From 67baec472de1fb7ee6db2781278480e10ed30f24 Mon Sep 17 00:00:00 2001 From: Jacob Rosenthal Date: Thu, 11 Nov 2021 23:27:03 -0700 Subject: [PATCH] nrf: dump the pwm_sequence example for clarity It is basically impossible to directly convert that example to a sequence for various reasons. You cant have multiple channels on same buffer with one sequence instance for starters, also at that clock rate and max_duty 1 period is far longer than the 3ms it was using, which would require using a new max_duty and thus require regenerating the sine table which makes it not representitive of the original example anymore --- examples/nrf/src/bin/pwm_led.rs | 47 -------------- examples/nrf/src/bin/pwm_sequence.rs | 91 +++------------------------- 2 files changed, 9 insertions(+), 129 deletions(-) delete mode 100644 examples/nrf/src/bin/pwm_led.rs diff --git a/examples/nrf/src/bin/pwm_led.rs b/examples/nrf/src/bin/pwm_led.rs deleted file mode 100644 index d0b71a5c..00000000 --- a/examples/nrf/src/bin/pwm_led.rs +++ /dev/null @@ -1,47 +0,0 @@ -#![no_std] -#![no_main] -#![feature(type_alias_impl_trait)] - -#[path = "../example_common.rs"] -mod example_common; -use defmt::*; -use embassy::executor::Spawner; -use embassy::time::{Duration, Timer}; -use embassy_nrf::gpio::NoPin; -use embassy_nrf::pwm::{Prescaler, SimplePwm}; -use embassy_nrf::Peripherals; - -#[embassy::main] -async fn main(_spawner: Spawner, p: Peripherals) { - let mut pwm = SimplePwm::new(p.PWM0, p.P0_13, NoPin, NoPin, NoPin); - // set_period doesnt actually set what you give it, because it only has a - // few options from the hardhware so be explicit instead - // Div128 is slowest, 125khz still crazy fast for our eyes - pwm.set_prescaler(Prescaler::Div128); - - info!("pwm initialized!"); - - // default max_duty if not specified is 1000 - // so 0 would be fully off and 1000 or above would be fully on - loop { - info!("100%"); - pwm.set_duty(0, 1000); - Timer::after(Duration::from_millis(5000)).await; - - info!("25%"); - pwm.set_duty(0, 250); - Timer::after(Duration::from_millis(5000)).await; - - info!("10%"); - pwm.set_duty(0, 100); - Timer::after(Duration::from_millis(5000)).await; - - info!("5%"); - pwm.set_duty(0, 50); - Timer::after(Duration::from_millis(5000)).await; - - info!("0%"); - pwm.set_duty(0, 0); - Timer::after(Duration::from_millis(5000)).await; - } -} diff --git a/examples/nrf/src/bin/pwm_sequence.rs b/examples/nrf/src/bin/pwm_sequence.rs index 6014c899..1e15bf6c 100644 --- a/examples/nrf/src/bin/pwm_sequence.rs +++ b/examples/nrf/src/bin/pwm_sequence.rs @@ -13,89 +13,15 @@ use embassy_nrf::Peripherals; #[embassy::main] async fn main(_spawner: Spawner, p: Peripherals) { - // for i in range(1024): print(int((math.sin(i/512*math.pi)*0.4+0.5)**2*32767), ', ', end='') - let seq_values: [u16; 1024] = [ - 8191, 8272, 8353, 8434, 8516, 8598, 8681, 8764, 8847, 8931, 9015, 9099, 9184, 9269, 9354, - 9440, 9526, 9613, 9700, 9787, 9874, 9962, 10050, 10139, 10227, 10316, 10406, 10495, 10585, - 10675, 10766, 10857, 10948, 11039, 11131, 11223, 11315, 11407, 11500, 11592, 11685, 11779, - 11872, 11966, 12060, 12154, 12248, 12343, 12438, 12533, 12628, 12723, 12818, 12914, 13010, - 13106, 13202, 13298, 13394, 13491, 13587, 13684, 13781, 13878, 13975, 14072, 14169, 14266, - 14364, 14461, 14558, 14656, 14754, 14851, 14949, 15046, 15144, 15242, 15339, 15437, 15535, - 15632, 15730, 15828, 15925, 16023, 16120, 16218, 16315, 16412, 16510, 16607, 16704, 16801, - 16898, 16995, 17091, 17188, 