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zero_gravi |
// #################################################################################################
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// # < Use the PWM controller to modulate the GPIO output port > #
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// # ********************************************************************************************* #
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// # BSD 3-Clause License #
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// # #
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// # Copyright (c) 2020, Stephan Nolting. All rights reserved. #
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// # #
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// # Redistribution and use in source and binary forms, with or without modification, are #
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// # permitted provided that the following conditions are met: #
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// # #
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// # 1. Redistributions of source code must retain the above copyright notice, this list of #
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// # conditions and the following disclaimer. #
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// # #
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// # 2. Redistributions in binary form must reproduce the above copyright notice, this list of #
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// # conditions and the following disclaimer in the documentation and/or other materials #
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// # provided with the distribution. #
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// # #
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// # 3. Neither the name of the copyright holder nor the names of its contributors may be used to #
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// # endorse or promote products derived from this software without specific prior written #
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// # permission. #
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// # #
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// # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS #
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// # OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF #
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// # MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE #
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// # COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, #
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// # EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE #
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// # GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED #
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// # AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING #
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// # NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED #
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// # OF THE POSSIBILITY OF SUCH DAMAGE. #
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// # ********************************************************************************************* #
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// # The NEO430 Processor - https://github.com/stnolting/neo430 #
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// #################################################################################################
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// Libraries
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#include <stdint.h>
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#include <neo430.h>
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// Configuration
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#define BAUD_RATE 19200
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#define PWM_MAX 63
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/* ------------------------------------------------------------
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* INFO Main function
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* ------------------------------------------------------------ */
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int main(void) {
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// setup UART
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neo430_uart_setup(BAUD_RATE);
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neo430_uart_br_print("\n<<< PWM GPIO modulation demo >>>\n");
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// check if PWM unit was synthesized, exit if not
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if (!(SYS_FEATURES & (1<<SYS_PWM_EN))) {
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neo430_uart_br_print("Error! No PWM controller synthesized!");
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return 1;
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}
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// check if GPIO unit was synthesized, exit if not
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if (!(SYS_FEATURES & (1<<SYS_GPIO_EN))) {
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neo430_uart_br_print("Error! No GPIO controller synthesized!");
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return 1;
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}
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// enable pwm controller
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neo430_pwm_enable(PWM_PRSC_4, 1, 1); // 2nd highest frequency, 8-bit resolution, use GPIO modulation
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// clear GPIO output port
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neo430_gpio_port_set(0);
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// clear pwm channel 3 (GPIO PWM channel)
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neo430_pwm_set(0, 0);
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uint8_t pwm = 0;
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uint8_t up = 1;
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uint16_t cnt = 0;
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// animate!
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while(1) {
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// update duty cycle
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if (up) {
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if (pwm == (256/2)) // half max
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up = 0;
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else
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pwm++;
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}
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else {
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if (pwm == 0)
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up = 1;
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else
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pwm--;
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}
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// output new duty cycle
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neo430_pwm_set(3, pwm);
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// output simple counter on GPIO output port
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neo430_gpio_port_set((cnt>>4) & 0x00FF);
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cnt++;
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neo430_cpu_delay_ms(8);
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}
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return 0;
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}
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