Diff: FastPixelLPD8806.cpp

Revision:

10:5b3be78ce6bd

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/FastPixelLPD8806.cpp	Sat May 31 18:41:56 2014 +0000
@@ -0,0 +1,210 @@
+/***************************************************************************/
+// DMA-enabled high data rate driver for Heroic Robotics FastPixel strips.
+// Written by Jas Strong <jasmine@heroicrobotics.com>
+// Copyright (c) 2013-2014 Heroic Robotics, Inc.
+//
+// FastPixel is a family of high performance LED strips available from
+// Heroic Robotics, Inc.  http://heroicrobotics.com/ - check them out!
+//
+// These strips are capable of supporting 18 Mbit/sec when run on PixelPusher
+// hardware;  your performance on mbed is likely to be somewhat lower due to
+// the lack of high performance driver chips on the SPI lines.
+//
+// Heroic Robotics also sells a family of dedicated LED controllers called
+// PixelPusher-  almost certainly the best LED controller in the world.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+//
+//
+// Some code originally from:
+// Mbed library to control LPD8806-based RGB LED Strips
+// (c) 2011 Jelmer Tiete
+// That library is ported from the Arduino implementation of Adafruit Industries
+// found at: http://github.com/adafruit/LPD8806
+// and their strips: http://www.adafruit.com/products/306
+// Released under the MIT License: http://mbed.org/license/mit
+//
+// Parameterized and modified to use soft SPI.
+// Jas Strong <jasmine@electronpusher.org>
+// Then remonstered to use hardware SPI for blast mode.
+//
+/*****************************************************************************/
+
+#include "LedStrip.h"
+#include "FastPixelLPD8806.h"
+
+#include "MODDMA.h"
+
+#define LATCHNUMBER 32
+#define FAST_PIXEL_MHZ 18
+
+// DMA controller and frequency setting
+extern MODDMA dma;
+extern int current_strip_fill;
+ 
+ // when the transfer is complete, kill the channel.
+void dma_complete_callback() {
+    MODDMA_Config *config = dma.getConfig();
+    dma.Disable( (MODDMA::CHANNELS)config->channelNum() );
+    
+    // clear the IRQ flags
+    if (dma.irqType() == MODDMA::TcIrq) dma.clearTcIrq();    
+    if (dma.irqType() == MODDMA::ErrIrq) dma.clearErrIrq();  
+}
+ 
+void dma_err_callback() {
+    MODDMA_Config *config = dma.getConfig();
+    dma.Disable( (MODDMA::CHANNELS)config->channelNum() );
+    
+    // clear the IRQ flags
+    if (dma.irqType() == MODDMA::TcIrq) dma.clearTcIrq();    
+    if (dma.irqType() == MODDMA::ErrIrq) dma.clearErrIrq();  
+} 
+
+FastPixelLPD8806::FastPixelLPD8806(PinName dataPin, PinName clockPin, int n) :
+    _spi(dataPin, NC, clockPin)
+ {
+    // Allocate 3 bytes per pixel plus latch bytes
+    numLEDs = n;
+    pixels = (uint8_t *)malloc(numLEDs * 3 + ((numLEDs + LATCHNUMBER-1) / LATCHNUMBER));
+    if (pixels) {
+        memset(pixels, 0x80, numLEDs * 3); // Init to RGB 'off' state
+        memset(pixels+numLEDs*3, 0x0, (numLEDs + LATCHNUMBER-1) / LATCHNUMBER); // latch data
+    }
+        
+    _spi.format(8,0);
+    _spi.frequency(FAST_PIXEL_MHZ*1000000);
+    
+    // remember which strip we are
+    strip_num = current_strip_fill;
+    
+    // make a new DMA config
+    dma_config = new MODDMA_Config;
+}
+ 
+inline void FastPixelLPD8806::write(uint8_t byte) {
+    _spi.write(byte);
+}
+
+
+void FastPixelLPD8806::begin(void) {
+
+    blank();
+    show();
+    show();
+}
+
+uint16_t FastPixelLPD8806::numPixels(void) {
+    return numLEDs;
+}
+
+void FastPixelLPD8806::blank(void) {
