neorv32/sw/example/demo_onewire/main.c

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// #################################################################################################
// # << NEORV32 - ONEWIRE (1-Wire Interface) Demo Program >> #
// # ********************************************************************************************* #
// # BSD 3-Clause License #
// # #
// # Copyright (c) 2023, Stephan Nolting. All rights reserved. #
// # #
// # Redistribution and use in source and binary forms, with or without modification, are #
// # permitted provided that the following conditions are met: #
// # #
// # 1. Redistributions of source code must retain the above copyright notice, this list of #
// # conditions and the following disclaimer. #
// # #
// # 2. Redistributions in binary form must reproduce the above copyright notice, this list of #
// # conditions and the following disclaimer in the documentation and/or other materials #
// # provided with the distribution. #
// # #
// # 3. Neither the name of the copyright holder nor the names of its contributors may be used to #
// # endorse or promote products derived from this software without specific prior written #
// # permission. #
// # #
// # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS #
// # OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF #
// # MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE #
// # COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, #
// # EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE #
// # GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED #
// # AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING #
// # NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED #
// # OF THE POSSIBILITY OF SUCH DAMAGE. #
// # ********************************************************************************************* #
// # The NEORV32 Processor - https://github.com/stnolting/neorv32 (c) Stephan Nolting #
// #################################################################################################
/**********************************************************************//**
* @file demo_onewire/main.c
* @author Stephan Nolting
* @brief Demo program for the NEORV32 1-Wire interface controller (ONEWIRE).
**************************************************************************/
#include <neorv32.h>
#include <string.h>
// device search algorithm
#include "onewire_aux.h"
/**********************************************************************//**
* @name User configuration
**************************************************************************/
/**@{*/
/** UART BAUD rate */
#define BAUD_RATE 19200
/**@}*/
// Constants
const char hex_c[16] = {'0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f'};
// Prototypes
void show_help(void);
void show_1wire_commands(void);
void read_byte(void);
void write_byte(void);
void scan_bus(void);
uint32_t hexstr_to_uint(char *buffer, uint8_t length);
void onewire_firq_handler(void);
/**********************************************************************//**
* Main function
*
* @note This program requires the ONEWIRE and UART0 modules. Only non-blocking ONEWIRE functions are used.
*
* @return !=0 if setup error
**************************************************************************/
int main() {
// capture all exceptions and give debug info via UART0
neorv32_rte_setup();
// setup UART at default baud rate, no interrupts
neorv32_uart0_setup(BAUD_RATE, 0);
// check if ONEWIRE is implemented at all
if (!neorv32_onewire_available()) {
neorv32_uart0_printf("Error! ONEWIRE module not synthesized!\n");
return -1;
}
// intro
neorv32_uart0_printf("\n\n<<< NEORV32 1-Wire Interface (ONEWIRE) Demo Program >>>\n\n");
// configure ONEWIRE base time
neorv32_uart0_printf("Configuring ONEWIRE time base...\n");
uint32_t t_base_ref = 10000; // reference: t_base = 10000ns = 10us
uint32_t t_base_real = neorv32_onewire_setup(t_base_ref);
neorv32_uart0_printf("t_base: requested = %u ns\n"
" actual value = %u ns\n"
" difference = %i ns\n\n", t_base_ref, t_base_real, ((int)t_base_ref)-((int)t_base_real));
// check bus state - should be high (pulled-high by the pull-up resistor)
neorv32_uart0_printf("Checking bus state... ");
if (neorv32_onewire_sense() != 0) { // bus high?
neorv32_uart0_printf("OK\n");
}
else {
neorv32_uart0_printf("FAILED! Short circuit? Missing pull-up resistor?\n");
}
/*
// install "ONEWIRE operation done interrupt" - this is optional
neorv32_uart0_printf("Installing ONEWIRE 'operation done' interrupt handler...\n");
neorv32_rte_handler_install(ONEWIRE_RTE_ID, onewire_firq_handler);
neorv32_cpu_irq_enable(ONEWIRE_FIRQ_ENABLE); // enable ONEWIRE FIRQ
neorv32_cpu_eint(); // enable global interrupt flag
*/
neorv32_uart0_printf("Starting interactive user console...\n\n");
// show all available commands
show_help();
// console loop
while(1) {
neorv32_uart0_printf("CMD:> ");
char cmd = neorv32_uart0_getc();
neorv32_uart0_putc(cmd); // echo
neorv32_uart0_printf("\n");
if (cmd == 'h') {
show_help();
}
else if (cmd == 'c') {
show_1wire_commands();
}
else if (cmd == 'x') {
neorv32_uart0_printf("Sending reset pulse.\n");
if (neorv32_onewire_reset_blocking()) { neorv32_uart0_printf("No presence detected.\n"); }
else { neorv32_uart0_printf("Device presence detected!\n"); }
}
else if (cmd == '0') {
neorv32_uart0_printf("Writing 0-bit\n");
neorv32_onewire_write_bit_blocking(0);
}
else if (cmd == '1') {
neorv32_uart0_printf("Writing 1-bit\n");
neorv32_onewire_write_bit_blocking(1);
}
else if (cmd == 'b') {
neorv32_uart0_printf("Read bit = %c\n", '0' + (neorv32_onewire_read_bit_blocking() & 1));
}
else if (cmd == 'r') {
read_byte();
}
else if (cmd == 'w') {
write_byte();
}
else if (cmd == 'p') {
if (neorv32_onewire_sense()) { neorv32_uart0_printf("Bus is HIGH.\n"); }
else { neorv32_uart0_printf("Bus is LOW.\n"); }
}
else if (cmd == 's') {
scan_bus();
}
else if ((cmd == 10) || (cmd == 13)) { // line break (enter)
continue;
}
else {
neorv32_uart0_printf("Invalid command. Type 'h' to see the help menu.\n");
}
}
return 0; // should never be reached
}
/**********************************************************************//**
* Show help menu.
