Crowbits-LED Bar is a digital output module, it can display battery power, voltage value, water depth, sound size and any other scene that needs to represent the gradient value.
Through a dedicated LED driver chip (MY9221), serial displacement input and parallel output, two input signal lines can be used to simultaneously control the lighting of multiple LED lights. When the output of the MY9221 is high, Then the level of IO port is equal to the VCC level, so it cannot form a circuit to the ground, and the lamp will not be on if there is no current flowing through it. If the output of the MY9221 is low, then the lamp will pass from the VCC through the resistor to the ground to form a circuit, so the lamp is on. Then input different data from the data input port, After the code of MY9221, it can control the switching on and off of multiple IO ports. So as to send different data to MY9221 according to the external battery power value, voltage value, water depth and sound level to control the switching on and off of a different number of lights, which is directly reflected by the number of LED lights.
It can be used in conjunction with other modules to display the LED light bar after various signals are detected.