97 lines
2.3 KiB
C++
97 lines
2.3 KiB
C++
// NeoPixel ring driver.
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//
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// Copyright 2015 Google Inc.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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//
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#include "neopixel.h"
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#include "chip.h"
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#include <cstring>
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#define CFG_ENABLE (1<<0)
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#define CFG_MASTER (1<<2)
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const uint16_t NeoPixel::bits_[] = {
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0b100100100100,
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0b100100100110,
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0b100100110100,
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0b100100110110,
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0b100110100100,
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0b100110100110,
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0b100110110100,
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0b100110110110,
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0b110100100100,
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0b110100100110,
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0b110100110100,
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0b110100110110,
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0b110110100100,
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0b110110100110,
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0b110110110100,
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0b110110110110,
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};
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/// Initialise the hardware.
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void NeoPixel::init() {
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clear();
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LPC_FMC->FLASHCFG = 0; // 1 wait state instead of 1
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LPC_SWM->PINENABLE0 |= 1<<2; // disable SWCLK
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LPC_SWM->PINASSIGN[4] = 0xFFFFFF03UL; // SPI0_MOSI 3
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/* Enable SPI0 clock */
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LPC_SYSCON->SYSAHBCLKCTRL |= (1<<11);
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LPC_SYSCON->PRESETCTRL &= ~(1<<0);
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LPC_SYSCON->PRESETCTRL |= (1<<0);
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// 2.4 MHz, i.e. 12 MHz / 5
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LPC_SPI0->DIV = 4;
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LPC_SPI0->DLY = 0;
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LPC_SPI0->TXCTRL = SPI_TXDATCTL_FLEN(12-1) | SPI_TXDATCTL_RXIGNORE;
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LPC_SPI0->CFG = CFG_MASTER;
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LPC_SPI0->CFG |= CFG_ENABLE;
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}
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/// Set all the LEDs to off and restart at the first LED.
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void NeoPixel::clear() {
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p_ = bytes_;
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memset(bytes_, 0, sizeof(bytes_));
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}
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/// Append a byte to the stream.
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void NeoPixel::append(uint8_t b) {
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if (p_ <= (bytes_ + sizeof(bytes_))) {
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*p_++ = b;
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}
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}
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void NeoPixel::send(uint16_t cmd) {
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while ((LPC_SPI0->STAT & SPI_STAT_TXRDY) == 0) {}
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LPC_SPI0->TXDAT = cmd;
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}
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/// Write to the LEDs.
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void NeoPixel::write() {
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send(0);
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send(0);
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for (auto p = bytes_; p < bytes_ + sizeof(bytes_); p++) {
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auto ch = *p;
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send(bits_[ch >> 4]);
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send(bits_[ch & 0xF]);
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}
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}
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