| 1 |
2 |
zero_gravi |
// #################################################################################################
|
| 2 |
|
|
// # << NEORV32 - PWM Demo Program >> #
|
| 3 |
|
|
// # ********************************************************************************************* #
|
| 4 |
|
|
// # BSD 3-Clause License #
|
| 5 |
|
|
// # #
|
| 6 |
|
|
// # Copyright (c) 2020, Stephan Nolting. All rights reserved. #
|
| 7 |
|
|
// # #
|
| 8 |
|
|
// # Redistribution and use in source and binary forms, with or without modification, are #
|
| 9 |
|
|
// # permitted provided that the following conditions are met: #
|
| 10 |
|
|
// # #
|
| 11 |
|
|
// # 1. Redistributions of source code must retain the above copyright notice, this list of #
|
| 12 |
|
|
// # conditions and the following disclaimer. #
|
| 13 |
|
|
// # #
|
| 14 |
|
|
// # 2. Redistributions in binary form must reproduce the above copyright notice, this list of #
|
| 15 |
|
|
// # conditions and the following disclaimer in the documentation and/or other materials #
|
| 16 |
|
|
// # provided with the distribution. #
|
| 17 |
|
|
// # #
|
| 18 |
|
|
// # 3. Neither the name of the copyright holder nor the names of its contributors may be used to #
|
| 19 |
|
|
// # endorse or promote products derived from this software without specific prior written #
|
| 20 |
|
|
// # permission. #
|
| 21 |
|
|
// # #
|
| 22 |
|
|
// # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS #
|
| 23 |
|
|
// # OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF #
|
| 24 |
|
|
// # MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE #
|
| 25 |
|
|
// # COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, #
|
| 26 |
|
|
// # EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE #
|
| 27 |
|
|
// # GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED #
|
| 28 |
|
|
// # AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING #
|
| 29 |
|
|
// # NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED #
|
| 30 |
|
|
// # OF THE POSSIBILITY OF SUCH DAMAGE. #
|
| 31 |
|
|
// # ********************************************************************************************* #
|
| 32 |
|
|
// # The NEORV32 Processor - https://github.com/stnolting/neorv32 (c) Stephan Nolting #
|
| 33 |
|
|
// #################################################################################################
|
| 34 |
|
|
|
| 35 |
|
|
|
| 36 |
|
|
/**********************************************************************//**
|
| 37 |
|
|
* @file demo_pwm/main.c
|
| 38 |
|
|
* @author Stephan Nolting
|
| 39 |
|
|
* @brief Simple PWM usage example.
|
| 40 |
|
|
**************************************************************************/
|
| 41 |
|
|
|
| 42 |
|
|
#include <neorv32.h>
|
| 43 |
|
|
|
| 44 |
|
|
|
| 45 |
|
|
/**********************************************************************//**
|
| 46 |
|
|
* @name User configuration
|
| 47 |
|
|
**************************************************************************/
|
| 48 |
|
|
/**@{*/
|
| 49 |
|
|
/** UART BAUD rate */
|
| 50 |
|
|
#define BAUD_RATE 19200
|
| 51 |
|
|
/** Maximum PWM output intensity (0..255) */
|
| 52 |
34 |
zero_gravi |
#define PWM_MAX 128
|
| 53 |
2 |
zero_gravi |
/**@}*/
|
| 54 |
|
|
|
| 55 |
|
|
|
| 56 |
|
|
/**********************************************************************//**
|
| 57 |
|
|
* This program generates a simple dimming sequence for PWM channel 0,1,2.
|
| 58 |
|
|
*
|
| 59 |
34 |
zero_gravi |
* @note This program requires the PWM controller to be synthesized (the UART is optional).
|
| 60 |
2 |
zero_gravi |
*
|
| 61 |
|
|
* @return Irrelevant.
|
| 62 |
|
|
**************************************************************************/
|
| 63 |
|
|
int main() {
|
| 64 |
|
|
|
| 65 |
|
|
// check if PWM unit is implemented at all
|
| 66 |
|
|
if (neorv32_pwm_available() == 0) {
|
| 67 |
|
|
return 0;
|
| 68 |
|
|
}
|
| 69 |
|
|
|
| 70 |
|
|
|
| 71 |
|
|
// capture all exceptions and give debug info via UART
|
| 72 |
|
|
// this is not required, but keeps us safe
|
| 73 |
14 |
zero_gravi |
neorv32_rte_setup();
|
| 74 |
2 |
zero_gravi |
|
| 75 |
|
|
|
| 76 |
42 |
zero_gravi |
// init UART at default baud rate, no parity bits, no rx interrupt, no tx interrupt
|
| 77 |
|
|
neorv32_uart_setup(BAUD_RATE, 0b00, 0, 0);
|
| 78 |
2 |
zero_gravi |
|
| 79 |
|
|
// say hello
|
| 80 |
|
|
neorv32_uart_print("PWM demo program\n");
|
| 81 |
|
|
|
| 82 |
|
|
|
| 83 |
|
|
// deativate all PWM channels
|
| 84 |
|
|
neorv32_pwm_set(0, 0);
|
| 85 |
|
|
neorv32_pwm_set(1, 0);
|
| 86 |
|
|
neorv32_pwm_set(2, 0);
|
| 87 |
|
|
neorv32_pwm_set(3, 0);
|
| 88 |
|
|
|
| 89 |
|
|
// configure and enable PWM
|
| 90 |
|
|
neorv32_pwm_setup(CLK_PRSC_64);
|
| 91 |
|
|
|
| 92 |
|
|
|
| 93 |
|
|
uint8_t pwm = 0;
|
| 94 |
|
|
uint8_t up = 1;
|
| 95 |
|
|
uint8_t ch = 0;
|
| 96 |
|
|
|
| 97 |
|
|
// animate!
|
| 98 |
|
|
while(1) {
|
| 99 |
|
|
|
| 100 |
|
|
// update duty cycle
|
| 101 |
|
|
if (up) {
|
| 102 |
|
|
if (pwm == (PWM_MAX & 0xFF)) {
|
| 103 |
|
|
up = 0;
|
| 104 |
|
|
}
|
| 105 |
|
|
else {
|
| 106 |
|
|
pwm++;
|
| 107 |
|
|
}
|
| 108 |
|
|
}
|
| 109 |
|
|
else {
|
| 110 |
|
|
if (pwm == 0) {
|
| 111 |
|
|
ch = (ch + 1) & 3; // goto next channel
|
| 112 |
|
|
up = 1;
|
| 113 |
|
|
}
|
| 114 |
|
|
else {
|
| 115 |
|
|
pwm--;
|
| 116 |
|
|
}
|
| 117 |
|
|
}
|
| 118 |
|
|
|
| 119 |
|
|
// output new duty cycle
|
| 120 |
|
|
if (ch != 3) { // skip channel 3
|
| 121 |
|
|
neorv32_pwm_set(ch, pwm);
|
| 122 |
|
|
}
|
| 123 |
|
|
|
| 124 |
34 |
zero_gravi |
neorv32_cpu_delay_ms(10); // wait ~10ms
|
| 125 |
2 |
zero_gravi |
}
|
| 126 |
|
|
|
| 127 |
|
|
return 0;
|
| 128 |
|
|
}
|
