WiFi Configuration

The ESP32 on the RoArm-M2-S supports three WiFi modes. The mode persists across reboots via a configuration file stored in flash.

WiFi Modes

Mode	Code	Description
Off	0	WiFi disabled
AP	1	Arm creates its own access point
STA	2	Arm joins your existing network
AP+STA	3	Both simultaneously (default)

Configuration Commands

AP Mode

Create a standalone access point. Useful for field operation without a router.

Set AP credentials:

{"T":402,"ssid":"RoArm-M2","password":"12345678"}

Enable AP-only mode on boot:

{"T":401,"cmd":1}

Connect to the RoArm-M2 network, then access the web interface at 192.168.4.1.

STA Mode

Join an existing WiFi network. The arm gets an IP from your router’s DHCP.

Set STA credentials:

{"T":403,"ssid":"YourNetwork","password":"YourPassword"}

Enable STA-only mode on boot:

{"T":401,"cmd":2}

Check the serial monitor or send {"T":405} to find the assigned IP address.

AP+STA Mode

Run both modes at once — the arm creates its own AP while also connecting to your network. This is the default mode.

Configure both simultaneously:

{"T":404,"ap_ssid":"RoArm-M2","ap_password":"12345678","sta_ssid":"YourNetwork","sta_password":"YourPassword"}

Enable AP+STA mode on boot:

{"T":401,"cmd":3}

Persisting Configuration

WiFi settings are saved to a wifiConfig.json file in the ESP32’s flash storage. Two ways to create it:

From current running config:

{"T":406}

From explicit parameters:

{"T":407,"mode":3,"ap_ssid":"RoArm-M2","ap_password":"12345678","sta_ssid":"YourNetwork","sta_password":"YourPassword"}

The arm reads this file on boot and applies the saved configuration automatically.

Checking WiFi Status

Query the current WiFi state:

{"T":405}

Returns the current mode, SSID, IP address, signal strength, and MAC address.

Disconnecting

To stop WiFi (until next reboot):

{"T":408}

Disabling WiFi on Boot

If you only need serial control, disable WiFi entirely:

{"T":401,"cmd":0}

Tip

AP+STA mode is recommended for development — you can always reach the arm via its AP at 192.168.4.1 even if your STA connection fails.

Caution

If WiFi stops working after a firmware update, clear the NVS (non-volatile storage) with {"T":604} and reconfigure.

Web Interface

Once connected via WiFi, open the arm’s IP address in a browser. The built-in web application provides:

• Joint angle sliders
• XYZ coordinate control
• Gripper open/close
• Mission recording and playback
• WiFi and servo configuration

Image: Waveshare

Command Reference

T-Code	Command	Description
401	CMD_WIFI_ON_BOOT	Set WiFi mode at boot (0/1/2/3)
402	CMD_SET_AP	Configure AP SSID and password
403	CMD_SET_STA	Configure STA SSID and password
404	CMD_WIFI_APSTA	Configure AP+STA simultaneously
405	CMD_WIFI_INFO	Query current WiFi status
406	CMD_WIFI_CONFIG_CREATE_BY_STATUS	Save current config to flash
407	CMD_WIFI_CONFIG_CREATE_BY_INPUT	Save explicit config to flash
408	CMD_WIFI_STOP	Disconnect WiFi

---

WiFi configuration reference from Waveshare Wiki and firmware source json_cmd.h.