diff --git a/libraries/TLC5917/.arduino-ci.yml b/libraries/TLC5917/.arduino-ci.yml
new file mode 100644
index 00000000..10c0e10b
--- /dev/null
+++ b/libraries/TLC5917/.arduino-ci.yml
@@ -0,0 +1,28 @@
+platforms:
+  rpipico:
+    board: rp2040:rp2040:rpipico
+    package: rp2040:rp2040
+    gcc:
+      features:
+      defines:
+        - ARDUINO_ARCH_RP2040
+      warnings:
+      flags:
+
+packages:
+  rp2040:rp2040:
+    url: https://github.com/earlephilhower/arduino-pico/releases/download/global/package_rp2040_index.json
+
+compile:
+  # Choosing to run compilation tests on 2 different Arduino platforms
+  platforms:
+    - uno
+    # - due
+    # - zero
+    # - leonardo
+    - m4
+    - esp32
+    # - esp8266
+    # - mega2560
+    - rpipico
+
diff --git a/libraries/TLC5917/.github/FUNDING.yml b/libraries/TLC5917/.github/FUNDING.yml
new file mode 100644
index 00000000..554358c3
--- /dev/null
+++ b/libraries/TLC5917/.github/FUNDING.yml
@@ -0,0 +1,4 @@
+# These are supported funding model platforms
+
+github: RobTillaart
+custom: "https://www.paypal.me/robtillaart"
diff --git a/libraries/TLC5917/.github/workflows/arduino-lint.yml b/libraries/TLC5917/.github/workflows/arduino-lint.yml
new file mode 100644
index 00000000..982a5df2
--- /dev/null
+++ b/libraries/TLC5917/.github/workflows/arduino-lint.yml
@@ -0,0 +1,16 @@
+
+name: Arduino-lint
+
+on: [push, pull_request]
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    steps:
+      - uses: actions/checkout@v4
+      - uses: arduino/arduino-lint-action@v1
+        with:
+          library-manager: update
+          compliance: strict
+          verbose: false
+
diff --git a/libraries/TLC5917/.github/workflows/arduino_test_runner.yml b/libraries/TLC5917/.github/workflows/arduino_test_runner.yml
new file mode 100644
index 00000000..393c2257
--- /dev/null
+++ b/libraries/TLC5917/.github/workflows/arduino_test_runner.yml
@@ -0,0 +1,19 @@
+---
+name: Arduino CI
+
+on: [push, pull_request]
+
+jobs:
+  runTest:
+    runs-on: ubuntu-latest
+    timeout-minutes: 20
+
+    steps:
+      - uses: actions/checkout@v4
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: 2.6
+      - run: |
+          sudo sysctl vm.mmap_rnd_bits=28
+          gem install arduino_ci
+          arduino_ci.rb
diff --git a/libraries/TLC5917/.github/workflows/jsoncheck.yml b/libraries/TLC5917/.github/workflows/jsoncheck.yml
new file mode 100644
index 00000000..fd05f5f8
--- /dev/null
+++ b/libraries/TLC5917/.github/workflows/jsoncheck.yml
@@ -0,0 +1,19 @@
+name: JSON check
+
+on:
+  push:
+    paths:
+      - '**.json'
+  pull_request:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    steps:
+      - uses: actions/checkout@v4
+      - name: json-syntax-check
+        uses: limitusus/json-syntax-check@v2
+        with:
+          pattern: "\\.json$"
+
diff --git a/libraries/TLC5917/CHANGELOG.md b/libraries/TLC5917/CHANGELOG.md
new file mode 100644
index 00000000..32f9d7c0
--- /dev/null
+++ b/libraries/TLC5917/CHANGELOG.md
@@ -0,0 +1,12 @@
+# Change Log TLC5917
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](http://keepachangelog.com/)
+and this project adheres to [Semantic Versioning](http://semver.org/).
