AS5047P – Arduino Library

High-level, type-safe SPI driver for ams/TA AS5047P (and compatible AS5x47 parts). Read 14-bit angles, magnitude, and diagnostics with concise APIs—works on classic Arduino, Feather, Teensy, and other SPI-capable boards.

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Table of Contents

• AS5047P – Arduino Library
  • Table of Contents
  • Features
  • Supported Sensors
  • Installation
    • Arduino Library Manager
    • Manual
    • PlatformIO
  • Hardware Setup
    • SPI Pins & Power Notes
    • Quick Wiring Tables
      • Arduino Uno
      • Adafruit Feather M0 (3.3 V logic)
  • Quick Start
  • Advanced Usage
    • Error & Diagnostic Handling
    • Low-level Register Access
  • Documentation
  • Troubleshooting
  • Project Status
  • License
    • Acknowledgements

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Features

• ✅ 14-bit angle readout (raw or DAE-compensated)
• ✅ Magnitude (CMAG) & diagnostics (AGC, CORDIC overflow, field strength)
• ✅ Clean C++ types for all registers and SPI frames (with parity helpers)
• ✅ Even parity verification over 15 LSBs (MSB parity bit handled for you)
• ✅ Arduino-style, minimal API + detailed status strings
• ✅ Examples for quick bring-up

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Supported Sensors

This library targets AS5047P and is compatible with several AS5x47 variants that share the same SPI framing:

• AS5047P, AS5047D, AS5147, AS5147P, AS5247

Not supported: AS5047U, AS5147U, AS5247U (different protocol/regs).

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Installation

Arduino Library Manager

1. Sketch → Include Library → Manage Libraries…
2. Search AS5047P, then Install.

You’ll need Arduino IDE ≥ 1.6.2 for Library Manager.

Manual

1. Download the latest Release ZIP.
2. Extract to your Arduino libraries/ folder.
3. Restart the IDE.

PlatformIO

pio lib install "jonas-merkle/AS5047P"

Or add to platformio.ini:

lib_deps = jonas-merkle/AS5047P

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Hardware Setup

SPI Pins & Power Notes

• SPI mode: MODE1 (CPOL=0, CPHA=1), MSB first

• Voltage:

  • Many dev boards (Feather M0, Teensy 3.x/4.x) are 3.3 V only → power sensor @ 3.3 V
  • Classic Arduino Uno/Mega can power at 5 V, but confirm logic levels and your breakout’s level shifting.

• CS pin defaults to D9, configurable in the constructor.

Quick Wiring Tables

Arduino Uno

AS5047P	Uno	Notes
GND	GND	Ground
VDD	5V	Sensor Vcc
VDD3V	NC	—
MOSI	11	SPI MOSI
MISO	12	SPI MISO
CLK	13	SPI SCK
CSn	9	Chip Select (configurable)

Adafruit Feather M0 (3.3 V logic)

AS5047P	Feather M0	Notes
GND	GND	Ground
VDD	3V	3.3 V only
VDD3V	3V	Tie to 3.3 V if required by board
MOSI	MOSI	SPI MOSI
MISO	MISO	SPI MISO
CLK	SCK	SPI SCK
CSn	9	Chip Select (configurable)

⚠️ 3.3 V ONLY on Feather/Teensy. Do not feed 5 V.

Teensy 3.5/3.6/4.0/4.1 use their standard SPI pins (MOSI/MISO/SCK) and a free GPIO for CS (e.g., 10). Power @ 3.3 V.

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Quick Start

#include <SPI.h>
#include <AS5047P.h>

// CS pin 9, SPI speed default from library header (can pass a custom speed)
AS5047P as5047p(9);

void setup() {
  Serial.begin(115200);
  // Initialize SPI via library and verify connectivity
  if (!as5047p.initSPI()) {
    Serial.println("AS5047P init failed. Check wiring and power.");
    while (true) { delay(1000); }
  }
}

void loop() {
  // Read 14-bit angle (degrees) with DAE compensation
  float deg = as5047p.readAngleDegree(true);
  Serial.print("Angle (deg): ");
  Serial.println(deg, 3);

  // Read magnitude
  uint16_t mag = as5047p.readMagnitude();
  Serial.print("Magnitude: ");
  Serial.println(mag);

  delay(500);
}

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Advanced Usage

Error & Diagnostic Handling

You can request parity verification and collect communication/sensor diagnostics on each read:

AS5047P_Types::ERROR_t err;
float deg = as5047p.readAngleDegree(
  /*withDAEC*/ true,
  /*errorOut*/ &err,
  /*verifyParity*/ true,
  /*checkForComError*/ true,
  /*checkForSensorError*/ true
);

if (!err.noError()) {
  Serial.println(err.toArduinoString()); // nicely formatted error report
}

You can also dump a combined status block:

Serial.println(as5047p.readStatusAsArduinoString());

Low-level Register Access

Typed wrappers let you work with registers directly:

// Read DIAAGC (AGC, LF, COF, MAGH/L)
AS5047P_Types::DIAAGC_t dia = as5047p.read_DIAAGC(/*errorOut*/ nullptr, /*verifyParity*/ true);

// Write to SETTINGS1 (example: toggle DAE compensation disable bit)
AS5047P_Types::SETTINGS1_t s1 = as5047p.read_SETTINGS1();
s1.data.values.DAECDIS = 1; // disable DAE
AS5047P_Types::ERROR_t err;
bool ok = as5047p.write_SETTINGS1(&s1, &err, /*checkForComError*/ true, /*verifyWittenReg*/ true);
if (!ok) Serial.println(err.toArduinoString());

Parity for frames is handled internally by the SPI layer; you can also use AS5047P_Util::parityCheck() if you construct frames yourself.

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Documentation

• Master: https://jonas-merkle.github.io/AS5047P/docs/master/html/index.html
• Develop: https://jonas-merkle.github.io/AS5047P/docs/develop/html/index.html

Doxygen is generated from the extensively commented headers and sources.

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Troubleshooting

• initSPI() fails

  • Check power (3.3 V vs 5 V board), common ground, and CS pin number.
  • Verify SPI mode 1 (the library sets this), and that no other library reconfigures SPI mid-flight.
  • If multiple SPI users exist, consider enabling AS5047P_SPI_ARDUINO_INIT_ON_COM_ENAB in util/AS5047P_Settings.h.

• Random read errors

  • Try disabling the ~100 ns NOP delay (AS5047P_SPI_ARDUINO_USE_100NS_NOP_DELAY) or vice versa depending on your MCU clock.
  • Shorten wires; keep SPI lines tight and add GND reference near sensor.

• Angles look noisy

  • Check magnet distance/centering (MAGH/MAGL flags, AGC value in DIAAGC).
  • Consider using DAE-compensated angle (readAngleDegree(true)).

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Project Status

• ✅ Read/write APIs for all relevant registers
• ✅ Parity checking & formatted error/status strings
• ✅ CI, Doxygen docs, Arduino & PlatformIO registry
• 🚧 Broader write-path testing across MCUs/clock rates
• 🚧 More examples (DAE tuning, ABI/U VW config)
• ❌ STM32 HAL backend (PRs welcome)

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License

Licensed under GNU GPLv3. See LICENSE.

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Acknowledgements

Thanks to contributors and users testing across different boards. Issues and PRs are welcome!