IP Configuration — Stepper-Ninja

Overview

The ipconfig functionality provides a serial terminal interface for configuring the stepper-ninja device at runtime. It allows setting network parameters (IP, MAC, port, etc.), managing timeouts, saving configurations to flash, and resetting the device — all without reflashing firmware.

Commands are entered via a serial connection, processed in real-time, and validated for correct formatting.

Prerequisites

A serial terminal emulator (e.g. minicom) configured to connect to /dev/ttyACM0 at 115200 8N1.
Add your user to the dialout group:

sudo usermod -a -G dialout $USER

Then log out and back in for the change to take effect.

Serial Terminal Setup (Linux)

Install minicom:

sudo apt update && sudo apt install minicom

Connect to the device:
```
minicom -D /dev/ttyACM0 -b 115200
```
Disable flow control: press Ctrl+A, then O, select Serial port setup, set F (hardware flow) and G (software flow) to No.

Supported Commands

ℹ

Commands are case-sensitive. Commands with parameters require exact formatting. Issue save after any change to persist it to flash — otherwise changes are lost on reset.

Command	Description	Example
`help`	Show available commands	`help`
`check`	Show full current config (MAC, IP, subnet, gateway, DNS, DHCP, port, PHY, timeout)	`check`
`ip <x.x.x.x>`	Set device IP address	`ip 192.168.1.100`
`ip`	Show current IP	`ip`
`port <n>`	Set UDP port	`port 5000`
`port`	Show current port	`port`
`mac <xx:xx:xx:xx:xx:xx>`	Set MAC address	`mac 00:1A:2B:3C:4D:5E`
`mac`	Show current MAC	`mac`
`timeout <µs>`	Set timeout in microseconds	`timeout 1000000`
`timeout`	Show current timeout	`timeout`
`tim <n>`	Set time constant value	`tim 500`
`defaults`	Restore factory defaults	`defaults`
`save`	Persist current config to flash	`save`
`reset` / `reboot`	Reboot device via watchdog	`reset`

Usage Example

1. Connect and check current config

minicom -D /dev/ttyACM0 -b 115200

check

Example output:

Current configuration:
MAC: 00:1A:2B:3C:4D:5E
IP: 192.168.1.100
Subnet: 255.255.255.0
Gateway: 192.168.1.1
DNS: 8.8.8.8
DHCP: 1 (1-Static, 2-Dynamic)
PORT: 5000
*******************PHY status**************
PHY Duplex: Full
PHY Speed: 100Mbps
*******************************************
Timeout: 1000000
Ready.

2. Change the IP address and save

ip 192.168.1.200

save

reset

Technical Details

Input Handling

The handle_serial_input function reads characters non-blocking via getchar_timeout_us. It ignores non-printable ASCII (except \r) and stores valid input in a 64-byte buffer. When \r is received or the buffer fills, the command is processed and the buffer is cleared.

Command Processing

process_command parses commands using strcmp and strncmp. For parameterised commands, sscanf validates input (e.g. IP, MAC, port). Changes are applied to global variables (net_info, port, TIMEOUT_US, time_constant) and saved via save_configuration.

Configuration Storage

save_configuration copies settings to a flash_config structure persisted to flash via save_config_to_flash. load_configuration initialises settings from flash on startup.

Locking Mechanism

The terminal locks when timeout_error == 0 and unlocks when timeout_error == 1.

Troubleshooting

No response from device

Verify the correct serial port: ls /dev/tty*
Ensure baud rate is 115200.
Check USB cable and device power.

Permission denied on serial port

sudo usermod -a -G dialout $USER

Garbled output

Verify baud rate, parity (8N1), and flow control (disabled) in minicom.

Invalid format errors

Ensure exact command syntax — e.g. ip 192.168.1.100, not ip 192.168.001.100.

Changes not persisted after reboot

Issue the save command before reset.

Limitations

Terminal buffer limited to 63 characters — longer commands are truncated.
The serial interface is non-blocking; rapid input may be missed if the device is busy.
The locking mechanism (based on timeout_error) may restrict access if network conditions trigger timeouts.