Display various signal or status properties in the form of a bar graph with JSB-R102510ZR and PIC18F57Q43

BarGraph Click is based on the JSB-R102510ZR, a bar graph LED array with ten red-colored LED segments from Ningbo, and two 74HC595, 8-bit serial-in, parallel-out shift registers with output latches from Texas Instruments to drive the JSB-R102510ZR. The 74HC595 ICs are comprised of a D-type internal storage register, as well as the serial-to-parallel shift register, both 8-bit wide. Each of these registers has its clock line, making it possible to clock in the desired data and then clock it out to the parallel output pins. The JSB-R102510ZR bar graph LED array has 10 red-colored LED segments. Each LED has its anode and cathode routed out, making each LED element absolutely independent so that it can be used in any circuit configuration. However, the JSB-R102510ZR bar graph display is connected as the display with the common cathode, meaning that all LED cathodes are connected to a single point. This LED cathode common line (CC) is connected to the drain of the N channel MOSFET, while its source is connected to the GND. Driving this MOSFET via its gate through the PWM pin of the mikroBUS™ allows dimming of the LED segments. Changing the PWM signal's duty cycle makes it possible to change the brightness of the XGURUGX10D bar graph display. The gate of this MOSFET is

connected to the PWM pin of the mikroBUS™ and it is pulled to VCC, allowing the display to work if the PWM pin is left floating. The Click board™ communicates with the host MCU via the mikroBUS™ SPI interface pins. Two bytes of information (16 bits in total) are pushed through the serial data input pin (DS) of the first 74HC595 IC, and routed to the SDI pin. The 74HC595 construction is such that after receiving 8 bits, clocking in one more bit will shift the existing 8 bits by one place, overflowing the last bit to the Q7S output pin and shifting it out that way. Since the Q7S of the first 74HC595 is connected to the DS pin of the second 74HC595, clocking 16 bits into the first 74HC595 IC will fill up both ICs with required data. Note that only two bits of the second byte will be used since the second shift register only has two outputs connected to the bar graph display (8 from the first IC + 2 from the second). It is worth mentioning that the Q7S of the last 74HC595 IC is routed to the MISO pin of the mikroBUS™, labeled as the SDO, allowing connection of multiple devices in cascade, building more complex setups. Adding more devices in the cascade would require more 8-bit words to be clocked into the first 74HC595 IC in the chain. When the data has been clocked in, the

SPI clock should be stopped, and the CS pin should be driven to a HIGH logic level. The CS pin of the mikroBUS™ is routed to the STCP pin of the 74HC595 ICs and labeled as LT on the Click board™. A rising edge on the STCP input pins of the 74HC595 ICs will latch the data from their internal storage registers to the output pins, polarizing the connected bar graph segment anodes. The onboard resistor pulls the STCP pin to a LOW logic level. If the previously mentioned MOSFET is in a conductive state, the current can flow through the LEDs, and the polarized LED elements will be lit. The #MR pin is used to clear the data in the internal storage register of the ICs. The LOW logic level on this pin will clear the content of this storage register, but it will not turn off the already activated outputs. The #MR pin is routed to the RST pin of the mikroBUS™, labeled as MR, and pulled to a HIGH logic level by the onboard resistor. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the VCC SEL jumper. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. Also, this Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used as a reference for further development.

PIC18F57Q43 Curiosity Nano evaluation kit is a cutting-edge hardware platform designed to evaluate microcontrollers within the PIC18-Q43 family. Central to its design is the inclusion of the powerful PIC18F57Q43 microcontroller (MCU), offering advanced functionalities and robust performance. Key features of this evaluation kit include a yellow user LED and a responsive

mechanical user switch, providing seamless interaction and testing. The provision for a 32.768kHz crystal footprint ensures precision timing capabilities. With an onboard debugger boasting a green power and status LED, programming and debugging become intuitive and efficient. Further enhancing its utility is the Virtual serial port (CDC) and a debug GPIO channel (DGI

GPIO), offering extensive connectivity options. Powered via USB, this kit boasts an adjustable target voltage feature facilitated by the MIC5353 LDO regulator, ensuring stable operation with an output voltage ranging from 1.8V to 5.1V, with a maximum output current of 500mA, subject to ambient temperature and voltage constraints.