+
+
+## [0.1.0] - 2024-03-17
+- initial version
+
+
diff --git a/libraries/TLC5917/LICENSE b/libraries/TLC5917/LICENSE
new file mode 100644
index 00000000..37fe70e5
--- /dev/null
+++ b/libraries/TLC5917/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2024-2024 Rob Tillaart
+
+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.
diff --git a/libraries/TLC5917/README.md b/libraries/TLC5917/README.md
new file mode 100644
index 00000000..962497c8
--- /dev/null
+++ b/libraries/TLC5917/README.md
@@ -0,0 +1,182 @@
+
+[![Arduino CI](https://github.com/RobTillaart/TLC5917/workflows/Arduino%20CI/badge.svg)](https://github.com/marketplace/actions/arduino_ci)
+[![Arduino-lint](https://github.com/RobTillaart/TLC5917/actions/workflows/arduino-lint.yml/badge.svg)](https://github.com/RobTillaart/TLC5917/actions/workflows/arduino-lint.yml)
+[![JSON check](https://github.com/RobTillaart/TLC5917/actions/workflows/jsoncheck.yml/badge.svg)](https://github.com/RobTillaart/TLC5917/actions/workflows/jsoncheck.yml)
+[![GitHub issues](https://img.shields.io/github/issues/RobTillaart/TLC5917.svg)](https://github.com/RobTillaart/TLC5917/issues)
+
+[![License: MIT](https://img.shields.io/badge/license-MIT-green.svg)](https://github.com/RobTillaart/TLC5917/blob/master/LICENSE)
+[![GitHub release](https://img.shields.io/github/release/RobTillaart/TLC5917.svg?maxAge=3600)](https://github.com/RobTillaart/TLC5917/releases)
+[![PlatformIO Registry](https://badges.registry.platformio.org/packages/robtillaart/library/TLC5917.svg)](https://registry.platformio.org/libraries/robtillaart/TLC5917)
+
+
+# TLC5917
+
+TLC5917 is an Arduino library for TLC5917 8-Channel Constant-Current LED Sink Drivers.
+
+
+## Description
+
+**Experimental**
+
+This library allows control over the 8 channels of a TLC5917 device.
+
+
+TODO: Elaborate.
+
+The TLC5916 is a derived class that is functional identical to the TLC5917 (for now).
+When implementation proceeds this might change.
+
+The library is **experimental** and needs testing with Hardware.  
+Please share your experiences.
+
+
+(Changes of the interface are definitely possible).
+
+
+#### Daisy chaining
+
+This library supports daisy chaining.
+A constructor takes the number of devices as parameter and 
+an internal buffer is allocated (8 elements per device).
+This internal buffer is clocked into the devices with **write()**.
+
+
+#### Related
+
+- https://www.adafruit.com/product/1429
+- https://github.com/RobTillaart/TLC5917
+- https://github.com/RobTillaart/TLC5947
+- https://github.com/RobTillaart/PCA9634  (I2C)
+- https://github.com/RobTillaart/PCA9635  (I2C)
+- https://github.com/RobTillaart/PCA9685  (I2C)
+
+
+## Interface
+
+```cpp
+#include TLC5917.h
+```
+
+#### Constructor
+
+- **TLC5917(uint8_t clock, uint8_t data, uint8_t latch, uint8_t blank)** constructor.
+Single device constructor.
+Defines the pins used for uploading / writing the PWM data to the module.
+The blank pin is explained in more detail below. 
+- **TLC5917(int deviceCount, uint8_t clock, uint8_t data, uint8_t latch, uint8_t blank)** constructor.
+To be used for multiple devices, typical 2 or more.
+Defines the pins used for uploading / writing the PWM data to the module.
+The blank pin is explained in more detail below. 
+- **~TLC5917()** destructor
+
+#### Base
+
+- **bool begin()** set the pinModes of the pins and their initial values.
+The TLC is disabled by default, as the device has random values in its grey-scale register. 
+One must call **enable()** explicitly.
+- **int getChannels()** return the amount of channels == 8 x number of devices.
+- **bool setChannel(uint8_t channel, bool on)** set a channel on or off in the buffer.
+- **bool setChannel(uint8_t \* array)** copy a preset of channel settings in one call.
+- **bool setAll(bool on)** set all channels on or off.
+- **bool getChannel(uint8_t channel)** get current state of a channel in the cached buffer.
+- **void write()** writes the whole buffer (deviceCount x 8 values) to the device(s).
+- **void write(int n)** writes a part of the buffer (only **n** values) to the device.
+Typical used to speed up if less than max number e.g. only 17 channels are used
+and needs to be updated.  
+**experimental, might have side effects**
+
+
+**write()** must be called after setting all values one wants to change.
+Doing that per channel is far less efficient if one wants to update multiple 
+channels as fast as possible.
+See also **TLC5917_performance.ino** for an indication of time.
+
+
+#### Blank line  TODO CHECK
+ 
+The blank pin (OE line) is used to set all channels on or off.
+This allows to "preload" the registers with values and enable them all at once
+with very precise timing.
+
+Default a TLC device is disabled (by begin), so one should enable it "manually".  
