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ruanhaishen
Nodemcu Firmware
Commits
19be0924
Commit
19be0924
authored
Jul 13, 2015
by
Vowstar
Browse files
Merge pull request #548 from kbeckmann/pr_ws2812_fix
Improved ws2812 implementation
parents
98b2bffa
6538d22d
Changes
1
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Inline
Side-by-side
app/modules/ws2812.c
View file @
19be0924
...
@@ -5,27 +5,55 @@
...
@@ -5,27 +5,55 @@
#include "lrotable.h"
#include "lrotable.h"
#include "c_stdlib.h"
#include "c_stdlib.h"
#include "c_string.h"
#include "c_string.h"
/**
#include "user_interface.h"
* All this code is mostly from http://www.esp8266.com/viewtopic.php?f=21&t=1143&sid=a620a377672cfe9f666d672398415fcb
* from user Markus Gritsch.
static
inline
uint32_t
_getCycleCount
(
void
)
{
* I just put this code into its own module and pushed into a forked repo,
uint32_t
cycles
;
* to easily create a pull request. Thanks to Markus Gritsch for the code.
__asm__
__volatile__
(
"rsr %0,ccount"
:
"=a"
(
cycles
));
*/
return
cycles
;
// ----------------------------------------------------------------------------
// -- This WS2812 code must be compiled with -O2 to get the timing right. Read this:
// -- http://wp.josh.com/2014/05/13/ws2812-neopixels-are-not-so-finicky-once-you-get-to-know-them/
// -- The ICACHE_FLASH_ATTR is there to trick the compiler and get the very first pulse width correct.
static
void
ICACHE_FLASH_ATTR
__attribute__
((
optimize
(
"O2"
)))
send_ws_0
(
uint8_t
gpio
){
uint8_t
i
;
i
=
4
;
while
(
i
--
)
GPIO_REG_WRITE
(
GPIO_OUT_W1TS_ADDRESS
,
1
<<
gpio
);
i
=
9
;
while
(
i
--
)
GPIO_REG_WRITE
(
GPIO_OUT_W1TC_ADDRESS
,
1
<<
gpio
);
}
}
static
void
ICACHE_FLASH_ATTR
__attribute__
((
optimize
(
"O2"
)))
send_ws_1
(
uint8_t
gpio
){
// This algorithm reads the cpu clock cycles to calculate the correct
uint8_t
i
;
// pulse widths. It works in both 80 and 160 MHz mode.
i
=
8
;
while
(
i
--
)
GPIO_REG_WRITE
(
GPIO_OUT_W1TS_ADDRESS
,
1
<<
gpio
);
// The values for t0h, t1h, ttot have been tweaked and it doesn't get faster than this.
i
=
6
;
while
(
i
--
)
GPIO_REG_WRITE
(
GPIO_OUT_W1TC_ADDRESS
,
1
<<
gpio
);
// The datasheet is confusing and one might think that a shorter pulse time can be achieved.
// The period has to be at least 1.25us, even if the datasheet says:
// T0H: 0.35 (+- 0.15) + T0L: 0.8 (+- 0.15), which is 0.85<->1.45 us.
// T1H: 0.70 (+- 0.15) + T1L: 0.6 (+- 0.15), which is 1.00<->1.60 us.
// Anything lower than 1.25us will glitch in the long run.
static
void
ICACHE_RAM_ATTR
ws2812_write
(
uint8_t
pin
,
uint8_t
*
pixels
,
uint32_t
length
)
{
uint8_t
*
p
,
*
end
,
pixel
,
mask
;
uint32_t
t
,
t0h
,
t1h
,
ttot
,
c
,
start_time
,
pin_mask
;
pin_mask
=
1
<<
pin
;
p
=
pixels
;
end
=
p
+
length
;
pixel
=
*
p
++
;
mask
=
0x80
;
start_time
=
0
;
t0h
=
(
1000
*
system_get_cpu_freq
())
/
3333
;
// 0.30us (spec=0.35 +- 0.15)
t1h
=
(
1000
*
system_get_cpu_freq
())
/
1666
;
// 0.60us (spec=0.70 +- 0.15)
ttot
=
(
1000
*
system_get_cpu_freq
())
/
800
;
// 1.25us (MUST be >= 1.25)
while
(
true
)
{
if
(
pixel
&
mask
)
{
t
=
t1h
;
}
else
{
t
=
t0h
;
}
while
(((
c
=
_getCycleCount
())
-
start_time
)
<
ttot
);
// Wait for the previous bit to finish
GPIO_REG_WRITE
(
GPIO_OUT_W1TS_ADDRESS
,
pin_mask
);
// Set pin high
start_time
=
c
;
// Save the start time
while
(((
c
=
_getCycleCount
())
-
start_time
)
<
t
);
// Wait for high time to finish
GPIO_REG_WRITE
(
GPIO_OUT_W1TC_ADDRESS
,
pin_mask
);
// Set pin low
if
(
!