+    memset(pixels, 0x80, numLEDs * 3);
+}
+
+// Set up the DMA controller;  we only have two SSP peripherals, so only two strips.
+
+void FastPixelLPD8806::show(void) {
+     if (strip_num == 0) {
+        dma_config  -> channelNum   (MODDMA::Channel_0)
+                    -> srcMemAddr   ( (uint32_t) pixels )
+                    -> dstMemAddr   ( MODDMA::SSP0_Tx )
+                    -> transferSize (numLEDs * 3 + ((numLEDs + LATCHNUMBER-1) / LATCHNUMBER))
+                    -> transferType (MODDMA::m2p)
+                    -> dstConn      (MODDMA::SSP0_Tx)
+                    -> attach_tc    (&dma_complete_callback)
+                    -> attach_err   (&dma_err_callback);
+       LPC_SSP0->DMACR = (1<<1)|(1<<0); // TX,RXDMAE
+    } else {
+        dma_config  -> channelNum   (MODDMA::Channel_1)
+                    -> srcMemAddr   ( (uint32_t) pixels )
+                    -> dstMemAddr   ( MODDMA::SSP1_Tx )
+                    -> transferSize (numLEDs * 3 + ((numLEDs +LATCHNUMBER-1) / LATCHNUMBER))
+                    -> transferType (MODDMA::m2p)
+                    -> dstConn      (MODDMA::SSP1_Tx)
+                    -> attach_tc    (&dma_complete_callback)
+                    -> attach_err   (&dma_err_callback);
+       LPC_SSP1->DMACR = (1<<1)|(1<<0); // TX,RXDMAE
+    }
+    while (dma.Enabled(dma_config->channelNum())) {
+        __nop();
+    }
+    dma.Setup(dma_config);
+    dma.Enable(dma_config);
+}
+
+// LPD8806 is 7-bit, so we shift to normalize to 256 PWM steps.
+uint32_t FastPixelLPD8806::total_luminance(void) {
+    uint32_t running_total;
+    running_total = 0;
+    for (int i=0; i<numLEDs*3; i++)
+        running_total += ((pixels[i] & 0x7f) <<1);
+    return running_total;
+}
+
+// Convert R,G,B to combined 32-bit color
+uint32_t FastPixelLPD8806::Color(uint8_t r, uint8_t g, uint8_t b) {
+    // Take the lowest 7 bits of each value and append them end to end
+    // We have the top bit set high (its a 'parity-like' bit in the protocol
+    // and must be set!)
+    return 0x808080 | ((uint32_t)(g>>1) << 16) | ((uint32_t)(r>>1) << 8) | (uint32_t)(b>>1);
+}
+
+// store the rgb component in our array
+void FastPixelLPD8806::setPixelColor(uint16_t n, uint8_t r, uint8_t g, uint8_t b) {
+    if (n >= numLEDs) return; // '>=' because arrays are 0-indexed
+
+    pixels[n*3  ] = (g>>1) | 0x80;
+    pixels[n*3+1] = (r>>1) | 0x80;
+    pixels[n*3+2] = (b>>1) | 0x80;
+}
+
+void FastPixelLPD8806::setPixelR(uint16_t n, uint8_t r) {
+    if (n >= numLEDs) return; // '>=' because arrays are 0-indexed
+
+    pixels[n*3+1] = (r>>1) | 0x80;
+}
+
+void FastPixelLPD8806::setPixelG(uint16_t n, uint8_t g) {
+    if (n >= numLEDs) return; // '>=' because arrays are 0-indexed
+
+    pixels[n*3] = (g>>1) | 0x80;
+}
+
+void FastPixelLPD8806::setPixelB(uint16_t n, uint8_t b) {
+    if (n >= numLEDs) return; // '>=' because arrays are 0-indexed
+
+    pixels[n*3+2] = (b>>1) | 0x80;
+}
+
+// Set all in one function call, assuming GRB ordering
+void FastPixelLPD8806::setPackedPixels(uint8_t * buffer, uint32_t n) {
+    if (n >= numLEDs) return;
+    for (int i=0; i<n*3; i++)
+        buffer[i] = (buffer[i] >> 1) | 0x80;
+    memcpy(pixels, buffer, (size_t) (n*3));
+}
+
+void FastPixelLPD8806::setPixelColor(uint16_t n, uint32_t c) {
+    if (n >= numLEDs) return; // '>=' because arrays are 0-indexed
+
+    pixels[n*3  ] = (c >> 16) | 0x80;
+    pixels[n*3+1] = (c >>  8) | 0x80;
+    pixels[n*3+2] =  c        | 0x80;
+}