+(P13 datasheet)
+
+- **void enable()** all channels reflect last PWM values written.
+- **void disable()** all channels are off / 0.
+- **bool isEnabled()** returns status of blank line.
+
+The library only supports one **enable() / blank line**. If you want
+a separate **enable()** per device you might need to connect the devices
+"in parallel" instead of "in series" (daisy chained).
+The blank parameter in the constructor should be set to -1 (out of range value).
+
+
+#### Configure gain
+
+See datasheet page 23 for details.
+
+- **void setCurrentAdjustMode()**
+- **void setNormalMode()**
+- **void writeConfiguration(uint8_t config)** See page 23 datasheet
+
+|      bit  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |
+|:---------:|:---:|:---:|:---:|:---:|:---:|:---:|:---:|:---:|
+|  meaning  |  CM |  HC | CC0 | CC1 | CC2 | CC3 | CC4 | CC5 |
+|  default  |  1  |  1  |  1  |  1  |  1  |  1  |  1  |  1  |
+
+CM limits the output current range.  
+- High Current Multiplier (CM = 1): 10 mA to 120 mA.
+- Low Current Multiplier  (CM = 0):  3 mA to  40 mA.
+
+VG (voltage gain) = (1 + HC) × (1 + D/64) / 4
+where  D = CC0 × 32 + CC1 × 16 + CC2 × 8 + CC3 × 4 + CC4 × 2 + CC5
+
+CG (current gain) = VG x pow(3, CM - 1)    
+
+```
+Default 
+CG = VG x 3;  
+VG = 2 x ( 1 + 63/64) / 4 = 127/128
+```
+
+TODO test with hardware to understand this in detail.  
+Actual current depends on Rext (see datasheet).
+
+
+## Performance
+
+See **TLC5917_performance.ino** for an indicative test.
+
+
+## Future
+
+#### Must
+
+- update documentation
+- buy hardware
+  - test test test 
+- get basic functionality running
+
+#### Should
+
+- get basic functionality running
+- investigate daisy chaining. (hardware needed).
+  - max CLOCK speed when chained (50% DutyCycle)
+  - what is clock in practice (e.g. an ESP32 240 MHz)
+
+#### Could
+
+- add examples
+
+#### Wont
+
+
+## Support
+
+If you appreciate my libraries, you can support the development and maintenance.
+Improve the quality of the libraries by providing issues and Pull Requests, or
+donate through PayPal or GitHub sponsors.
+
+Thank you,
+
+
diff --git a/libraries/TLC5917/TLC5917.cpp b/libraries/TLC5917/TLC5917.cpp
new file mode 100644
index 00000000..ae6a79e6
--- /dev/null
+++ b/libraries/TLC5917/TLC5917.cpp
@@ -0,0 +1,294 @@
+//
+//    FILE: TLC5917.cpp
+//  AUTHOR: Rob Tillaart
+// VERSION: 0.1.0
+//    DATE: 2024-03-17
+// PURPOSE: Arduino library for TLC5917 8-Channel Constant-Current LED Sink Drivers.
+//     URL: https://github.com/RobTillaart/TLC5917
+
+
+#include "TLC5917.h"
+
+
+TLC5917::TLC5917(uint8_t clock, uint8_t data, uint8_t LE, uint8_t OE)
+{
+  TLC5917(1, clock, data, LE, OE);
+}
+
+
+TLC5917::TLC5917(int deviceCount, uint8_t clock, uint8_t data, uint8_t LE, uint8_t OE)
+{
+  if (deviceCount <= 0) deviceCount = 1;
+  _channels = deviceCount * 8;
+  _clock    = clock;
+  _data     = data;
+  _le       = LE;
+  _oe       = OE;
+  _buffer   = (uint8_t *) calloc(_channels, sizeof(uint8_t));
+}
+
+
+TLC5917::~TLC5917()
+{
+  if (_buffer) free(_buffer);
+}
+
+
+bool TLC5917::begin()
+{
+  pinMode(_clock, OUTPUT);
+  pinMode(_data,  OUTPUT);
+  pinMode(_le, OUTPUT);
+  pinMode(_oe, OUTPUT);
+  digitalWrite(_clock, LOW);
+  digitalWrite(_data, LOW);
+  digitalWrite(_le, LOW);
+  //  disable by default, safest option.
