Build a reliable timing system with MIC1557 and PIC32MZ2048EFH100
Make sure your circuits are never out of tune
Published Apr 21, 2023
Click board™
Clock Gen 6 Click
Dev Board
Clicker 2 for PIC32MZ
Compiler
NECTO Studio
MCU
PIC32MZ2048EFH100
IttyBitty CMOS RC oscillator designed to provide rail-to-rail pulses for precise time delay or frequency generation
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Hardware Overview
How does it work?
Clock Gen 6 Click is based on the MIC1557, a low-power digital frequency solution providing the logic for creating a simple RC oscillator circuit from Microchip Technology. The MIC1557 offers rail-to-rail pulses for precise frequency generation alongside a single threshold and trigger connection, internally connected, for astable (oscillator) operation only with programmable output frequency and enable/reset control signal intended as an oscillator with a Shutdown capability. As mentioned, the astable oscillator switches between two states, ON and OFF, producing a continuous square wave. The MIC1557 is optimized for this function by tying the two comparator inputs together, the threshold, and trigger pins (THR and TRG), forming a T/T pin.
The external capacitor charges slowly through the external resistor in the form of a digital potentiometer by which the user can pass through the frequency range and thus adjust the desired output. Replacing the resistor with a digital potentiometer allows the user to program frequency output as performed on this Click board™. For this purpose, the digital potentiometer MAX5401, which communicates with the MCU via a 3-Wire SPI serial interface, is used to set the resistance on the MIC1557 OUT line, adjusting the frequency up to 5MHz. Alongside SPI communication, this Click board™ also uses one additional pin. The Enable pin, labeled as EN and routed to the RST pin of the mikroBUS™ socket, optimizes power consumption and is used for power ON/OFF purposes
(controls the bias supply to the oscillator’s internal circuitry). When the MIC1557 is deselected, the supply current is less than 1μA, and the device is placed in a Shutdown state. Forcing the EN pin low resets the device by setting the flip flop, causing the output to a low logic state. 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. However, the 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.
Features overview
Development board
Clicker 2 for PIC32MZ is a compact starter development board that brings the flexibility of add-on Click boards™ to your favorite microcontroller, making it a perfect starter kit for implementing your ideas. It comes with an onboard 32-bit PIC32MZ microcontroller from Microchip, two mikroBUS™ sockets for Click board™ connectivity, a USB connector, LED indicators, buttons, a mikroProg programmer connector, and two 26-pin headers for interfacing with external electronics. Its compact design with clear and easily recognizable silkscreen markings allows you to build gadgets with unique functionalities and features quickly.
Each part of the Clicker 2 for PIC32MZ development kit contains the components necessary for the most efficient operation of the same board. In addition to the possibility of choosing the Clicker 2 for PIC32MZ programming method, using a USB HID mikroBootloader or an external mikroProg connector for PIC, dsPIC, PIC32, the Clicker 2 board also includes a clean and regulated power supply module for the development kit. It provides two ways of board-powering; through the USB Micro-B cable, where onboard voltage regulators provide the appropriate voltage levels to each component on the board,
or using a Li-Polymer battery via an onboard battery connector. All communication methods that mikroBUS™ itself supports are on this board, including the well-established mikroBUS™ socket, reset button, and several user-configurable buttons and LED indicators. Clicker 2 for PIC32MZ 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.
Microcontroller Overview
MCU Card / MCU
Architecture
PIC32
MCU Memory (KB)
2048
Silicon Vendor
Microchip
Pin count
100
RAM (Bytes)
524288
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Schematic
Step by step
Project assembly
Start by selecting your development board and Click board™. Begin with the Clicker 2 for PIC32MZ as your development board.
Track your results in real time
Application Output
After loading the code example, pressing the "DEBUG" button builds and programs it on the selected setup.
After programming is completed, a header with buttons for various actions available in the IDE appears. By clicking the green "PLAY "button, we start reading the results achieved with Click board™.
Upon completion of programming, the Application Output tab is automatically opened, where the achieved result can be read. In case of an inability to perform the Debug function, check if a proper connection between the MCU used by the setup and the CODEGRIP programmer has been established. A detailed explanation of the CODEGRIP-board connection can be found in the CODEGRIP User Manual. Please find it in the RESOURCES section.
Software Support
Library Description
This library contains API for Clock Gen 6 Click driver.
Key functions:
clockgen6_set_digipotThis function sets the digital potentiometer position by using SPI serial interface.clockgen6_enable_outputThis function enables the output by setting the EN pin to high logic state.clockgen6_disable_outputThis function disables the output by setting the EN pin to low logic state.
Open Source
Code example
This example can be found in NECTO Studio. Feel free to download the code, or you can copy the code below.
/*!
* @file main.c
* @brief Clock Gen 6 Click Example.
*
* # Description
* This example demonstrates the use of Clock Gen 6 click board which acts as
* an astable oscillator.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes the driver and performs the click default configuration which sets the digital
* potentiometer to max position and enables the clock output.
*
* ## Application Task
* Changes the clock output frequency by changing the digital potentiometer position every second.
* The potentiometer position value will be displayed on the USB UART.
*
* @author Stefan Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "clockgen6.h"
static clockgen6_t clockgen6; /**< Clock Gen 6 Click driver object. */
static log_t logger; /**< Logger object. */
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
clockgen6_cfg_t clockgen6_cfg; /**< Click config object. */
/**
* Logger initialization.
* Default baud rate: 115200
* Default log level: LOG_LEVEL_DEBUG
* @note If USB_UART_RX and USB_UART_TX
* are defined as HAL_PIN_NC, you will
* need to define them manually for log to work.
* See @b LOG_MAP_USB_UART macro definition for detailed explanation.
*/
LOG_MAP_USB_UART( log_cfg );
log_init( &logger, &log_cfg );
log_info( &logger, " Application Init " );
// Click initialization.
clockgen6_cfg_setup( &clockgen6_cfg );
CLOCKGEN6_MAP_MIKROBUS( clockgen6_cfg, MIKROBUS_1 );
if ( DIGITAL_OUT_UNSUPPORTED_PIN == clockgen6_init( &clockgen6, &clockgen6_cfg ) )
{
log_error( &logger, " Communication init." );
for ( ; ; );
}
if ( CLOCKGEN6_ERROR == clockgen6_default_cfg ( &clockgen6 ) )
{
log_error( &logger, " Default configuration." );
for ( ; ; );
}
log_info( &logger, " Application Task " );
}
void application_task ( void )
{
for ( int16_t pos = CLOCKGEN6_DIGIPOT_POSITION_MAX; pos >= CLOCKGEN6_DIGIPOT_POSITION_MIN; )
{
if ( CLOCKGEN6_OK == clockgen6_set_digipot ( &clockgen6, pos ) )
{
log_printf( &logger, " DIGIPOT position: %u\r\n", pos );
Delay_ms ( 1000 );
pos -= 5;
}
}
}
int main ( void )
{
/* Do not remove this line or clock might not be set correctly. */
#ifdef PREINIT_SUPPORTED
preinit();
#endif
application_init( );
for ( ; ; )
{
application_task( );
}
return 0;
}
// ------------------------------------------------------------------------ END