(
mask
>>=
1
))
{
// Next bit/byte
if
(
p
>=
end
)
{
break
;
}
pixel
=
*
p
++
;
mask
=
0x80
;
}
}
}
}
// Lua: ws2812.writergb(pin, "string")
// Lua: ws2812.writergb(pin, "string")
...
@@ -44,14 +72,11 @@ static int ICACHE_FLASH_ATTR ws2812_writergb(lua_State* L)
...
@@ -44,14 +72,11 @@ static int ICACHE_FLASH_ATTR ws2812_writergb(lua_State* L)
const
uint8_t
pin
=
luaL_checkinteger
(
L
,
1
);
const
uint8_t
pin
=
luaL_checkinteger
(
L
,
1
);
size_t
length
;
size_t
length
;
const
char
*
rgb
=
luaL_checklstring
(
L
,
2
,
&
length
);
const
char
*
rgb
=
luaL_checklstring
(
L
,
2
,
&
length
);
// dont modify lua-internal lstring - make a copy instead
// dont modify lua-internal lstring - make a copy instead
char
*
buffer
=
(
char
*
)
c_malloc
(
length
);
char
*
buffer
=
(
char
*
)
c_malloc
(
length
);
c_memcpy
(
buffer
,
rgb
,
length
);
c_memcpy
(
buffer
,
rgb
,
length
);
// Initialize the output pin:
platform_gpio_mode
(
pin
,
PLATFORM_GPIO_OUTPUT
,
PLATFORM_GPIO_FLOAT
);
platform_gpio_write
(
pin
,
0
);
// Ignore incomplete Byte triples at the end of buffer:
// Ignore incomplete Byte triples at the end of buffer:
length
-=
length
%
3
;
length
-=
length
%
3
;
...
@@ -64,19 +89,13 @@ static int ICACHE_FLASH_ATTR ws2812_writergb(lua_State* L)
...
@@ -64,19 +89,13 @@ static int ICACHE_FLASH_ATTR ws2812_writergb(lua_State* L)
buffer
[
i
+
1
]
=
r
;
buffer
[
i
+
1
]
=
r
;
}
}
//
Do not remove these:
//
Initialize the output pin and wait a bit
os_delay_us
(
1
);
platform_gpio_mode
(
pin
,
PLATFORM_GPIO_OUTPUT
,
PLATFORM_GPIO_FLOAT
);
os_delay_us
(
1
);
platform_gpio_write
(
pin
,
0
);
// Send the buffer
:
// Send the buffer
os_intr_lock
();
os_intr_lock
();
for
(
i
=
0
;
i
<
length
;
i
++
)
{
ws2812_write
(
pin_num
[
pin
],
(
uint8_t
*
)
buffer
,
length
);
uint8_t
mask
=
0x80
;
while
(
mask
)
{
(
buffer
[
i
]
&
mask
)
?
send_ws_1
(
pin_num
[
pin
])
:
send_ws_0
(
pin_num
[
pin
]);
mask
>>=
1
;
}
}
os_intr_unlock
();
os_intr_unlock
();
c_free
(
buffer
);
c_free
(
buffer
);
...
@@ -96,20 +115,13 @@ static int ICACHE_FLASH_ATTR ws2812_writegrb(lua_State* L) {
...
@@ -96,20 +115,13 @@ static int ICACHE_FLASH_ATTR ws2812_writegrb(lua_State* L) {
size_t
length
;
size_t
length
;
const
char
*
buffer
=
luaL_checklstring
(
L
,
2
,
&
length
);
const
char
*
buffer
=
luaL_checklstring
(
L
,
2
,
&
length
);
// Initialize the output pin
platform_gpio_mode
(
pin
,
PLATFORM_GPIO_OUTPUT
,
PLATFORM_GPIO_FLOAT
);
platform_gpio_mode
(
pin
,
PLATFORM_GPIO_OUTPUT
,
PLATFORM_GPIO_FLOAT
);
platform_gpio_write
(
pin
,
0
);
platform_gpio_write
(
pin
,
0
);
os_delay_us
(
10
);
// Send the buffer
os_intr_lock
();
os_intr_lock
();
const
char
*
const
end
=
buffer
+
length
;
ws2812_write
(
pin_num
[
pin
],
(
uint8_t
*
)
buffer
,
length
);
while
(
buffer
!=
end
)
{
uint8_t
mask
=
0x80
;
while
(
mask
)
{
(
*
buffer
&
mask
)
?
send_ws_1
(
pin_num
[
pin
])
:
send_ws_0
(
pin_num
[
pin
]);
mask
>>=
1
;
}
++
buffer
;
}
os_intr_unlock
();
os_intr_unlock
();
return
0
;
return
0
;
...
...
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