+  disable();
+  return true;
+}
+
+
+int TLC5917::getChannels()
+{
+  return _channels;
+}
+
+
+bool TLC5917::setChannel(uint8_t channel, bool on)
+{
+  if (channel >= _channels) return false;
+  if (on) _buffer[channel / 8] |=  (1 << channel & 0x07);
+  else    _buffer[channel / 8] &= ~(1 << channel & 0x07);
+  return true;
+}
+
+
+bool TLC5917::setChannel(uint8_t * array)
+{
+  for (int i = 0; i < _channels / 8; i++)
+  {
+    _buffer[i] = array[i];
+  }
+  return true;
+}
+
+
+bool TLC5917::setAll(bool on)
+{
+  uint8_t mask = on ? 0xFF : 0x00;
+  for (int i = 0; i < _channels / 8; i++)
+  {
+    _buffer[i] = mask;
+  }
+  return true;
+}
+
+
+bool TLC5917::getChannel(uint8_t channel)
+{
+  if (channel >= _channels) return false;
+  return (_buffer[channel / 8] & (1 << (channel & 0x07))) > 0;
+}
+
+
+//////////////////////////////////////////////////
+//
+//  WRITE
+//
+//  MAX speed single device 30 MHz
+//             multi device 15 MHz   CHECK TODO
+void TLC5917::write()
+{
+  write(_channels);
+}
+
+
+void TLC5917::write(int chan)
+{
+  if (chan > _channels) chan = _channels;
+  if (chan < 0) return;
+
+#if defined(ARDUINO_ARCH_AVR) || defined(ARDUINO_ARCH_MEGAAVR)
+
+  //  register level optimized AVR
+  uint8_t port     = digitalPinToPort(_data);
+  volatile uint8_t *_dataOutRegister = portOutputRegister(port);
+  uint8_t outmask1 = digitalPinToBitMask(_data);
+  uint8_t outmask2 = ~outmask1;
+
+  port             = digitalPinToPort(_clock);
+  volatile uint8_t *_clockRegister = portOutputRegister(port);
+  uint8_t cbmask1  = digitalPinToBitMask(_clock);
+  uint8_t cbmask2  = ~cbmask1;
+
+  for (int channel = chan - 1; channel >= 0; channel--)
+  {
+    for (uint8_t mask = 0x80;  mask; mask >>= 1)
+    {
+      *_clockRegister &= cbmask2;
+      if (_buffer[channel] & mask)
+      {
+        *_dataOutRegister |= outmask1;
+      }
+      else
+      {
+        *_dataOutRegister &= outmask2;
+      }
+      *_clockRegister |= cbmask1;
+    }
+  }
+  *_clockRegister &= cbmask2;
+
+#else
+
+  //  also write when blank == LOW
+  //       to "preload the registers"
+  //  local variables to maximize speed.
+  uint8_t _clk = _clock;
+  uint8_t _dat = _data;
+
+  for (int channel = chan - 1; channel >= 0; channel--)
+  {
+    for (uint8_t mask = 0x80;  mask; mask >>= 1)
+    {
+      digitalWrite(_clk, LOW);
+      digitalWrite(_dat, _buffer[channel] & mask ? HIGH : LOW);
+      digitalWrite(_clk, HIGH);
+    }
+  }
+  digitalWrite(_clk, LOW);
+
+#endif
+
+  //  pulse latch to hold the signals
+  digitalWrite(_le, HIGH);
+  digitalWrite(_le, LOW);
+}
+
+
+//////////////////////////////////////////////////
+//
+//  ENABLE
+//
+void TLC5917::enable()
+{
+  digitalWrite(_oe, LOW);
+}
+
+
+void TLC5917::disable()
+{
+  digitalWrite(_oe, HIGH);
+}
+
+
+bool TLC5917::isEnabled()
+{
+  return (digitalRead(_oe) == LOW);
+}
+
+
+//////////////////////////////////////////////////
+//
+//  CONFIGURATION
+//
+//  NOT OPTIMIZED
+//
+//  Page 19
+void TLC5917::setCurrentAdjustMode()
+{
+  digitalWrite(_le, LOW);
+  digitalWrite(_oe, HIGH);
+
+  digitalWrite(_clock, HIGH);
+  digitalWrite(_clock, LOW);
+
+  digitalWrite(_oe, LOW);
+  digitalWrite(_clock, HIGH);
+  digitalWrite(_clock, LOW);
+
+  digitalWrite(_oe, HIGH);
