Guide
Serial port drivers
Install USB serial drivers when ports do not appear
For USB–serial links (Modbus RTU, etc.), First Crack’s port list stays empty until the OS has the right USB driver.
Symptoms
Section titled “Symptoms”- Empty serial port list in machine settings
- No new port when USB is plugged in
- “Cannot open port” on connect
Windows
Section titled “Windows”1. Device Manager
Section titled “1. Device Manager”Win + X → Device Manager → Ports (COM & LPT) — look for COMx.
- Unknown device or yellow bang on USB Serial means missing drivers.
2. Install drivers
Section titled “2. Install drivers”Follow the roaster or USB adapter maker. Common chipsets:
| Chipset | Driver |
|---|---|
| FTDI | FTDI VCP |
| CH340 / CH341 | Maker site or WCH |
| CP210x | Silicon Labs |
| Prolific PL2303 | Maker package |
Prefer drivers shipped with the roaster.
3. COM number
Section titled “3. COM number”After install, enter the COM number from Device Manager (e.g. COM5) in First Crack.
- Plug the adapter → System Settings → General → About → System Report → USB
- Install maker macOS drivers if needed (newer macOS may ship built-ins)
- In Terminal:
ls /dev/cu.*forcu.usbserial-*orcu.wchusbserial* - Select that
/dev/cu....port in First Crack
Still stuck
Section titled “Still stuck”- Swap USB cable/port; avoid hubs (direct to PC)
- Test the same cable on another PC
- Check roaster Modbus port and “comm ON” settings
- Troubleshooting and Contact