
|
||
|
||
```bash
|
||
sudo pacman -S platformio
|
||
```
|
||
|
||
If upload cannot find the port, add to `platformio.ini`:
|
||
|
||
```ini
|
||
upload_port = /dev/ttyUSB0 ; or /dev/ttyACM0, or a /dev/serial/by-id/... path
|
||
monitor_port = /dev/ttyUSB0
|
||
```
|
||
|
||
List available ports:
|
||
|
||
```bash
|
||
ls -la /dev/serial/by-id/
|
||
```
|
||
|
||
### Serial port permissions (Linux)
|
||
|
||
**Recommended — udev rules (one-time, works in Cursor without re-login):**
|
||
|
||
```bash
|
||
sudo ./scripts/install-udev-rules.sh
|
||
# unplug and replug the Arduino
|
||
```
|
||
|
||
This installs PlatformIO’s `99-platformio-udev.rules` (covers CH340 clone Nanos and other common adapters).
|
||
|
||
**Alternative — group membership:**
|
||
|
||
```bash
|
||
# Arch / CachyOS
|
||
sudo usermod -aG uucp $USER
|
||
```
|
||
|
||
You must **fully log out of the desktop** (not just reboot or open a new terminal) so `id` shows the new group. Cursor’s terminal often keeps the old group list until you restart Cursor after logging out.
|
||
|
||
**Immediate workaround** (no sudo, current terminal only):
|
||
|
||
```bash
|
||
sg uucp -c "$HOME/.platformio/penv/bin/pio run -t upload"
|
||
```
|
||
|
||
Verify access: `test -w /dev/ttyUSB0 && echo ok`
|
||
|
||
## First run
|
||
|
||
1. Flash firmware and open the serial monitor at 115200 baud.
|
||
2. Confirm `TCA9548A detected` and four valid sensor channels (`ch2`–`ch5`).
|
||
3. Find **stir fan** speed (optional — default is **PWM 178**, ~70%):
|
||
|
||
```
|
||
target 0
|
||
fanchars
|
||
```
|
||
|
||
Sweeps **30%, 100%, 60%, 80%** fan — heats to max **60°C** corner at **100%** heater. Cools to **40°C** avg between runs. Skips a fan speed if 60°C isn't reached in time. Optional midpoint refine if best isn't at 30% or 100%. Or: `python3 scripts/fan_characterize.py`. When done, `fanchars save` writes the winner to EEPROM (or skip and keep the 178 default).
|
||
|
||
4. Tune **heat PI** (stored in EEPROM on autotune complete):
|
||
|
||
```
|
||
target 0
|
||
pid default
|
||
autotune 50
|
||
```
|
||
|
||
Emergency cutoff is fixed at **70°C** — you can autotune at 50–55°C with ABS in the chamber while hot corners stay below that.
|
||
|
||
5. Dry at your target — fan runs at the stir PWM (default **178**) unless you override with `fan <pwm>`; `fan auto` returns to the default.
|
||
|
||
Send `help` over serial for all commands (`target`, `fanchars`, `fan`, `log on/off`, `status`, `pid`, etc.).
|
||
|
||
## Raspberry Pi control
|
||
|
||
On the Pi, use the curses TUI to set targets and monitor the chamber (SSH with a TTY: `ssh -t`):
|
||
|
||
```bash
|
||
python3 scripts/capture_csv.py tui
|
||
```
|
||
|
||
Keys: `0` idle · `t` target · `p` material presets · `f`/`F` fan · `l` CSV log · `a` autotune · `:` command · `q` quit
|
||
|
||
Headless CSV-only logging (e.g. systemd) is documented in [pi-instructions.md](pi-instructions.md).
|
||
|
||
## Filament drying table
|
||
|
||
| Filament | Dryer temperature | Drying time (hours) |
|
||
|----------|-------------------|---------------------|
|
||
| PLA | 50–55 °C (122–131 °F) | > 6 |
|
||
| ABS | 60–65 °C (140–149 °F) | > 6 |
|
||
| PETG | 60–65 °C (140–149 °F) | > 6 |
|
||
| Nylon | 70–75 °C (158–167 °F) | > 24 |
|
||
| Desiccants | 60–65 °C (149 °F) | > 12 |
|
||
| PVA | 40–45 °C (104–113 °F) | > 24 |
|
||
| TPU/TPE | 50–55 °C (122–131 °F) | > 8 |
|
||
| ASA | 60–65 °C (140–149 °F) | > 8 |
|
||
| PP | 50–55 °C (122–131 °F) | > 6 |
|
||
| HIPS | 60–65 °C (140–149 °F) | > 8 |
|
||
| PC | 70–75 °C (158–167 °F) | > 12 |
|
||
| PEEK | 120–125 °C (248–257 °F) | > 24 | |