Rob Dobson
Spidey Wall is the name for a physical wall lit up by multiple addressable LED strips. This program is an LPC1768 web server to control the wall from a browser.
Dependencies: EthernetInterfacePlusHostname RdWebServer mbed-rtos mbed
This project is part of a Light-Wall using addressable LED strips (WS2801). I have published a few posts on my blog about the construction of the wall and building a game to play on it (PacMan). I have also had a guest post from a friend who has set his children the task of producing some interesting animations. The original post is http://robdobson.com/2015/07/spidey-wall/ 
So far, however, I hadn't fully connected the physical (and electronic) wall with the web-browser creations to drive it. This project is hopefully the final link. A fast and reliable web server using REST commands to drive the 1686 LEDs in the Spidey Wall from code running in a browser (say on an iPad while you are playing a game).
The approach taken here results in the ability to control the RGB values of all 1686 LEDs at a rate of 20 frames per second.
A blog post describing the whole thing is here:
http://robdobson.com/2015/08/a-reliable-mbed-webserver/
Diff: ledstrip.cpp
- Revision:
- 1:362331cec9b7
- Parent:
- 0:887096209439
- Child:
- 2:99eb4c6e9ea4
--- a/ledstrip.cpp Tue Aug 18 16:03:29 2015 +0000
+++ b/ledstrip.cpp Thu Aug 20 07:41:02 2015 +0000
@@ -1,3 +1,7 @@
+// LED Strip using WS2801 with two ISRs for two SPI connected
+// LED strips running in parallel
+// Rob Dobson 2013-2014
+
#include "ledstrip.h"
#include "colourconverters.h"
#include "stddef.h"
@@ -6,50 +10,51 @@
#define SSP_IMSC_TX_RDY 3
#define SSP_IMSC_BITMASK 0x0f
-volatile int mCurPos0;
-int mEndPos0;
-volatile int mCurPos1;
-int mEndPos1;
-volatile bool mShowingLeds0;
-volatile bool mShowingLeds1;
-unsigned char* pLedValues;
-bool inISR;
+volatile int mCurPos0 = 0;
+int mEndPos0 = 0;
+volatile bool isr0Busy = false;
+unsigned char* pLedValues0 = NULL;
extern "C" void spi0_isr()
{
if (mCurPos0 < mEndPos0)
{
- LPC_SSP0->DR = pLedValues[mCurPos0]; // write to FIFO data register
+ LPC_SSP0->DR = pLedValues0[mCurPos0]; // write to FIFO data register
mCurPos0++;
}
else
{
// Turn off interrupts
LPC_SSP0->IMSC = 0;
- mShowingLeds0 = false;
+ isr0Busy = false;
}
}
+volatile int mCurPos1 = 0;
+int mEndPos1 = 0;
+volatile bool isr1Busy = false;
+unsigned char* pLedValues1 = NULL;
+
extern "C" void spi1_isr()
{
if (mCurPos1 < mEndPos1)
{
- LPC_SSP1->DR = pLedValues[mCurPos1]; // write to FIFO data register
+ LPC_SSP1->DR = pLedValues1[mCurPos1]; // write to FIFO data register
mCurPos1++;
}
else
{
// Turn off interrupts
LPC_SSP1->IMSC = 0;
- mShowingLeds1 = false;
+ isr1Busy = false;
}
}
ledstrip::ledstrip(int length, int splitPoint)
{
- mpLedValuesA = 0;
- mpLedValuesB = 0;
- mpCurLedValues = 0;
+ mpLedValuesA = NULL;
+ mpLedValuesB = NULL;
+ mpCurLedValues = NULL;
// SPI0 (using SSP 0 in 1768 chip)
mpSPI0 = new SPI(p11, NC, p13);
@@ -70,10 +75,7 @@
NVIC_ClearPendingIRQ(SSP1_IRQn);