17284, 17380, 17477, 17572, 17668, 17764, 17859, 17955, 18050, - 18145, 18239, 18334, 18428, 18522, 18616, 18710, 18803, 18896, 18989, 19082, 19174, 19266, - 19358, 19449, 19540, 19631, 19722, 19812, 19902, 19991, 20081, 20169, 20258, 20346, 20434, - 20521, 20608, 20695, 20781, 20867, 20952, 21037, 21122, 21206, 21290, 21373, 21456, 21538, - 21620, 21701, 21782, 21863, 21943, 22022, 22101, 22179, 22257, 22335, 22412, 22488, 22564, - 22639, 22714, 22788, 22861, 22934, 23007, 23079, 23150, 23220, 23290, 23360, 23429, 23497, - 23564, 23631, 23698, 23763, 23828, 23892, 23956, 24019, 24081, 24143, 24204, 24264, 24324, - 24383, 24441, 24499, 24555, 24611, 24667, 24721, 24775, 24828, 24881, 24933, 24983, 25034, - 25083, 25132, 25180, 25227, 25273, 25319, 25363, 25407, 25451, 25493, 25535, 25575, 25615, - 25655, 25693, 25731, 25767, 25803, 25838, 25873, 25906, 25939, 25971, 26002, 26032, 26061, - 26089, 26117, 26144, 26170, 26195, 26219, 26242, 26264, 26286, 26307, 26327, 26346, 26364, - 26381, 26397, 26413, 26427, 26441, 26454, 26466, 26477, 26487, 26496, 26505, 26512, 26519, - 26525, 26530, 26534, 26537, 26539, 26540, 26541, 26540, 26539, 26537, 26534, 26530, 26525, - 26519, 26512, 26505, 26496, 26487, 26477, 26466, 26454, 26441, 26427, 26413, 26397, 26381, - 26364, 26346, 26327, 26307, 26286, 26264, 26242, 26219, 26195, 26170, 26144, 26117, 26089, - 26061, 26032, 26002, 25971, 25939, 25906, 25873, 25838, 25803, 25767, 25731, 25693, 25655, - 25615, 25575, 25535, 25493, 25451, 25407, 25363, 25319, 25273, 25227, 25180, 25132, 25083, - 25034, 24983, 24933, 24881, 24828, 24775, 24721, 24667, 24611, 24555, 24499, 24441, 24383, - 24324, 24264, 24204, 24143, 24081, 24019, 23956, 23892, 23828, 23763, 23698, 23631, 23564, - 23497, 23429, 23360, 23290, 23220, 23150, 23079, 23007, 22934, 22861, 22788, 22714, 22639, - 22564, 22488, 22412, 22335, 22257, 22179, 22101, 22022, 21943, 21863, 21782, 21701, 21620, - 21538, 21456, 21373, 21290, 21206, 21122, 21037, 20952, 20867, 20781, 20695, 20608, 20521, - 20434, 20346, 20258, 20169, 20081, 19991, 19902, 19812, 19722, 19631, 19540, 19449, 19358, - 19266, 19174, 19082, 18989, 18896, 18803, 18710, 18616, 18522, 18428, 18334, 18239, 18145, - 18050, 17955, 17859, 17764, 17668, 17572, 17477, 17380, 17284, 17188, 17091, 16995, 16898, - 16801, 16704, 16607, 16510, 16412, 16315, 16218, 16120, 16023, 15925, 15828, 15730, 15632, - 15535, 15437, 15339, 15242, 15144, 15046, 14949, 14851, 14754, 14656, 14558, 14461, 14364, - 14266, 14169, 14072, 13975, 13878, 13781, 13684, 13587, 13491, 13394, 13298, 13202, 13106, - 13010, 12914, 12818, 12723, 12628, 12533, 12438, 12343, 12248, 12154, 12060, 11966, 11872, - 11779, 11685, 11592, 11500, 11407, 11315, 11223, 11131, 11039, 10948, 10857, 10766, 10675, - 10585, 10495, 10406, 10316, 10227, 10139, 10050, 9962, 9874, 9787, 9700, 9613, 9526, 9440, - 9354, 9269, 9184, 9099, 9015, 8931, 8847, 8764, 8681, 8598, 8516, 8434, 8353, 8272, 8191, - 8111, 8031, 7952, 7873, 7794, 7716, 7638, 7561, 7484, 7407, 7331, 7255, 7180, 7105, 7031, - 6957, 6883, 6810, 6738, 6665, 6594, 6522, 6451, 6381, 6311, 6241, 6172, 6104, 6036, 5968, - 5901, 5834, 5767, 5702, 5636, 5571, 5507, 5443, 5379, 5316, 5253, 5191, 5130, 5068, 5008, - 4947, 4888, 4828, 4769, 4711, 4653, 4596, 4539, 4482, 4426, 4371, 4316, 4261, 4207, 4153, - 4100, 4047, 3995, 3943, 3892, 3841, 3791, 3741, 3691, 3642, 3594, 3546, 3498, 3451, 3404, - 3358, 3312, 3267, 3222, 3178, 3134, 3090, 3047, 3005, 2962, 2921, 2879, 2839, 2798, 