+  digitalWrite(_clock, HIGH);
+  digitalWrite(_clock, LOW);
+
+  digitalWrite(_le, HIGH);
+  digitalWrite(_clock, HIGH);
+  digitalWrite(_clock, LOW);
+
+  digitalWrite(_le, LOW);
+  digitalWrite(_clock, HIGH);
+  digitalWrite(_clock, LOW);
+}
+
+
+//  Page 19
+void TLC5917::setNormalMode()
+{
+  digitalWrite(_le, LOW);
+  digitalWrite(_oe, HIGH);
+  digitalWrite(_clock, HIGH);
+  digitalWrite(_clock, LOW);
+
+  digitalWrite(_oe, LOW);
+  digitalWrite(_clock, HIGH);
+  digitalWrite(_clock, LOW);
+
+  digitalWrite(_oe, HIGH);
+  digitalWrite(_clock, HIGH);
+  digitalWrite(_clock, LOW);
+
+  digitalWrite(_clock, HIGH);
+  digitalWrite(_clock, LOW);
+
+  digitalWrite(_clock, HIGH);
+  digitalWrite(_clock, LOW);
+}
+
+
+void TLC5917::writeConfiguration(uint8_t config)
+{
+  uint8_t _clk = _clock;
+  uint8_t _dat = _data;
+  uint8_t _devices = _channels/8;
+
+  //  write same config to all devices
+  for (int i = 0; i < _devices; i++)
+  {
+    for (uint8_t mask = 0x80;  mask; mask >>= 1)
+    {
+      digitalWrite(_clk, LOW);
+      digitalWrite(_dat, config & mask ? HIGH : LOW);
+      digitalWrite(_clk, HIGH);
+    }
+    digitalWrite(_clk, LOW);
+  }
+
+  //  pulse latch to hold the signals in configuration register.
+  //  not exactly like Page 18 figure 13.
+  digitalWrite(_le, HIGH);
+  digitalWrite(_le, LOW);
+}
+
+
+
+/////////////////////////////////////////////////////////////
+//
+//  DERIVED CLASS
+//
+TLC5916::TLC5916(uint8_t clock, uint8_t data, uint8_t LE, uint8_t OE)
+        :TLC5917(clock, data, LE, OE)
+{
+  //  optional code, later.
+  //  type field?
+}
+
+
+TLC5916::TLC5916(int deviceCount, uint8_t clock, uint8_t data, uint8_t LE, uint8_t OE)
+        :TLC5917(deviceCount, clock, data, LE, OE)
+{
+}
+
+
+//  -- END OF FILE --
+
diff --git a/libraries/TLC5917/TLC5917.h b/libraries/TLC5917/TLC5917.h
new file mode 100644
index 00000000..7190dfb3
--- /dev/null
+++ b/libraries/TLC5917/TLC5917.h
@@ -0,0 +1,81 @@
+#pragma once
+//
+//    FILE: TLC5917.h
+//  AUTHOR: Rob Tillaart
+// VERSION: 0.1.0
+//    DATE: 2024-03-17
+// PURPOSE: Arduino library for TLC5917 8-Channel Constant-Current LED Sink Drivers.
+//     URL: https://github.com/RobTillaart/TLC5917
+
+
+#define TLC5917_LIB_VERSION             (F("0.1.0"))
+
+
+#include "Arduino.h"
+
+
+#define  TLC5917_OK                     0x0000
+#define  TLC5917_CHANNEL_ERROR          0xFFFF
+
+
+class TLC5917
+{
+public:
+  //  single device constructor
+  TLC5917(uint8_t clock, uint8_t data, uint8_t LE, uint8_t OE);
+  //  multi device constructor - for daisy chaining)
+  TLC5917(int deviceCount, uint8_t clock, uint8_t data, uint8_t LE, uint8_t OE);
+  virtual ~TLC5917();
+
+  bool     begin();
+  int      getChannels();
+
+  bool     setChannel(uint8_t channel, bool on);
+  bool     setChannel(uint8_t * array);  //  size must be deviceCount.
+  bool     setAll(bool on);
+  bool     getChannel(uint8_t channel);
+
+  //  write the buffer to the TLC5917 device(s).
+  void     write(int n);
+  void     write();
+
+  //  control the blank (OE) line.
+  void     enable();
+  void     disable();
+  bool     isEnabled();  //  returns status
+
+  //  configuration mode
+  //  TODO test if this works for single device.
+  //  TODO test if this works for cascaded devices.