**************************************************************************/
void show_help(void) {
neorv32_uart0_printf("Available commands:\n"
" h: Show this text\n"
" c: Show standard 1-Wire commands\n"
" x: Generate reset pulse and check for device presence\n"
" 0: Write single '0' bit\n"
" 1: Write single '1' bit\n"
" b: Read single bit\n"
" r: Read full-byte\n"
" w: Write full-byte\n"
" p: Probe current bus state\n"
" s: Scan bus (get IDs from all devices)\n");
}
/**********************************************************************//**
* Show standard 1-wire commands.
**************************************************************************/
void show_1wire_commands(void) {
neorv32_uart0_printf("Standard 1-wire command bytes:\n"
" 0x33 - Read ROM (for identification)\n"
" 0x55 - Match ROM (access specific device)\n"
" 0xF0 - Search ROM (for device search algorithm)\n"
" 0xCC - Skip ROM (skip addressing)\n");
}
/**********************************************************************//**
* Read full byte from bus.
**************************************************************************/
void read_byte(void) {
int i;
uint8_t tmp = neorv32_onewire_read_byte_blocking();
neorv32_uart0_printf("Read byte = 0b");
// print binary
for (i=7; i>=0; i--) {
if (tmp & (1 << i)) {
neorv32_uart0_putc('1');
}
else {
neorv32_uart0_putc('0');
}
}
// print hexadecimal
neorv32_uart0_printf(" (0x");
neorv32_uart0_putc(hex_c[(tmp >> 4) & 0x0f]);
neorv32_uart0_putc(hex_c[(tmp >> 0) & 0x0f]);
neorv32_uart0_printf(")\n");
}
/**********************************************************************//**
* Write full byte to bus.
**************************************************************************/
void write_byte(void) {
char terminal_buffer[4];
// enter address
neorv32_uart0_printf("Enter write data (2 hex chars): 0x");
neorv32_uart0_scan(terminal_buffer, 2+1, 1); // 2 hex chars for address plus '\0'
uint8_t wdata = (uint8_t)hexstr_to_uint(terminal_buffer, strlen(terminal_buffer));
// write to bus
neorv32_uart0_printf("\nWriting 0x");
neorv32_uart0_putc(hex_c[(wdata >> 4) & 0x0f]);
neorv32_uart0_putc(hex_c[(wdata >> 0) & 0x0f]);
neorv32_onewire_write_byte_blocking(wdata);
neorv32_uart0_printf("\n");
}
/**********************************************************************//**
* Scan bus for devices and print IDs.
**************************************************************************/
void scan_bus(void) {
neorv32_uart0_printf("Scanning bus...\n");
// APPLICATION NOTE 187 "1-Wire Search Algorithm" by Maxim Integrated
// modified for the NEORV32 Processor
int res, i, cnt;
cnt = 0;
res = OWFirst();
while (res) {
neorv32_uart0_printf(" > Family code: 0x");
neorv32_uart0_putc(hex_c[(ROM_NO[0] >> 4) & 0x0f]);
neorv32_uart0_putc(hex_c[(ROM_NO[0] >> 0) & 0x0f]);
neorv32_uart0_printf(", ID: ");
for (i=6; i>0; i--) {
neorv32_uart0_putc('0');
neorv32_uart0_putc('x');
neorv32_uart0_putc(hex_c[(ROM_NO[i] >> 4) & 0x0f]);
neorv32_uart0_putc(hex_c[(ROM_NO[i] >> 0) & 0x0f]);
if (i != 1) {
neorv32_uart0_putc(' ');
}
}
neorv32_uart0_printf(", CRC: 0x");
neorv32_uart0_putc(hex_c[(ROM_NO[7] >> 4) & 0x0f]);
neorv32_uart0_putc(hex_c[(ROM_NO[7] >> 0) & 0x0f]);
neorv32_uart0_printf("\n");
cnt++;
res = OWNext();
}
neorv32_uart0_printf("Devices found: %u\n", cnt);
}
/**********************************************************************//**
* Helper function to convert N hex char string into uint32_t.
*
* @param[in] buffer Pointer to array of chars to convert into number.
* @param[in] length Length of the conversion string.
* @return Converted 32-bit number.
**************************************************************************/
uint32_t hexstr_to_uint(char *buffer, uint8_t length) {
uint32_t res = 0, d = 0;
char c = 0;
while (length--) {
c = *buffer++;
if ((c >= '0') && (c <= '9'))
d = (uint32_t)(c - '0');
else if ((c >= 'a') && (c <= 'f'))
d = (uint32_t)((c - 'a') + 10);
else if ((c >= 'A') && (c <= 'F'))
d = (uint32_t)((c - 'A') + 10);
else
d = 0;
res = res + (d << (length*4));
}
return res;
}
/**********************************************************************//**
* ONEWIRE operation done interrupt handler.
**************************************************************************/
void onewire_firq_handler(void) {
neorv32_cpu_csr_write(CSR_MIP, ~(1 << ONEWIRE_FIRQ_PENDING)); // ack FIRQ
neorv32_uart0_printf(" <<DONE IRQ>> ");
}