2758, - 2719, 2680, 2641, 2603, 2565, 2528, 2491, 2454, 2418, 2382, 2347, 2312, 2278, 2244, 2210, - 2177, 2144, 2112, 2080, 2048, 2017, 1986, 1956, 1926, 1896, 1867, 1838, 1810, 1781, 1754, - 1726, 1699, 1673, 1646, 1620, 1595, 1570, 1545, 1520, 1496, 1472, 1449, 1426, 1403, 1380, - 1358, 1336, 1315, 1294, 1273, 1252, 1232, 1212, 1192, 1173, 1154, 1135, 1117, 1099, 1081, - 1063, 1046, 1029, 1012, 996, 980, 964, 948, 933, 918, 903, 888, 874, 860, 846, 833, 819, - 806, 793, 781, 768, 756, 744, 733, 721, 710, 699, 688, 677, 667, 657, 647, 637, 627, 618, - 609, 599, 591, 582, 574, 565, 557, 549, 541, 534, 526, 519, 512, 505, 498, 492, 485, 479, - 473, 467, 461, 455, 450, 444, 439, 434, 429, 424, 419, 415, 410, 406, 402, 398, 394, 390, - 386, 383, 379, 376, 373, 370, 367, 364, 361, 359, 356, 354, 351, 349, 347, 345, 343, 342, - 340, 338, 337, 336, 334, 333, 332, 331, 330, 330, 329, 328, 328, 328, 327, 327, 327, 327, - 327, 328, 328, 328, 329, 330, 330, 331, 332, 333, 334, 336, 337, 338, 340, 342, 343, 345, - 347, 349, 351, 354, 356, 359, 361, 364, 367, 370, 373, 376, 379, 383, 386, 390, 394, 398, - 402, 406, 410, 415, 419, 424, 429, 434, 439, 444, 450, 455, 461, 467, 473, 479, 485, 492, - 498, 505, 512, 519, 526, 534, 541, 549, 557, 565, 574, 582, 591, 599, 609, 618, 627, 637, - 647, 657, 667, 677, 688, 699, 710, 721, 733, 744, 756, 768, 781, 793, 806, 819, 833, 846, - 860, 874, 888, 903, 918, 933, 948, 964, 980, 996, 1012, 1029, 1046, 1063, 1081, 1099, 1117, - 1135, 1154, 1173, 1192, 1212, 1232, 1252, 1273, 1294, 1315, 1336, 1358, 1380, 1403, 1426, - 1449, 1472, 1496, 1520, 1545, 1570, 1595, 1620, 1646, 1673, 1699, 1726, 1754, 1781, 1810, - 1838, 1867, 1896, 1926, 1956, 1986, 2017, 2048, 2080, 2112, 2144, 2177, 2210, 2244, 2278, - 2312, 2347, 2382, 2418, 2454, 2491, 2528, 2565, 2603, 2641, 2680, 2719, 2758, 2798, 2839, - 2879, 2921, 2962, 3005, 3047, 3090, 3134, 3178, 3222, 3267, 3312, 3358, 3404, 3451, 3498, - 3546, 3594, 3642, 3691, 3741, 3791, 3841, 3892, 3943, 3995, 4047, 4100, 4153, 4207, 4261, - 4316, 4371, 4426, 4482, 4539, 4596, 4653, 4711, 4769, 4828, 4888, 4947, 5008, 5068, 5130, - 5191, 5253, 5316, 5379, 5443, 5507, 5571, 5636, 5702, 5767, 5834, 5901, 5968, 6036, 6104, - 6172, 6241, 6311, 6381, 6451, 6522, 6594, 6665, 6738, 6810, 6883, 6957, 7031, 7105, 7180, - 7255, 7331, 7407, 7484, 7561, 7638, 7716, 7794, 7873, 7952, 8031, 8111, - ]; + let seq_values: [u16; 5] = [1000, 250, 100, 50, 0]; let mut config = SequenceConfig::default(); - config.prescaler = Prescaler::Div1; - // 1 period is 32767 * 1/16mhz = 0.002047938 = 2.047938ms - config.max_duty = 32767; - // pwm example is delaying >~3ms before updating duty cycle, our refreshes - // happen exactly at 2.047938ms so we need a delay after each value of >~1ms - // which for us is ~1-2 periods - config.refresh = 3; + config.prescaler = Prescaler::Div128; + // 1 period is 1000 * (128/16mhz = 0.000008s = 0.008ms) = 8ms + // but say we want to hold the value for 5000ms + // so we want to repeat our value as many times as necessary until 5000ms passes + // want 5000/8 = 625 periods total to occur, so 624 (we get the one period for free remember) + config.refresh = 624; let pwm = unwrap!(SequencePwm::new( p.PWM0, @@ -107,9 +33,10 @@ async fn main(_spawner: Spawner, p: Peripherals) { &seq_values )); let _ = pwm.start(SequenceMode::Infinite); + info!("pwm started!"); loop { - Timer::after(Duration::from_millis(1000)).await; + Timer::after(Duration::from_millis(5000)).await; } }