A compass sensor is an electronic device that detects direction. It works like a digital compass. It tells a device which way it is facing — north, south, east, or west. These sensors are common in smartphones, drones, robots, navigation systems, and outdoor gear.
Compass sensors are essential for navigation, robotics, and automotive systems. Choosing the right model depends on accuracy, tilt compensation, environment, and budget. The table above offers a quick comparison of all ATO models.
| Model | Heading Accuracy | Tilt Comp | Best For |
| ATO-CPS-SCM225 | ±1° | No | Basic navigation, automation, low-cost |
| ATO-CPS-SCM220 | ±1° | No | Single-board, cost-effective automation |
| ATO-CPS-DCM260B | 0.8° | Yes (Accel) | Antenna stabilization, vehicles, ships |
| ATO-CPS-DDM306B | 0.8° | Yes (Accel+Gyro) | Drones, ships, satellite dishes (20Hz) |
| ATO-CPS-DCM302B | 0.5° | Yes (Accel) | Industrial, outdoor, waterproof (IP67) |
| ATO-CPS-HCM365 | 0.3°–0.5° | Yes (Accel) | Full attitude, drones, robots (IP67) |
| ATO-CPS-HCM375B | 0.5° (tilt<10°) | Yes (Accel) | High accuracy, antenna stabilization (IP67) |
| ATO-CPS-DCS306 | 2°(static)/3°(dynamic) | Yes (Accel+Gyro) | Fast response (100Hz sampling), IP67 |
| ATO-CPS-HEC3500D | 0.3° | Yes (Accel+Gyro) | High precision, 20000g shock, IP67/68 |
| ATO-CPS-DCM6 | 0.5°(tilt<10°)/1.5°(tilt<85°) | Yes (Accel) | OEM module, compass applications |
Q1: What is the difference between a 2-axis compass and a 3-axis compass?
A: A 2-axis compass measures only the horizontal magnetic field. It needs a perfectly level platform. A 3-axis compass measures all three dimensions. It can compensate for tilt using an integrated accelerometer. Unless your device is permanently horizontal, always choose 3‑axis. All modern MEMS compass sensors are 3‑axis.
Q2: How do I calibrate a compass sensor in a metal enclosure?
A: Most ATO compass sensors (DDM306B, DCM260B, HEC3500D) have on‑chip hard‑iron and soft‑iron calibration. A simple one‑time field calibration — rotating the device in a figure‑8 pattern — is usually enough. If the mounting location changes, recalibrate to keep accuracy.
Q3: Why does temperature matter for heading accuracy?
A: The magnetic properties of sensor materials and nearby metals change with temperature. This causes heading drift. Many cheap sensors drift 5°–10° from -40°C to +85°C. ATO's temperature‑compensated models (like DCM260B) keep error under 0.8° across that range — critical for outdoor and automotive use.
Q4: Do I need a gyroscope in addition to a compass?
A: For static orientation, a compass (magnetometer) plus accelerometer is enough. For fast rotations (drones, UAVs, stabilization systems), a 9‑axis AHRS model like DDM306B or DCS306 includes a 3‑axis gyroscope to handle rapid angular motion accurately.