nodemcu-firmware/app/modules/ws2812.c

280 lines
8.0 KiB
C

#include "module.h"
#include "lauxlib.h"
#include "lmem.h"
#include "platform.h"
#include "c_stdlib.h"
#include "c_string.h"
#include "user_interface.h"
#include "driver/uart.h"
#define CANARY_VALUE 0x32383132
typedef struct {
int canary;
int size;
uint8_t colorsPerLed;
uint8_t values[0];
} ws2812_buffer;
// Init UART1 to be able to stream WS2812 data
// We use GPIO2 as output pin
static void ws2812_init() {
// Configure UART1
// Set baudrate of UART1 to 3200000
WRITE_PERI_REG(UART_CLKDIV(1), UART_CLK_FREQ / 3200000);
// Set UART Configuration No parity / 6 DataBits / 1 StopBits / Invert TX
WRITE_PERI_REG(UART_CONF0(1), UART_TXD_INV | (1 << UART_STOP_BIT_NUM_S) | (1 << UART_BIT_NUM_S));
// Pull GPIO2 down
platform_gpio_mode(4, PLATFORM_GPIO_OUTPUT, PLATFORM_GPIO_FLOAT);
platform_gpio_write(4, 0);
// Waits 10us to simulate a reset
os_delay_us(10);
// Redirect UART1 to GPIO2
// Disable GPIO2
GPIO_REG_WRITE(GPIO_ENABLE_W1TC_ADDRESS, BIT2);
// Enable Function 2 for GPIO2 (U1TXD)
PIN_FUNC_SELECT(PERIPHS_IO_MUX_GPIO2_U, FUNC_U1TXD_BK);
}
// Stream data using UART1 routed to GPIO2
// ws2812.init() should be called first
//
// NODE_DEBUG should not be activated because it also uses UART1
static void ICACHE_RAM_ATTR ws2812_write(uint8_t *pixels, uint32_t length) {
// Data are sent LSB first, with a start bit at 0, an end bit at 1 and all inverted
// 0b00110111 => 110111 => [0]111011[1] => 10001000 => 00
// 0b00000111 => 000111 => [0]111000[1] => 10001110 => 01
// 0b00110100 => 110100 => [0]001011[1] => 11101000 => 10
// 0b00000100 => 000100 => [0]001000[1] => 11101110 => 11
// Array declared as static const to avoid runtime generation
// But declared in ".data" section to avoid read penalty from FLASH
static const __attribute__((section(".data._uartData"))) uint8_t _uartData[4] = { 0b00110111, 0b00000111, 0b00110100, 0b00000100 };
uint8_t *end = pixels + length;
do {
uint8_t value = *pixels++;
// Wait enough space in the FIFO buffer
// (Less than 124 bytes in the buffer)
while (((READ_PERI_REG(UART_STATUS(1)) >> UART_TXFIFO_CNT_S) & UART_TXFIFO_CNT) > 124);
// Fill the buffer
WRITE_PERI_REG(UART_FIFO(1), _uartData[(value >> 6) & 3]);
WRITE_PERI_REG(UART_FIFO(1), _uartData[(value >> 4) & 3]);
WRITE_PERI_REG(UART_FIFO(1), _uartData[(value >> 2) & 3]);
WRITE_PERI_REG(UART_FIFO(1), _uartData[(value >> 0) & 3]);
} while(pixels < end);
}
// Lua: ws2812.write("string")
// Byte triples in the string are interpreted as G R B values.
//
// ws2812.init() should be called first
//
// ws2812.write(string.char(0, 255, 0)) sets the first LED red.
// ws2812.write(string.char(0, 0, 255):rep(10)) sets ten LEDs blue.
// ws2812.write(string.char(255, 0, 0, 255, 255, 255)) first LED green, second LED white.
