What is it?

Ideal for small robots and motor control applications, this small sensor board measures the orientation of a nearby magnet (contactless measurement). It uses an SPI interface for communications, and can return angle values to 14bit precision – that’s 16384 counts per revolution, or 0.022° degrees.

Its tiny 21mm x 17mm dimensions mean it will fit any project, and can be easily mounted even to tiny motors or actuators using the 2.2mm holes.

The sensor can operate on 3.3V or 5V supplies (configurable via solder bridge), and features a power indication LED. The SPI interface is on a SH-1mm 6pin connector, 1 cable is included, and pre-made cables are inexpensive and easily available should you require more.

The sensor requires a small diametrically magnetized magnet (1 included, link below should you need more), which is mounted in 0.25-1mm distance from the sensor, depending on the magnet’s strength. As the magnet rotates, the sensor will report its absolute orientation.

This encoder board is based on the AMS AS5048A sensor chip (data sheet link below).

Driver code is available for Arduino framework, and is easy to use (library link below). This means it is very easy to use this sensor in your own projects, and can also be used directly with the SimpleFOC library for motor control.

What's included?

Includes:

• 1 sensor board
• 1 small magnet (typically d 6mm x h 2.5mm but may vary)
• 1 SH-1mm 6-pin cable

Why did I make it?

Existing magnetic encoder PCBs I could find to buy always seemed to have one or more of the following shortcomings - they were too large, had inconvenient bits sticking out of them, were super-expensive, required soldering wires to them, didn't offer the SPI interface or had poor accuracy/performance. This meant they didn't work in my small robot designs, or at least not in the way I wanted them to. So I decided to design my own encoder board, with none of those problems. It's plug and play, and its shape is easy to integrate into projects.

What makes it special?

• 14 bit accuracy
• fast performance
• small size
• SPI interface on SH-1mm connector
• 3.3V operation
• affordable price

The encoder design is open source, as is the software driver (for Arduino framework) provided.

Getting Help

If you have questions about this sensor board, please don't hesitate to contact me via Tindie, or please join our discord to ask questions: https://discord.gg/FwTymtVhMU

Notes

Please note that due to PCB manufacturing processes there may be small variations in finish between models.

Slightly irregular edges at the sides are normal - due to the fact the tiny PCB has to be manufactured in a panel there are tabs which have to be cut away. While our production partner makes an effort to deliver cleanly cut edges, any rough spots or burrs remaining can be easily smoothed with a nail-file or a piece of sand-paper (wear a mask!).

The 2 Euro coin shown in some photos is for size comparison. It is not included.

Links

Datasheet link:

https://ams.com/documents/20143/36005/AS5048_DS000298_4-00.pdf

Magnet link:

https://radialmagnet.com/products/n35-nicuni-6mma-x-3-0mm/

Driver source code link:

https://github.com/simplefoc/Arduino-FOC-drivers/tree/master/src/encoders/as5048a

SimpleFOC open source motor control:

https://www.simplefoc.com

Repository (documentation, support and source files):

https://github.com/runger1101001/Magnetic_Encoders/tree/master/Encoder_SPI