Quick Start

This guide will get you up and running with the AS5047U driver in just a few steps.

Prerequisites

Minimal Example

Here’s a complete working example:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27

#include "as5047u.hpp"

// 1. Implement the SPI interface
class MySpi : public as5047u::SpiInterface<MySpi> {
public:
    void transfer(const uint8_t* tx, uint8_t* rx, size_t len) {
        // Your SPI transfer implementation
        // Assert CS, transfer data, deassert CS
    }
};

// 2. Create instances
MySpi spi;
as5047u::AS5047U encoder(spi, FrameFormat::SPI_24); // 24-bit frames with CRC

// 3. Read angle
uint16_t angle = encoder.GetAngle();             // compensated angle (0-16383)
float angle_deg = angle * 360.0f / 16384.0f;    // convert to degrees

// 4. Read velocity
int16_t vel = encoder.GetVelocity();             // velocity in LSB
float vel_dps = encoder.GetVelocityDegPerSec();  // velocity in deg/s

// 5. Diagnostics
uint8_t agc = encoder.GetAGC();                  // AGC value (0-255)
uint16_t mag = encoder.GetMagnitude();           // magnetic magnitude
uint16_t errors = encoder.GetErrorFlags();       // error flags

Step-by-Step Explanation

Step 1: Include the Header 

1

#include "as5047u.hpp"

This includes the main driver class and all necessary types.

Step 2: Implement the SPI Interface

You need to implement the SpiInterface for your platform. See Platform Integration for detailed examples.

1
2
3
4
5
6
7
8

class MySpi : public as5047u::SpiInterface<MySpi> {
public:
    void transfer(const uint8_t* tx, uint8_t* rx, size_t len) {
        // Assert chip select
        // Perform SPI transfer
        // Deassert chip select
    }
};

Step 3: Create Driver Instance 

1
2

MySpi spi;
as5047u::AS5047U encoder(spi, FrameFormat::SPI_24);

The constructor takes:

  • A reference to your SPI interface implementation
  • The SPI frame format: SPI_16, SPI_24 (with CRC), or SPI_32 (with CRC)

Step 4: Read Angle 

1

uint16_t angle = encoder.GetAngle();  // 14-bit angle (0-16383)

The angle is returned as a 14-bit value (0-16383), where 0 = 0° and 16383 = 360°.

Step 5: Convert to Degrees 

1

float angle_deg = angle * 360.0f / 16384.0f;

Step 6: Read Velocity 

1
2
3

int16_t vel = encoder.GetVelocity();              // LSB units
float vel_dps = encoder.GetVelocityDegPerSec();   // degrees/second
float vel_rpm = encoder.GetVelocityRPM();         // RPM

Step 7: Check Diagnostics 

1
2
3

uint8_t agc = encoder.GetAGC();        // Automatic Gain Control (0-255)
uint16_t mag = encoder.GetMagnitude(); // Magnetic field magnitude
uint16_t errors = encoder.GetErrorFlags(); // Error flags

Complete Example with Error Handling 

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30

#include "as5047u.hpp"

class MySpi : public as5047u::SpiInterface<MySpi> {
    // ... SPI implementation
};

void app_main() {
    MySpi spi;
    as5047u::AS5047U encoder(spi, FrameFormat::SPI_24);
    
    while (true) {
        // Read angle with retry on CRC errors
        uint16_t angle = encoder.GetAngle(3); // 3 retries
        
        // Check for errors
        AS5047U_Error errors = encoder.GetStickyErrorFlags();
        if (errors != AS5047U_Error::None) {
            printf("Error detected: 0x%04X\n", static_cast<uint16_t>(errors));
        }
        
        // Read diagnostics
        uint8_t agc = encoder.GetAGC();
        uint16_t mag = encoder.GetMagnitude();
        
        printf("Angle: %u (%.2f°), AGC: %u, Mag: %u\n", 
               angle, angle * 360.0f / 16384.0f, agc, mag);
        
        vTaskDelay(pdMS_TO_TICKS(100));
    }
}

Expected Output

When running this example, you should see:

1
2
3

Angle: 8192 (180.00°), AGC: 128, Mag: 8192
Angle: 8200 (180.18°), AGC: 128, Mag: 8192
Angle: 8208 (180.35°), AGC: 128, Mag: 8192

Troubleshooting

If you encounter issues:

  • Compilation errors: Check that you’ve implemented the transfer() method in your SPI interface
  • CRC errors: Verify SPI connections and try increasing retry count
  • Zero readings: Check magnet placement and field strength
  • See: Troubleshooting for common issues

Next Steps

Navigation ⬅️ Installation | Next: Hardware Setup ➡️ | Back to Index