From fd0a69fb778d4ca6896befd90ae3123e0eda311b Mon Sep 17 00:00:00 2001
From: tostadora <tostadora@gmail.com>
Date: Thu, 16 Jan 2014 20:34:56 +0100
Subject: [PATCH] untested support for the P9813 chip

Former-commit-id: df7341af27503fffd5be9b0afd9525e52dccbebb
---
 libsrc/leddevice/LedDeviceP9813.cpp | 28 +++++++++++++++++++++++++---
 libsrc/leddevice/LedDeviceP9813.h   |  1 +
 2 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/libsrc/leddevice/LedDeviceP9813.cpp b/libsrc/leddevice/LedDeviceP9813.cpp
index 457cfe8c..6b0654ef 100644
--- a/libsrc/leddevice/LedDeviceP9813.cpp
+++ b/libsrc/leddevice/LedDeviceP9813.cpp
@@ -22,13 +22,35 @@ int LedDeviceP9813::write(const std::vector<ColorRgb> &ledValues)
 {
 	mLedCount = ledValues.size();
 
-	const unsigned dataLen = ledValues.size() * sizeof(ColorRgb);
-	const uint8_t * dataPtr = reinterpret_cast<const uint8_t *>(ledValues.data());
+	const unsigned dataLen = ledValues.size() * 4 + 8;
+	uint8_t data[dataLen];
 
-	return writeBytes(dataLen, dataPtr);
+    memset(data, 0x00, dataLen);
+
+    int j = 4;
+    for (unsigned i = 0; i < mLedCount; i++){
+        data[j++] = calculateChecksum(ledValues[i]);
+        data[j++] = ledValues[i].blue;        
+        data[j++] = ledValues[i].green;        
+        data[j++] = ledValues[i].red;        
+    }
+
+	return writeBytes(dataLen, data);
 }
 
 int LedDeviceP9813::switchOff()
 {
 	return write(std::vector<ColorRgb>(mLedCount, ColorRgb{0,0,0}));
 }
+
+const uint8_t LedDeviceP9813::calculateChecksum(const ColorRgb color)
+{
+    uint8_t res = 0;
+
+    res |= (uint8_t)0x03 << 6;  
+    res |= (uint8_t)(~(color.blue  >> 6) & 0x03) << 4; 
+    res |= (uint8_t)(~(color.green >> 6) & 0x03) << 2;    
+    res |= (uint8_t)(~(color.red   >> 6) & 0x03); 
+
+    return res;
+}
diff --git a/libsrc/leddevice/LedDeviceP9813.h b/libsrc/leddevice/LedDeviceP9813.h
index 3559354b..a76df140 100644
--- a/libsrc/leddevice/LedDeviceP9813.h
+++ b/libsrc/leddevice/LedDeviceP9813.h
@@ -36,4 +36,5 @@ private:
 
 	/// the number of leds
 	size_t mLedCount;
+	const uint8_t calculateChecksum(const ColorRgb color);
 };