Create general-purpose data selector with TMUX1308 and STM32F767BI
Analog multiplexer
Published Mar 06, 2023
Click board™
Analog MUX 4 Click
Dev.Board
Clicker 4 for STM32
Compiler
NECTO Studio
MCU
STM32F767BI
Choose one of many analog data inputs
A
A
Hardware Overview
How does it work?
Analog MUX 4 Click is based on the TMUX1308, a general-purpose 8:1 single-ended CMOS analog multiplexer from Texas Instruments. The TMUX1308 multiplexer allows for multiple inputs/sensors to be monitored with a single AN pin of the mikroBUS™ socket supporting bidirectional analog and digital signals ranging from 0 to 5V. It has an internal injection current control eliminating the need for external diode and resistor networks to protect the switch, keeping the input signals within the supply voltage. The internal injection current control circuitry allows signals on disabled signal paths to exceed the supply voltage without affecting the signal of the enabled signal path.
Alongside internal injection current control, the TMUX1308 also has another protection feature, called Break-before-make delay, which represents a safety feature preventing two inputs from connecting when the device is switching. The output first breaks from the ON-state switch before connecting with the next ON-state switch. This time delay between the break and the make is known as the break-before-make delay. This Click board™ communicates with MCU using several GPIO pins. It can be enabled or disabled through the EN pin of the mikroBUS™ socket, hence, offering a switch operation to turn ON/OFF power delivery to the TMUX1308. It also provides three address signals, labeled from A0 to A2, that control
the switch configuration and determine the activation of the desired analog input channel based on their setup. Also, each analog input has a jumper for its hardware activation or deactivation and capacitors for additional filtering of the input channels. 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 4 for STM32 is a compact development board designed as a complete solution 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 ARM Cortex-M4 microcontroller, the STM32F767BI from STMicroelectronics, four mikroBUS™ sockets for Click board™ connectivity, a USB connector, LED indicators, buttons, a debugger/programmer connector, two 23-pin headers for interfacing with external electronics, and more. Thanks to innovative manufacturing technology, it allows you to build gadgets with
unique functionalities and features quickly. Each part of the Clicker 4 for STM32 development kit contains the components necessary for the most efficient operation of the same board. In addition to the possibility of choosing the Clicker 4 for STM32 programming method, using an external CODEGRIP or mikroProg programmer connected to the onboard JTAG/SWD header, the Clicker 4 board also includes a clean and regulated power supply block. It provides several ways of board-powering; through the USB Type-C (USB-C) connector using a power supply delivered by the USB HOST (i.e., personal computer), USB wall
adapter, or a Li-Po/Li-Ion battery via an onboard battery connector. All communication methods that mikroBUS™ itself supports are on this board (plus USB-DEVICE), including the well-established mikroBUS™ socket, several user-configurable buttons, and LED indicators. Clicker 4 for STM32 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
ARM Cortex-M7
MCU Memory (KB)
2048
Silicon Vendor
STMicroelectronics
Pin count
208
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 4 for STM32 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 Analog MUX 4 Click driver.
Key functions:
analogmux4_enable_inputThis function enables analog inputs.analogmux4_read_an_pin_voltageThis function reads the results of the AD conversion of the AN pin and converts them to a proportional voltage level.analogmux4_set_input_channelThis function sets the analog input channel.
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 Analog MUX 4 Click Example.
*
* # Description
* This example demonstrates the use of Analog MUX 4 click board.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes the driver and enables the analog inputs.
*
* ## Application Task
* Reads and displays the voltage of all channels on the USB UART approximately once per second.
*
* @note
* The channel's voltage will "float" when the voltage source is not connected to it.
*
* @author Stefan Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "analogmux4.h"
static analogmux4_t analogmux4; /**< Analog MUX 4 Click driver object. */
static log_t logger; /**< Logger object. */
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
analogmux4_cfg_t analogmux4_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.
analogmux4_cfg_setup( &analogmux4_cfg );
ANALOGMUX4_MAP_MIKROBUS( analogmux4_cfg, MIKROBUS_1 );
if ( ADC_ERROR == analogmux4_init( &analogmux4, &analogmux4_cfg ) )
{
log_error( &logger, " Application Init Error. " );
log_info( &logger, " Please, run program again... " );
for ( ; ; );
}
analogmux4_enable_input ( &analogmux4 );
log_info( &logger, " Application Task " );
}
void application_task ( void )
{
float analogmux4_an_voltage = 0;
for ( uint8_t cnt = ANALOGMUX4_CHANNEL_0; cnt <= ANALOGMUX4_CHANNEL_7; cnt++ )
{
analogmux4_set_input_channel ( &analogmux4, cnt );
if ( ADC_ERROR != analogmux4_read_an_pin_voltage ( &analogmux4, &analogmux4_an_voltage ) )
{
log_printf( &logger, " AN%u voltage : %.3f V\r\n", ( uint16_t ) cnt, analogmux4_an_voltage );
}
}
log_printf( &logger, "\r\n" );
Delay_ms( 1000 );
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END
