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
commit ce4f46ec18
11 changed files with 714 additions and 0 deletions
--- a/pru/ws281x_pru0.c
+++ b/pru/ws281x_pru0.c
@@ -0,0 +1,94 @@
+/*
+ * WS281x LED Strip Driver for PRU0
+ * Vixy's Mood Strip - 56 LEDs
+ * 
+ * Pin: P8_11 = pr1_pru0_pru_r30_15 (Mode 6)
+ * Alternative: P9_27 = pr1_pru0_pru_r30_5 (Mode 5) - FREE PIN!
+ * 
+ * Shared Memory Layout (0x00010000):
+ *   [0]:     num_leds (max 56)
+ *   [1]:     trigger (write 1 to update)
+ *   [4-171]: LED data (56 * 3 bytes, GRB format)
+ */
+
+#include <stdint.h>
+#include <pru_cfg.h>
+
+/* Use P9_27 (R30 bit 5) - it's free! */
+#define LED_PIN     5
+#define NUM_LEDS    56
+
+/* WS2812 timing at 200MHz (5ns per cycle) */
+#define T0H     70      /* 350ns high for 0 bit */
+#define T0L     160     /* 800ns low for 0 bit */
+#define T1H     140     /* 700ns high for 1 bit */
+#define T1L     120     /* 600ns low for 1 bit */
+
+/* Shared memory base */
+#define SHARED_MEM  0x00010000
+
+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);
+    }
+}
+
+static void send_led(uint8_t g, uint8_t r, uint8_t b) {
+    send_byte(g);
+    send_byte(r);
+    send_byte(b);
+}
+
+void main(void) {
+    /* Enable OCP master port */
+    CT_CFG.SYSCFG_bit.STANDBY_INIT = 0;
+    
+    /* Clear output pin */
+    __R30 &= ~(1 << LED_PIN);
+    
+    while (1) {
+        /* Check trigger flag */
+        if (shared[1] == 1) {
+            uint8_t num = shared[0];
+            if (num > NUM_LEDS) num = NUM_LEDS;
+            
+            /* Send LED data (GRB format) */
+            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_led(g, r, b);
+            }
+            
+            /* Reset pulse (>50us) */
+            __R30 &= ~(1 << LED_PIN);
+            delay_cycles(10000);
+            
+            /* Clear trigger */
+            shared[1] = 0;
+        }
+    }
+}