Initial import

5 files changed, 237 insertions, 0 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
new file mode 100644
index 0000000..b7624e5
--- /dev/null
+++ b/CMakeLists.txt
@@ -0,0 +1,20 @@
+cmake_minimum_required(VERSION 3.12)
+
+include(pico_sdk_import.cmake)
+
+project(pixelhub C CXX)
+set(CMAKE_CXX_STANDARD 17)
+
+pico_sdk_init()
+
+include(Pico-DMX/interfaceLibForPicoSDK.cmake)
+
+add_executable(pixelhub pixelhub.cpp)
+target_link_libraries(pixelhub
+                      pico_stdlib
+		      picodmx
+		      hardware_pio)
+pico_add_extra_outputs(pixelhub)
+
+pico_generate_pio_header(pixelhub ${CMAKE_CURRENT_LIST_DIR}/ws2812.pio)
+target_include_directories(pixelhub PRIVATE ${CMAKE_CURRENT_LIST_DIR})
diff --git a/compile b/compile
new file mode 100755
index 0000000..2586e78
--- /dev/null
+++ b/compile
@@ -0,0 +1,9 @@
+#!/bin/sh
+
+export PICO_SDK_PATH=/mnt/datassd/2023/pico/pico-sdk/
+rm -rf build
+mkdir build
+cd build
+cmake .. -DPICO_BOARD=pico
+cd ..
+make -C build
diff --git a/pico_sdk_import.cmake b/pico_sdk_import.cmake
new file mode 100644
index 0000000..65f8a6f
--- /dev/null
+++ b/pico_sdk_import.cmake
@@ -0,0 +1,73 @@
+# This is a copy of <PICO_SDK_PATH>/external/pico_sdk_import.cmake
+
+# This can be dropped into an external project to help locate this SDK
+# It should be include()ed prior to project()
+
+if (DEFINED ENV{PICO_SDK_PATH} AND (NOT PICO_SDK_PATH))
+    set(PICO_SDK_PATH $ENV{PICO_SDK_PATH})
+    message("Using PICO_SDK_PATH from environment ('${PICO_SDK_PATH}')")
+endif ()
+
+if (DEFINED ENV{PICO_SDK_FETCH_FROM_GIT} AND (NOT PICO_SDK_FETCH_FROM_GIT))
+    set(PICO_SDK_FETCH_FROM_GIT $ENV{PICO_SDK_FETCH_FROM_GIT})
+    message("Using PICO_SDK_FETCH_FROM_GIT from environment ('${PICO_SDK_FETCH_FROM_GIT}')")
+endif ()
+
+if (DEFINED ENV{PICO_SDK_FETCH_FROM_GIT_PATH} AND (NOT PICO_SDK_FETCH_FROM_GIT_PATH))
+    set(PICO_SDK_FETCH_FROM_GIT_PATH $ENV{PICO_SDK_FETCH_FROM_GIT_PATH})
+    message("Using PICO_SDK_FETCH_FROM_GIT_PATH from environment ('${PICO_SDK_FETCH_FROM_GIT_PATH}')")
+endif ()
+
+set(PICO_SDK_PATH "${PICO_SDK_PATH}" CACHE PATH "Path to the Raspberry Pi Pico SDK")
+set(PICO_SDK_FETCH_FROM_GIT "${PICO_SDK_FETCH_FROM_GIT}" CACHE BOOL "Set to ON to fetch copy of SDK from git if not otherwise locatable")
+set(PICO_SDK_FETCH_FROM_GIT_PATH "${PICO_SDK_FETCH_FROM_GIT_PATH}" CACHE FILEPATH "location to download SDK")
+
+if (NOT PICO_SDK_PATH)
+    if (PICO_SDK_FETCH_FROM_GIT)
+        include(FetchContent)
+        set(FETCHCONTENT_BASE_DIR_SAVE ${FETCHCONTENT_BASE_DIR})
+        if (PICO_SDK_FETCH_FROM_GIT_PATH)
+            get_filename_component(FETCHCONTENT_BASE_DIR "${PICO_SDK_FETCH_FROM_GIT_PATH}" REALPATH BASE_DIR "${CMAKE_SOURCE_DIR}")
+        endif ()
+        # GIT_SUBMODULES_RECURSE was added in 3.17
+        if (${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.17.0")
+            FetchContent_Declare(
+                    pico_sdk
+                    GIT_REPOSITORY https://github.com/raspberrypi/pico-sdk
+                    GIT_TAG master
+                    GIT_SUBMODULES_RECURSE FALSE
+            )
+        else ()
+            FetchContent_Declare(
+                    pico_sdk
+                    GIT_REPOSITORY https://github.com/raspberrypi/pico-sdk
+                    GIT_TAG master
+            )
+        endif ()
+
+        if (NOT pico_sdk)
+            message("Downloading Raspberry Pi Pico SDK")
+            FetchContent_Populate(pico_sdk)
+            set(PICO_SDK_PATH ${pico_sdk_SOURCE_DIR})
+        endif ()
+        set(FETCHCONTENT_BASE_DIR ${FETCHCONTENT_BASE_DIR_SAVE})
+    else ()
+        message(FATAL_ERROR
+                "SDK location was not specified. Please set PICO_SDK_PATH or set PICO_SDK_FETCH_FROM_GIT to on to fetch from git."
