Capture magnetic field data with exceptional detail using AS5311 and STM32F415ZG

Magneto 4 Click is based on the AS5311, a high resolution magnetic linear encoder from ams OSRAM which integrates Hall elements, a low-noise analog front-end, and a digital signal processing (DSP), on the same die. It is a System-on-Chip used for performing highly accurate measurements. It is designed to be used along with a multi-pole magnetic strip or ring. A pole length should be 1.0mm, while the strip should be placed about 3mm above the IC surface. The magnetic strip movement is translated into a 12-bit word on the output. In other words, the output is cycled from 0 to 4095 for each 2mm the strip moves. Also, this means that the movement resolution goes down to 488nm per LSB. The AS5311 can output the movement data in several different formats: it can either output the bit-string over the serial interface, or by using the 12-bit pulse-width modulated signal (PWM). The pulse width of the PWM signal starts with 1µs and is increased for every 0.488μm. The maximum pulse width is 4095µs, which corresponds to a magnet movement of 2mm. The incremental outputs allow this Click board™ to be used in place of a mechanical or optical quadrature encoder. These two outputs are phase-shifted for 90 degrees: the output A leads output B when the magnet is moving from right to left and vice-versa:

output B leads output A when the magnet is moving from left to right. The resolution of the incremental outputs is 10 bits per pole pair (1024 steps), which results in a step length of 1.95μm. An additional index pin is triggered for each pulse pair. These pins can be disabled by using the Chip Select (CS) pin: whenever the CS pin is at a HIGH logic level, all the incremental output pins (A, B, Index) are disabled (fixed at a HIGH logic state). To prevent flickering in border-conditions, there is a hysteresis of 2 LSBs implemented. The serial interface is very similar to SPI. However, depending on the correlation between the Chip Select pin and the clock signal logic state, two data modes are available: if the CS pin is pulled to a HIGH logic state (or floating) during the clock HIGH pulse, the AS5311 will report the magnitude (strength) of the magnetic field. Else, it will output the absolute linear position data. The output data contains both the magnetic/positional data bits (11 bits) and status bits (5 bits). The status report includes offset compensation status, "CORDIC" overflow status, linearity alarm status, and two magnetic field strength status bits. The AS5311 can use either two hardware pins (MagINCn, MagENCn) routed to the additional header, or two status bits within the status report. These two bits/pins are used to describe the magnitude of

the magnetic field. The datasheet refers to three different magnetic field magnitudes: green, yellow, and red. The green status represents the optimal strength of the magnetic field. The yellow status indicated that the obtained data may not be accurate, while the red status indicates that the magnetic field generated by the multi-pole strip or ring is weak and it is not recommended to use it. For proper operation of the Click board™, a multi-pole magnetic strip should be properly placed above the IC so that it can move along x-axis only. To support correct placing, the Click board™ comes with four holes, which can be used to accurately position the strip in place. Please refer to the datasheet for more details about the magnetic strip positioning. The Click board™ can work with MCUs that use with both 3.3V and 5V supply voltages. The power supply selection on this click is a bit specific: to select 3.3V, both SMD jumpers grouped under the 3.3V label should be populated, while the SMD jumper under the 5V label should not be populated. Selecting 5V is done by removing two SMD jumpers under the 3.3V label and populating one SMD jumper under the 5V label. Please note that populating all the SMD jumpers at once may lead to malfunction.

UNI Clicker is a compact development board designed as a complete solution that brings the flexibility of add-on Click boards™ to your favorite microcontroller, making it a perfect starter kit for implementing your ideas. It supports a wide range of microcontrollers, such as different ARM, PIC32, dsPIC, PIC, and AVR from various vendors like Microchip, ST, NXP, and TI (regardless of their number of pins), four mikroBUS™ sockets for Click board™ connectivity, a USB connector, LED indicators, buttons, a debugger/programmer connector, and two 26-pin headers for interfacing with external electronics. Thanks to innovative manufacturing technology, it allows you to build

gadgets with unique functionalities and features quickly. Each part of the UNI Clicker development kit contains the components necessary for the most efficient operation of the same board. In addition to the possibility of choosing the UNI Clicker programming method, using a third-party programmer or CODEGRIP/mikroProg connected to onboard JTAG/SWD header, the UNI Clicker board also includes a clean and regulated power supply module for the development kit. It provides two ways of board-powering; through the USB Type-C (USB-C) connector, where onboard voltage regulators provide the appropriate voltage levels to each component on the board, or using a Li-Po/Li

Ion battery via an onboard battery connector. All communication methods that mikroBUS™ itself supports are on this board (plus USB HOST/DEVICE), including the well-established mikroBUS™ socket, a standardized socket for the MCU card (SiBRAIN standard), and several user-configurable buttons and LED indicators. UNI Clicker is an integral part of the Mikroe ecosystem, allowing you to create a new application in minutes. Natively supported by Mikroe software tools, it covers many aspects of prototyping thanks to a considerable number of different Click boards™ (over a thousand boards), the number of which is growing every day.