Encoders are primarily categorized based on their measurement principles into optical and magnetic types. Magnetic encoders offer several advantages over optical encoders, including:

· Dust-proof, oil-resistant, and vibration-resistant

· Simplified debugging and installation

· Smaller size with equivalent precision

· Adaptability to harsh environments

According to Future Market Insights, the global encoder market is projected to grow at a compound annual growth rate (CAGR) of 7.6%, increasing from $2.3 billion in 2023 to $4.8 billion by 2033. Industrial magnetic encoders represent a key growth area with significant potential.

Geehy Magnetic Absolute Encoder Solution Overview

The MCU is the core component in encoder design, directly impacting system performance. Geehy's APM32F103xB-based magnetic absolute encoder solution supports applications requiring 16–21-bit angular resolution. It is ideal for industrial control and consumer electronics, providing precise positional data for system control.

Solution Features

· High Precision: Provides 17-bit single-turn resolution with angular accuracy < ±0.5° before calibration, and < ±0.07° after calibration.

· Low Power Consumption: Supports 16-bit multi-turn information, with static average current < 20μA during battery operation, and a 1,100 mAh battery lifespan exceeding 5 years.

· High Communication Speed: RS485 communication rate reaches 4 Mbit/s, reducing communication time and enhancing real-time data transmission.

· Compact Design: Achieves a PCB diameter as small as 35 mm, suitable for servo motors with a 40 mm flange.

Solution Block Diagram

PCB Resources and Basic Functions

Physical PCB Diagram

PCB Hardware System Block Diagram

Basic Functions

· The APM32F103xB reads single-turn positional and alarm data via SPI.

· GPIO pins are utilized to monitor two timer switch states for multi-turn information calculation.

· I2C is used for data storage/retrieval with the host device.

· USART is implemented for achieving encoder protocols and communicating with the host device.

· ADC is engaged to sample battery and main power voltages, enabling voltage monitoring and fault alerts.

Note: Due to the erase and programming time for a 1KB page in the APM32F103xB FLASH being under 2 ms, FLASH can also emulate EEPROM for storing and reading data.

Performance Advantages of the Industrial-Grade Mainstream APM32F103xB MCU

· Low Power Mode: Stop mode current as low as 12μA; Standby mode current as low as 5μA.

· Compact Package: Features a 6×6 mm QFN36 package, ideal for low-power, compact designs.

· High-Speed UART: Communication speed of up to 4.5 Mbit/s, meeting encoder protocol requirements (2.5 Mbit/s or 4 Mbit/s).

· High-Speed SPI: Maximum communication speed of 18 Mbit/s, enabling fast read/write operations for single-turn encoder chip data.

· High Reliability: Certified for IEC60730 CLASS B and IEC61508 SIL3, with an operating temperature range of −40°C to 105°C.

· High Operating Frequency: Arm® Cortex®-M3 core with a clock speed of up to 96 MHz.

Complete Software and Hardware Ecosystem: Provides comprehensive software and hardware support, including demo boards for the entire development process of magnetic absolute encoders.