MIKROE Accel 20 Click is a compact add-on board that contains an acceleration sensor. This board features the KX134-1211, a digital output 3-axis accelerometer optimized for machine condition monitoring from Rohm Semiconductor. It allows selectable full-scale acceleration measurements in ranges of ±8g, ±16g, ±32g, or ±64g in three axes with a configurable host interface that supports both SPI and I2C serial communication. It also features an Advanced Data Path (ADP) technology which allows noise filtering and sensor signal processing, usually carried out by the MCU, to be performed by the accelerometer. They contribute to reducing MCU load and power consumption together with improved application performance. This Click board™ is suitable for various applications such as vibration and condition monitoring, test and measurements, predictive maintenance, and more.

Accel 20 Click as its foundation uses the KX134-1211, a highly reliable digital triaxial acceleration sensor with a feature set optimized for machine condition monitoring from Rohm Semiconductor. The KX134-1211 is highly configurable with a programmable acceleration range of ±8/±16/±32/±64g providing signal conditioning and intelligent user-programmable application algorithms with improved linearity over the entire temperature range. It also has an Advanced Data Path (ADP) technology which allows noise filtering and sensor signal processing, usually carried out by the MCU, to be performed by the accelerometer. They contribute to reducing MCU load and power consumption together with improved application performance.

Acceleration sensing is based on the principle of a differential capacitance arising from the acceleration-induced motion of the sensing element, which is hermetically sealed at the wafer level by bonding a second silicon lid wafer to the device wafer, further utilizing a standard mode cancellation to decrease errors from process variation, temperature, and environmental stress.

The KX134-1211 also features an advanced Wake-Up and Back-to-Sleep detection with a high-resolution threshold capability configurable down to 15.6mg, 512-byte buffer that continues to record data even when being read, as well as embedded engines for orientation, directional/double-tap, and free-fall detection.

Accel 20 Click allows using both I2C and SPI interfaces with a maximum frequency of 3.4MHz for I2C and 10MHz for SPI communication. The selection can be made by positioning SMD jumpers labeled as COMM SEL to an appropriate position. Note that all the jumpers' positions must be on the same side, or the Click board™ may become unresponsive. While the I2C interface is selected, the KX134-1211 allows choosing the least significant bit (LSB) of its I2C peripheral address using the SMD jumper labeled ADDR SEL. The Accel 20 also possesses two interrupts, I1 and I2, routed to the INT and AN pins on the mikroBUS™ used to signal MCU that an event has been sensed, and one trigger pin labeled as TRG, routed to the PWM pins on the mikroBUS™ socket, used for FIFO buffer control.

This Click board™ can be operated only with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before use with MCUs with different logic levels. However, the Click board™ comes equipped with a library containing functions and an example code that can be used, as a reference, for further development.

• Interface: I²C, SPI
• Compatibility: mikroBUS™
• Dimensions: 28.6 x 25.4mm
• Input Voltage: 3.3V
• Acceleration Range: Min. ±8g, Max. ±64g
• Sensitivity: 4096 counts/g
• Resolution: 16 bit
• Operating Temperature Range: Min. -40°C, Typ. +25°C, Max. +105°C

• Schematic
• KX134-1211 Datasheet
• mikroSDK
• LibStock