diff options
| author | Kevin O'Connor <kevin@koconnor.net> | 2025-04-17 13:06:22 -0400 |
|---|---|---|
| committer | Kevin O'Connor <kevin@koconnor.net> | 2025-04-17 13:06:22 -0400 |
| commit | 413ff19ea8e0e5e09c0233225ffa8ad07b1233d6 (patch) | |
| tree | e18ca12eaf68e21d4e332484a85332dd993e76ae /src/neopixel.c | |
| parent | 4e7fcc27040da2ae72bf44b445a97bf9a981dd98 (diff) | |
| download | kutter-413ff19ea8e0e5e09c0233225ffa8ad07b1233d6.tar.gz kutter-413ff19ea8e0e5e09c0233225ffa8ad07b1233d6.tar.xz kutter-413ff19ea8e0e5e09c0233225ffa8ad07b1233d6.zip | |
neopixel: Add comments on timing
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Diffstat (limited to 'src/neopixel.c')
| -rw-r--r-- | src/neopixel.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/src/neopixel.c b/src/neopixel.c index e7890a06..4e171658 100644 --- a/src/neopixel.c +++ b/src/neopixel.c @@ -1,6 +1,6 @@ // Support for bit-banging commands to WS2812 type "neopixel" LEDs // -// Copyright (C) 2019 Kevin O'Connor <kevin@koconnor.net> +// Copyright (C) 2019-2025 Kevin O'Connor <kevin@koconnor.net> // // This file may be distributed under the terms of the GNU GPLv3 license. @@ -74,8 +74,11 @@ neopixel_delay(neopixel_time_t start, neopixel_time_t ticks) #endif +// Minimum amount of time for a '1 bit' to be reliably detected #define PULSE_LONG_TICKS nsecs_to_ticks(650) -#define PULSE_SHORT_TICKS nsecs_to_ticks(200) +// Minimum amount of time for any level change to be reliably detected +#define EDGE_MIN_TICKS nsecs_to_ticks(200) +// Minimum average time needed to transmit each bit (two level changes) #define BIT_MIN_TICKS nsecs_to_ticks(1250) @@ -147,14 +150,14 @@ send_data(struct neopixel_s *n) gpio_out_toggle_noirq(pin); irq_enable(); - neopixel_delay(neopixel_get_time(), PULSE_SHORT_TICKS); + neopixel_delay(neopixel_get_time(), EDGE_MIN_TICKS); } else { // Short pulse neopixel_delay(last_start, BIT_MIN_TICKS); irq_disable(); neopixel_time_t start = neopixel_get_time(); gpio_out_toggle_noirq(pin); - neopixel_delay(start, PULSE_SHORT_TICKS); + neopixel_delay(start, EDGE_MIN_TICKS); gpio_out_toggle_noirq(pin); irq_enable(); |