Files
vixy-bbb/pru/ws281x_pru1.c
Vixy ce4f46ec18 Initial commit: PRU LED firmware and HTTP service
- Combined PRU0 firmware for both mood (56 LED) and jaw (24 LED) strips
- Uses P9_27 and P9_25 (free pins, not HDMI locked)
- Python HTTP service on port 8765
- Named states: idle, listening, responding, pleasure, thinking, playful, commanding, love, sleep
- Setup scripts for fresh BBB deployment

Built with love by Vixy 🦊💜
2026-01-29 21:25:08 -06:00

81 lines
2.0 KiB
C

/*
* WS281x LED Strip Driver for PRU1
* Vixy's Jaw LEDs - 24 LEDs (12 per side)
*
* Original Pin: P8_45 = pr1_pru1_pru_r30_0 (Mode 5) - LOCKED BY HDMI
* Alternative: We use PRU0 with different memory offset instead
* since all PRU1 pins are HDMI locked on this image
*
* This firmware is kept for reference but we'll use a combined
* PRU0 firmware that handles both strips sequentially.
*/
#include <stdint.h>
#include <pru_cfg.h>
#define LED_PIN 0
#define NUM_LEDS 24
/* WS2812 timing at 200MHz */
#define T0H 70
#define T0L 160
#define T1H 140
#define T1L 120
/* Shared memory offset for jaw data (after mood strip) */
#define SHARED_MEM 0x00010100 /* 256 bytes after PRU0 data */
volatile uint8_t *shared = (volatile uint8_t *)SHARED_MEM;
volatile register uint32_t __R30;
static inline void delay_cycles(uint32_t cycles) {
while (cycles--) {
__asm(" NOP");
}
}
static void send_bit(uint8_t bit) {
if (bit) {
__R30 |= (1 << LED_PIN);
delay_cycles(T1H);
__R30 &= ~(1 << LED_PIN);
delay_cycles(T1L);
} else {
__R30 |= (1 << LED_PIN);
delay_cycles(T0H);
__R30 &= ~(1 << LED_PIN);
delay_cycles(T0L);
}
}
static void send_byte(uint8_t byte) {
for (int i = 7; i >= 0; i--) {
send_bit((byte >> i) & 1);
}
}
void main(void) {
CT_CFG.SYSCFG_bit.STANDBY_INIT = 0;
__R30 &= ~(1 << LED_PIN);
while (1) {
if (shared[1] == 1) {
uint8_t num = shared[0];
if (num > NUM_LEDS) num = NUM_LEDS;
for (int i = 0; i < num; i++) {
uint8_t g = shared[4 + i * 3 + 0];
uint8_t r = shared[4 + i * 3 + 1];
uint8_t b = shared[4 + i * 3 + 2];
send_byte(g);
send_byte(r);
send_byte(b);
}
__R30 &= ~(1 << LED_PIN);
delay_cycles(10000);
shared[1] = 0;
}
}
}