static int ws2812_writegrb(lua_State* L) {
size_t length;
const char *values = luaL_checklstring(L, 1, &length);
// Send the buffer
ws2812_write((uint8_t*) values, length);
return 0;
}
// Handle a buffer where we can store led values
static int ws2812_new_buffer(lua_State *L) {
const int leds = luaL_checkint(L, 1);
const int colorsPerLed = luaL_checkint(L, 2);
luaL_argcheck(L, leds > 0, 1, "should be a positive integer");
luaL_argcheck(L, colorsPerLed > 0, 2, "should be a positive integer");
// Allocate memory
size_t size = sizeof(ws2812_buffer) + colorsPerLed*leds*sizeof(uint8_t);
ws2812_buffer * buffer = (ws2812_buffer*)lua_newuserdata(L, size);
// Associate its metatable
luaL_getmetatable(L, "ws2812.buffer");
lua_setmetatable(L, -2);
// Save led strip size
buffer->size = leds;
buffer->colorsPerLed = colorsPerLed;
// Store canary for future type checks
buffer->canary = CANARY_VALUE;
return 1;
}
static int ws2812_buffer_fill(lua_State* L) {
ws2812_buffer * buffer = (ws2812_buffer*)lua_touserdata(L, 1);
luaL_argcheck(L, buffer && buffer->canary == CANARY_VALUE, 1, "ws2812.buffer expected");
// Grab colors
int i, j;
int * colors = luaM_malloc(L, buffer->colorsPerLed * sizeof(int));
for (i = 0; i < buffer->colorsPerLed; i++)
{
colors[i] = luaL_checkinteger(L, 2+i);
}
// Fill buffer
uint8_t * p = &buffer->values[0];
for(i = 0; i < buffer->size; i++)
{
for (j = 0; j < buffer->colorsPerLed; j++)
{
*p++ = colors[j];
}
}
// Free memory
luaM_free(L, colors);
return 0;
}
static int ws2812_buffer_fade(lua_State* L) {
ws2812_buffer * buffer = (ws2812_buffer*)lua_touserdata(L, 1);
const int fade = luaL_checkinteger(L, 2);
luaL_argcheck(L, buffer && buffer->canary == CANARY_VALUE, 1, "ws2812.buffer expected");
luaL_argcheck(L, fade > 0, 2, "fade value should be a strict positive number");
uint8_t * p = &buffer->values[0];
int i;
for(i = 0; i < buffer->size * buffer->colorsPerLed; i++)
{
*p++ /= fade;
}
return 0;
}
static int ws2812_buffer_get(lua_State* L) {
ws2812_buffer * buffer = (ws2812_buffer*)lua_touserdata(L, 1);
const int led = luaL_checkinteger(L, 2) - 1;
luaL_argcheck(L, buffer && buffer->canary == CANARY_VALUE, 1, "ws2812.buffer expected");
luaL_argcheck(L, led >= 0 && led < buffer->size, 2, "index out of range");
int i;
for (i = 0; i < buffer->colorsPerLed; i++)
{
lua_pushnumber(L, buffer->values[buffer->colorsPerLed*led+i]);
}
return buffer->colorsPerLed;
}
static int ws2812_buffer_set(lua_State* L) {
ws2812_buffer * buffer = (ws2812_buffer*)lua_touserdata(L, 1);
const int led = luaL_checkinteger(L, 2) - 1;
luaL_argcheck(L, buffer && buffer->canary == CANARY_VALUE, 1, "ws2812.buffer expected");
luaL_argcheck(L, led >= 0 && led < buffer->size, 2, "index out of range");
int type = lua_type(L, 3);
if(type == LUA_TTABLE)
{
int i;
for (i = 0; i < buffer->colorsPerLed; i++)
{
// Get value and push it on stack
lua_rawgeti(L, 3, i+1);
// Convert it as int and store them in buffer
buffer->values[buffer->colorsPerLed*led+i] = lua_tonumber(L, -1);
}
// Clean up the stack
lua_pop(L, buffer->colorsPerLed);
}
else if(type == LUA_TSTRING)
{
size_t len;
const char * buf = lua_tolstring(L, 3, &len);
// Overflow check
if( buffer->colorsPerLed*led + len > buffer->colorsPerLed*buffer->size )
{
return luaL_error(L, "string size will exceed strip length");
}
c_memcpy(&buffer->values[buffer->colorsPerLed*led], buf, len);
}
else
{
int i;
for (i = 0; i < buffer->colorsPerLed; i++)
{
buffer->values[buffer->colorsPerLed*led+i] = luaL_checkinteger(L, 3+i);
}
}
return 0;
}
static int ws2812_buffer_size(lua_State* L) {
ws2812_buffer * buffer = (ws2812_buffer*)lua_touserdata(L, 1);
luaL_argcheck(L, buffer && buffer->canary == CANARY_VALUE, 1, "ws2812.buffer expected");
lua_pushnumber(L, buffer->size);
return 1;
}
static int ws2812_buffer_write(lua_State* L) {
ws2812_buffer * buffer = (ws2812_buffer*)lua_touserdata(L, 1);
luaL_argcheck(L, buffer && buffer->canary == CANARY_VALUE, 1, "ws2812.buffer expected");
// Send the buffer
ws2812_write(buffer->values, buffer->colorsPerLed*buffer->size);
return 0;
}
static const LUA_REG_TYPE ws2812_buffer_map[] =
{
{ LSTRKEY( "fade" ), LFUNCVAL( ws2812_buffer_fade )},
{ LSTRKEY( "fill" ), LFUNCVAL( ws2812_buffer_fill )},
{ LSTRKEY( "get" ), LFUNCVAL( ws2812_buffer_get )},
{ LSTRKEY( "set" ), LFUNCVAL( ws2812_buffer_set )},
{ LSTRKEY( "size" ), LFUNCVAL( ws2812_buffer_size )},
{ LSTRKEY( "write" ), LFUNCVAL( ws2812_buffer_write )},
{ LSTRKEY( "__index" ), LROVAL ( ws2812_buffer_map )},
{ LNILKEY, LNILVAL}
};
static const LUA_REG_TYPE ws2812_map[] =
{
{ LSTRKEY( "write" ), LFUNCVAL( ws2812_writegrb )},
{ LSTRKEY( "newBuffer" ), LFUNCVAL( ws2812_new_buffer )},
{ LSTRKEY( "init" ), LFUNCVAL( ws2812_init )},
{ LNILKEY, LNILVAL}
};
int luaopen_ws2812(lua_State *L) {
// TODO: Make sure that the GPIO system is initialized
luaL_rometatable(L, "ws2812.buffer", (void *)ws2812_buffer_map); // create metatable for ws2812.buffer
return 0;
}
NODEMCU_MODULE(WS2812, "ws2812", ws2812_map, luaopen_ws2812);