From b040195d31df6ad759f16ea3456471897f55daa1 Mon Sep 17 00:00:00 2001 From: Josh Rahm Date: Tue, 24 Nov 2020 13:43:58 -0700 Subject: add 2.5collatz to git before I delete it. --- 02.5-collatz/src/spin.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) create mode 100644 02.5-collatz/src/spin.c (limited to '02.5-collatz/src/spin.c') diff --git a/02.5-collatz/src/spin.c b/02.5-collatz/src/spin.c new file mode 100644 index 0000000..fbd16b6 --- /dev/null +++ b/02.5-collatz/src/spin.c @@ -0,0 +1,49 @@ +#include "spin.h" +#include "delay.h" +#include "gpio.h" + +#define SHORT_DELAY 200000 +#define LONG_DELAY (SHORT_DELAY * 2) + +static void flash_bit( + uint32_t base, gpio_output_pin_t out_pin, + uint8_t bit /* 0 => 0, non-zero => 1 */) +{ + pin_on(out_pin); + if (bit) { + delay(base * 2); + } else { + delay(base); + } + pin_off(out_pin); + delay(base); +} + +void spin(uint32_t base, uint8_t c) +{ + uint8_t code; + __IO gpio_port_t* port_b = enable_gpio(GPIO_PORT_B); + gpio_output_pin_t pin3 = set_gpio_pin_output(port_b, PIN_3); + + for (;;) { + code = c; + flash_bit(base, pin3, code & 0x80); + code <<= 1; + flash_bit(base, pin3, code & 0x80); + code <<= 1; + flash_bit(base, pin3, code & 0x80); + code <<= 1; + flash_bit(base, pin3, code & 0x80); + + code <<= 1; + flash_bit(base, pin3, code & 0x80); + code <<= 1; + flash_bit(base, pin3, code & 0x80); + code <<= 1; + flash_bit(base, pin3, code & 0x80); + code <<= 1; + flash_bit(base, pin3, code & 0x80); + + delay(base * 4); + } +} -- cgit