The INKL-5LED device is used to measure inclination and display it on a 5-point scale represented by indicating, color-differentiated LED diodes. Power is provided by 3V CR2 battery. Two buttons are available for unit control. Device states are indicated by LEDs and/or acoustically using a piezo transducer. The measurement is ensured by an internal sensor.
The controlling microcontroller communicates with the sensor using an I2C line
An acoustic piezo transducer and indicator LEDs are connected directly to the microcontroller. These are controlled by a PWM signal in the SCTimer peripheral, which allows you to adjust their brightness. The brightness is adjustable automatically thanks to the ambient light sensor. The buttons are connected to the microcontroller without pull-resistors. These are activated inside the MCU
FUNCTION
CONNECTING THE BATTERIES
After connecting the batteries, the device is immediately switched off. In this state the device it is waiting for the measurement to be started with the SW1 button, or for the calibration to be activated with the current one by pressing SW1 and SW2 for min. 2 seconds.
ON/OFF
The SW1 – On/Off button is used to turn the device on and off. By pressing it and holding it for a while 2 seconds (Long press), the status is changed from off to on and vice versa. On and off is indicated by LEDs – a changing pattern to distinguish this state from the measurement itself. If sound is enabled, a piezo transducer is also used to indicate the transition from off to on and vice versa.
SOUND ACTIVATION/DEACTIVATION
The sound generated by the piezo transducer indicates the operating states of the device and also accompanies the indication tilt displayed by LEDs.
By pressing the button – SW2 – Fn – and holding it for 1 sec. (Short press) for activates, or deactivates the acoustic piezo transducer. By deactivating it, it is possible to extend the life of the batteries.
This state is remembered even after the device is turned off and after the batteries are disconnected (replaced).
BRIGHTNESS REGULATION
The brightness of the LEDs is regulated automatically based on the ambient light that is sensed sensor located in the upper left corner of the front side of the printed circuit board. Brightness is only detected if yellow LD4 (second from the right) is active due to the internal synchronization of the AD converter and LED brightness controls. The measured value of the brightness is digitally filtered and thus there is a moderate the time delay between the measurement and the setting of the new brightness is approx. 1 second.
The automatic function therefore ensures the setting of maximum brightness in strong ambient lighting and minimum brightness with minimum ambient lighting (in the dark). The minimum brightness is 10% of nominal.
CALIBRATION
By simultaneously pressing and holding the SW1 and SW2 buttons for min. 2 seconds from off state, the device goes into calibration mode. This mode is the indicated reverse display of the current tilt (all LEDs are on, only the current indicating tilt is off).
The device must be placed on a horizontal surface and, after stabilization, confirm the calibration by pressing buttons SW2 – Fn. The device turns off after saving the calibration. This completes the calibration and is not it is necessary to repeat it even after disconnecting/replacing the batteries
