Text Commands
The agent supports Tello-style text commands for simple drone control. Send a plain text string, get a plain text response. No SDK, no MAVLink knowledge, no protocol libraries needed.
This is the easiest way to control the drone programmatically. It is designed for education, quick prototyping, and beginner-friendly automation.
How it works
The text command engine listens on two ports:
| Protocol | Port | Config key |
|---|
| UDP | 8889 | scripting.text_commands.udp_port |
| WebSocket | 8890 | scripting.text_commands.websocket_port |
scripting:
text_commands:
enabled: true
udp_port: 8889
websocket_port: 8890
Sending commands
From the CLI
ados send "takeoff"
# Response: ok
ados send "forward 200"
# Response: ok
ados send "land"
# Response: ok
From Python (UDP)
import socket
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
drone = ("192.168.4.1", 8889) # Drone IP and port
def send(cmd):
sock.sendto(cmd.encode(), drone)
resp, _ = sock.recvfrom(1024)
return resp.decode()
print(send("takeoff")) # "ok"
print(send("forward 100")) # "ok"
print(send("cw 90")) # "ok"
print(send("land")) # "ok"
From the REST API
curl -X POST http://localhost:8080/api/scripting/command \
-H "X-ADOS-Key: $KEY" \
-H "Content-Type: application/json" \
-d '{"command": "takeoff"}'
From a web browser (WebSocket)
const ws = new WebSocket('ws://192.168.4.1:8890');
ws.onopen = () => {
ws.send('takeoff');
};
ws.onmessage = (event) => {
console.log('Response:', event.data);
};
Command reference
Takeoff and landing
| Command | Description | Example |
|---|
takeoff | Take off to default altitude (2m) | takeoff |
takeoff <height> | Take off to specified height in cm | takeoff 150 |
land | Land at current position | land |
Movement
All distances are in centimeters. The drone must be airborne.
| Command | Description | Range |
|---|
forward <cm> | Fly forward | 20-500 |
back <cm> | Fly backward | 20-500 |
left <cm> | Fly left | 20-500 |
right <cm> | Fly right | 20-500 |
up <cm> | Fly up | 20-500 |
down <cm> | Fly down | 20-500 |
Rotation
| Command | Description | Range |
|---|
cw <degrees> | Rotate clockwise | 1-360 |
ccw <degrees> | Rotate counter-clockwise | 1-360 |
Queries
| Command | Returns |
|---|
battery? | Battery percentage (e.g., “85”) |
speed? | Current speed in cm/s |
time? | Flight time in seconds |
height? | Current height in cm |
temp? | CPU temperature |
attitude? | Roll, pitch, yaw |
gps? | Latitude, longitude, fix type |
Control
| Command | Description |
|---|
speed <cm/s> | Set movement speed (10-100 cm/s) |
stop | Hover in place (cancel current movement) |
emergency | Emergency motor stop (immediate disarm) |
Responses
Every command returns one of:
| Response | Meaning |
|---|
ok | Command accepted and executing |
error | Command failed (followed by reason) |
| A value | Response to a query (e.g., “85” for battery) |
error: not armed
error: parameter out of range
error: no GPS fix
error: battery too low
Safety
Text commands pass through the same safety validator as the Python SDK. The validator checks pre-arm conditions, GPS fix, battery level, and geofence before allowing flight commands. The emergency command bypasses all safety checks and disarms immediately.
The emergency command kills the motors instantly, regardless of altitude. The drone will fall. Use it only as a last resort.
Education use
Text commands are inspired by the DJI Tello SDK, which is widely used in programming education (Scratch, Python courses, robotics classes). The same code patterns work:
# Works with both Tello and ADOS
import socket
import time
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
drone = ("192.168.4.1", 8889)
def send(cmd):
sock.sendto(cmd.encode(), drone)
resp, _ = sock.recvfrom(1024)
return resp.decode()
send("takeoff")
time.sleep(3)
# Fly a square
for _ in range(4):
send("forward 100")
time.sleep(2)
send("cw 90")
time.sleep(1)
send("land")
socket and time. No authentication required on the UDP port (secured by network access). Students can focus on control logic instead of protocol boilerplate.
For classroom setups, run the agent in demo mode (ados demo) on a laptop. Students send text commands over localhost UDP. No real drone needed for the programming exercises.