NVIC_SetPriority(SSP1_IRQn, 2);
NVIC_EnableIRQ(SSP1_IRQn);
-
- // Enable interrupts
- __enable_irq();
-
+
// Resize the string length
Resize(length, splitPoint);
}
@@ -86,11 +88,11 @@
bool ledstrip::Resize(int length, int splitPoint)
{
- if (mShowingLeds0 || mShowingLeds1)
+ if (isr0Busy || isr1Busy)
return false;
- if (mpLedValuesA != 0)
+ if (mpLedValuesA != NULL)
delete mpLedValuesA;
- if (mpLedValuesB != 0)
+ if (mpLedValuesB != NULL)
delete mpLedValuesB;
mLedsBufSize = length*mColoursPerLed;
mpLedValuesA = new unsigned char[mLedsBufSize];
@@ -131,9 +133,20 @@
bool ledstrip::IsBusy()
{
- return mShowingLeds0 || mShowingLeds1;
+ return isr0Busy || isr1Busy;
}
+void ledstrip::RawFill(int startLed, int numLeds, const unsigned char* pLedVals)
+{
+ if ((startLed < 0) || (startLed >= mLedsInStrip))
+ return;
+ if (numLeds >= mLedsInStrip - startLed)
+ numLeds = mLedsInStrip - startLed;
+ int pos = startLed * mColoursPerLed;
+ unsigned char* pBuf = GetBuffer() + pos;
+ memcpy(pBuf, pLedVals, numLeds * mColoursPerLed);
+}
+
// Fill - solid colour
void ledstrip::Fill(int startLed, int numLeds,
int r1, int g1, int b1)
@@ -218,13 +231,12 @@
*/
}
-
void ledstrip::ShowLeds()
{
// Check if busy
- while (mShowingLeds0 || mShowingLeds1)
- ;
- wait_us(750);
+ while (isr0Busy || isr1Busy)
+ wait_us(2000);
+ wait_us(2000);
// Set up start points
mCurPos0 = 0;
@@ -233,53 +245,28 @@
mEndPos1 = mLedsInStrip*mColoursPerLed;
// Set the buffer for the ISRs
- pLedValues = mpCurLedValues;
-
+ pLedValues0 = mpCurLedValues;
+ pLedValues1 = mpCurLedValues;
+
// Flip the current buffer to the alternate one for interleaved writing
if (mpCurLedValues == mpLedValuesA)
+ {
+ memcpy(mpLedValuesB, mpLedValuesA, mLedsBufSize);
mpCurLedValues = mpLedValuesB;
+ }
else
+ {
+ memcpy(mpLedValuesA, mpLedValuesB, mLedsBufSize);
mpCurLedValues = mpLedValuesA;
+ }
// Enable interrupts
- mShowingLeds0 = true;
- LPC_SSP0->IMSC = (1 << SSP_IMSC_TX_RDY) & SSP_IMSC_BITMASK;
+ isr0Busy = true;
+ if (mSplitPoint < mLedsInStrip)
+ isr1Busy = true;
// Check if second strip is used
+ LPC_SSP0->IMSC = (1 << SSP_IMSC_TX_RDY) & SSP_IMSC_BITMASK;
if (mSplitPoint < mLedsInStrip)
- {
LPC_SSP1->IMSC = (1 << SSP_IMSC_TX_RDY) & SSP_IMSC_BITMASK;
- mShowingLeds1 = true;
- }
- // for (int q = 0; q < mLedsInStrip*3; q+=3)
- // printf("%d %02x%02x%02x\n", q/3, mpLedValues[q], mpLedValues[q+1], mpLedValues[q+2]);
-/*
- int pos1 = 0;
- int pos2 = mSplitPoint * mColoursPerLed;
- for (int j = 0; j < mMaxChainLength; j++)
- {
- for (int k = 0; k < mColoursPerLed; k++)
- {
- unsigned char tval1 = 0;
- if (pos1 + k < mLedsBufSize)
- tval1 = mpLedValues[pos1 + k];
- unsigned char tval2 = 0;
- if (pos2 + k < mLedsBufSize)
- tval2 = mpLedValues[pos2 + k];
- for (int i = 0; i < 8; i++)
- {
- dat1 = (tval1 & 0x80) != 0;
- tval1 = tval1 << 1;
- dat2 = (tval2 & 0x80) != 0;
- tval2 = tval2 << 1;
- clk = 1;
- clk = 0;
- wait_us(1);
- }
- }
- pos1 += mColoursPerLed;
- pos2 += mColoursPerLed;
- }
- wait_us(750);
-*/
}