+                )
+    endif ()
+endif ()
+
+get_filename_component(PICO_SDK_PATH "${PICO_SDK_PATH}" REALPATH BASE_DIR "${CMAKE_BINARY_DIR}")
+if (NOT EXISTS ${PICO_SDK_PATH})
+    message(FATAL_ERROR "Directory '${PICO_SDK_PATH}' not found")
+endif ()
+
+set(PICO_SDK_INIT_CMAKE_FILE ${PICO_SDK_PATH}/pico_sdk_init.cmake)
+if (NOT EXISTS ${PICO_SDK_INIT_CMAKE_FILE})
+    message(FATAL_ERROR "Directory '${PICO_SDK_PATH}' does not appear to contain the Raspberry Pi Pico SDK")
+endif ()
+
+set(PICO_SDK_PATH ${PICO_SDK_PATH} CACHE PATH "Path to the Raspberry Pi Pico SDK" FORCE)
+
+include(${PICO_SDK_INIT_CMAKE_FILE})
diff --git a/pixelhub.cpp b/pixelhub.cpp
new file mode 100644
index 0000000..f876e08
--- /dev/null
+++ b/pixelhub.cpp
@@ -0,0 +1,87 @@
+/*
+ * pixelhub.c
+ *
+ * DMX to neopixel interface
+ *
+ * Copyright © 2023 Thomas White <taw@physics.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with This program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <pico/stdlib.h>
+#include <DmxInput.h>
+#include <ws2812.pio.h>
+
+const int dmx_rx_pin = 16;
+const int pixels_pin = 2;
+const int num_pixels = 8;
+const PIO led_pio = pio0;
+uint led_pio_sm;
+
+
+static inline void put_pixel(uint32_t pixel_grb) {
+	pio_sm_put_blocking(led_pio, led_pio_sm, pixel_grb << 8u);
+}
+
+
+static inline uint32_t urgb_u32(uint8_t r, uint8_t g, uint8_t b) {
+	return ((uint32_t) (r) << 8) | ((uint32_t) (g) << 16) | (uint32_t) (b);
+}
+
+
+int main()
+{
+	DmxInput dmx_in;
+	uint offset;
+	uint8_t dmxbuf[512];
+	uint32_t pixelbuf[num_pixels];
+	int i;
+	int blink = 1;
+
+	/* Initialise DMX */
+	dmx_in.begin(dmx_rx_pin, 1, 512);
+
+	/* Initialise Neopixels */
+	led_pio_sm = pio_claim_unused_sm(led_pio, true);
+    	offset = pio_add_program(led_pio, &ws2812_program);
+	ws2812_program_init(led_pio, led_pio_sm, offset, pixels_pin, 800000, false);
+
+	/* Status LED */
+	gpio_init(PICO_DEFAULT_LED_PIN);
+	gpio_set_dir(PICO_DEFAULT_LED_PIN, GPIO_OUT);
+
+	for ( i=0; i<num_pixels; i++ ) {
+		pixelbuf[i] = 0x00000000;  /* (W)GRB */
+	}
+
+	while (1) {
+
+		dmx_in.read(dmxbuf);
+
+		for ( i=0; i<num_pixels; i++) {
+			pixelbuf[i] = urgb_u32(dmxbuf[1+3*i+0],
+			                       dmxbuf[1+3*i+1],
+			                       dmxbuf[1+3*i+2]);
+		}
+
+		for ( i=0; i<num_pixels; i++) {
+			put_pixel(pixelbuf[i]);
+		}
+
+		gpio_put(PICO_DEFAULT_LED_PIN, blink);
+		blink = 1 - blink;
+		//sleep_us(100000);
+	}
+}
diff --git a/ws2812.pio b/ws2812.pio
new file mode 100644
index 0000000..ae19a6b
--- /dev/null
+++ b/ws2812.pio
@@ -0,0 +1,48 @@
+;
+; Copyright (c) 2020 Raspberry Pi (Trading) Ltd.
+;
+; SPDX-License-Identifier: BSD-3-Clause
+;
+
+.program ws2812
+.side_set 1
+
+.define public T1 2
+.define public T2 5
+.define public T3 3
+
+.lang_opt python sideset_init = pico.PIO.OUT_HIGH
+.lang_opt python out_init     = pico.PIO.OUT_HIGH
+.lang_opt python out_shiftdir = 1
+
+.wrap_target
+bitloop:
+    out x, 1       side 0 [T3 - 1] ; Side-set still takes place when instruction stalls
+    jmp !x do_zero side 1 [T1 - 1] ; Branch on the bit we shifted out. Positive pulse
+do_one:
+    jmp  bitloop   side 1 [T2 - 1] ; Continue driving high, for a long pulse
+do_zero:
+    nop            side 0 [T2 - 1] ; Or drive low, for a short pulse
+.wrap
+
+% c-sdk {
+#include "hardware/clocks.h"
+
+static inline void ws2812_program_init(PIO pio, uint sm, uint offset, uint pin, float freq, bool rgbw) {
+
+    pio_gpio_init(pio, pin);
+    pio_sm_set_consecutive_pindirs(pio, sm, pin, 1, true);
+
+    pio_sm_config c = ws2812_program_get_default_config(offset);
+    sm_config_set_sideset_pins(&c, pin);
+    sm_config_set_out_shift(&c, false, true, rgbw ? 32 : 24);
+    sm_config_set_fifo_join(&c, PIO_FIFO_JOIN_TX);
+
+    int cycles_per_bit = ws2812_T1 + ws2812_T2 + ws2812_T3;
+    float div = clock_get_hz(clk_sys) / (freq * cycles_per_bit);
+    sm_config_set_clkdiv(&c, div);
+
+    pio_sm_init(pio, sm, offset, &c);
+    pio_sm_set_enabled(pio, sm, true);
+}
+%}