nodemcu-firmware/app/modules/tm1829.c

114 lines
3.0 KiB
C

#include "module.h"
#include "lauxlib.h"
#include "platform.h"
#include "c_stdlib.h"
#include "c_string.h"
#include "user_interface.h"
static inline uint32_t _getCycleCount(void) {
uint32_t cycles;
__asm__ __volatile__("rsr %0,ccount":"=a" (cycles));
return cycles;
}
// This algorithm reads the cpu clock cycles to calculate the correct
// pulse widths. It works in both 80 and 160 MHz mode.
static void ICACHE_RAM_ATTR tm1829_write_to_pin(uint8_t pin, uint8_t *pixels, uint32_t length) {
uint8_t *p, *end;
p = pixels;
end = p + length;
const uint32_t t0l = (1000 * system_get_cpu_freq()) / 3333; // 0.390us (spec=0.35 +- 0.15)
const uint32_t t1l = (1000 * system_get_cpu_freq()) / 1250; // 0.800us (spec=0.70 +- 0.15)
const uint32_t ttot = (1000 * system_get_cpu_freq()) / 800; // 1.25us
while (p != end) {
register int i;
register uint8_t pixel = *p++;
ets_intr_lock();
for (i = 7; i >= 0; i--) {
register uint32_t pin_mask = 1 << pin;
// Select low time
register uint32_t tl = ((pixel >> i) & 1) ? t1l : t0l;
register uint32_t t1, t2;
register uint32_t t = _getCycleCount();
t1 = t + tl;
t2 = t + ttot;
GPIO_REG_WRITE(GPIO_OUT_W1TC_ADDRESS, pin_mask); // Set pin low
while (_getCycleCount() < t1);
GPIO_REG_WRITE(GPIO_OUT_W1TS_ADDRESS, pin_mask); // Set pin high
while (_getCycleCount() < t2);
}
ets_intr_unlock();
}
}
// Lua: tm1829.write(pin, "string")
// Byte triples in the string are interpreted as R G B values and sent to the hardware as G R B.
// WARNING: this function scrambles the input buffer :
// a = string.char(255,0,128)
// tm1829.write(3,a)
// =a.byte()
// (0,255,128)
static int ICACHE_FLASH_ATTR tm1829_write(lua_State* L)
{
const uint8_t pin = luaL_checkinteger(L, 1);
size_t length;
const char *rgb = luaL_checklstring(L, 2, &length);
// dont modify lua-internal lstring - make a copy instead
char *buffer = (char *)c_malloc(length);
// Ignore incomplete Byte triples at the end of buffer
length -= length % 3;
// Copy payload and make sure first byte is < 0xFF (triggers
// constant current command, instead of PWM duty command)
size_t i;
for (i = 0; i < length; i += 3) {
buffer[i] = rgb[i];
buffer[i + 1] = rgb[i + 1];
buffer[i + 2] = rgb[i + 2];
// Check for first byte
if (buffer[i] == 0xff)
buffer[i] = 0xfe;
}
// Initialize the output pin and wait a bit
platform_gpio_mode(pin, PLATFORM_GPIO_OUTPUT, PLATFORM_GPIO_FLOAT);
platform_gpio_write(pin, 1);
// Send the buffer
tm1829_write_to_pin(pin_num[pin], (uint8_t*) buffer, length);
os_delay_us(500); // reset time
c_free(buffer);
return 0;
}
LROT_BEGIN(tm1829)
LROT_FUNCENTRY( write, tm1829_write )
LROT_END( tm1829, NULL, 0 )
int luaopen_tm1829(lua_State *L) {
// TODO: Make sure that the GPIO system is initialized
return 0;
}
NODEMCU_MODULE(TM1829, "tm1829", tm1829, luaopen_tm1829);