+  void     setCurrentAdjustMode();
+  void     setNormalMode();
+  void     writeConfiguration(uint8_t config);
+
+
+protected:
+  int       _channels;
+  uint8_t * _buffer;
+  uint8_t   _clock;
+  uint8_t   _data;
+  uint8_t   _le;  //  latch enable
+  uint8_t   _oe;  //  output enable
+};
+
+
+/////////////////////////////////////////////////////////////
+//
+//  DERIVED CLASS
+//
+class TLC5916 : public TLC5917
+{
+public:
+  //  single device constructor
+  TLC5916(uint8_t clock, uint8_t data, uint8_t LE, uint8_t OE);
+  //  multi device constructor - for daisy chaining)
+  TLC5916(int deviceCount, uint8_t clock, uint8_t data, uint8_t LE, uint8_t OE);
+  virtual ~TLC5916() {};
+};
+
+
+//  -- END OF FILE --
+
diff --git a/libraries/TLC5917/examples/TLC5917_NightRider/TLC5917_NightRider.ino b/libraries/TLC5917/examples/TLC5917_NightRider/TLC5917_NightRider.ino
new file mode 100644
index 00000000..681fac93
--- /dev/null
+++ b/libraries/TLC5917/examples/TLC5917_NightRider/TLC5917_NightRider.ino
@@ -0,0 +1,58 @@
+//
+//      FILE: TLC5917_NightRider.ino
+//    AUTHOR: Rob Tillaart
+//   PURPOSE: demo
+//       URL: https://github.com/RobTillaart/TLC5917
+
+
+#include "TLC5917.h"
+
+int DEVICES = 1;
+const int CLOCK = 13;
+const int DATA  = 12;
+const int LATCH = 11;
+const int BLANK = 10;
+
+TLC5917 tlc(DEVICES, CLOCK, DATA, LATCH, BLANK);
+
+
+void setup()
+{
+  Serial.begin(115200);
+  Serial.println(__FILE__);
+  Serial.print("TLC5917_LIB_VERSION: \t");
+  Serial.println(TLC5917_LIB_VERSION);
+
+  tlc.begin();
+  tlc.enable();
+}
+
+
+void loop()
+{
+  static int pos = 0;
+  static int delta = 1;
+
+  //  clear;
+  for (int i = 0; i < tlc.getChannels(); i++)
+  {
+    tlc.setChannel(i, false);
+  }
+  tlc.write();
+
+  Serial.println(pos);
+  tlc.setChannel(pos, true);
+  tlc.write();
+  delay(100);
+  tlc.setChannel(pos, false);
+  tlc.write();
+
+  pos += delta;
+  if ((pos == 0) || (pos == tlc.getChannels())) 
+  {
+    delta = -delta;
+  }
+}
+
+
+//  -- END OF FILE --
diff --git a/libraries/TLC5917/examples/TLC5917_demo/TLC5917_demo.ino b/libraries/TLC5917/examples/TLC5917_demo/TLC5917_demo.ino
new file mode 100644
index 00000000..d38b806e
--- /dev/null
+++ b/libraries/TLC5917/examples/TLC5917_demo/TLC5917_demo.ino
@@ -0,0 +1,53 @@
+//
+//    FILE: TLC5917_demo.ino
+//  AUTHOR: Rob Tillaart
+// PURPOSE: demo
+//     URL: https://github.com/RobTillaart/TLC5917
+
+
+#include "TLC5917.h"
+
+const int DEVICES = 2;
+const int CLOCK = 13;
+const int DATA  = 12;
+const int LE    = 11;
+const int OE    = 10;
+
+TLC5917 tlc(DEVICES, CLOCK, DATA, LE, OE);
+
+
+void setup()
+{
+  Serial.begin(115200);
+  Serial.println(__FILE__);
+  Serial.print("TLC5917_LIB_VERSION: \t");
+  Serial.println(TLC5917_LIB_VERSION);
+
+  if (tlc.begin() == false)
+  {
+    Serial.println("error");
+    while(1);
+  }
+
+  Serial.print("Channels: ");
+  Serial.println(tlc.getChannels());
+
+  tlc.enable();
+
+  for (int ch = 0; ch < tlc.getChannels(); ch++)
+  {
+    tlc.setChannel(ch, true);
+    tlc.write();
+    delay(100);
+    tlc.setChannel(ch, false);
+  }
+  tlc.write();
+}
+
+
+void loop()
+{
+}
+
+
+//  -- END OF FILE --
diff --git a/libraries/TLC5917/examples/TLC5917_performance/TLC5917_performance.ino b/libraries/TLC5917/examples/TLC5917_performance/TLC5917_performance.ino
new file mode 100644
index 00000000..78a1dc4c
--- /dev/null
+++ b/libraries/TLC5917/examples/TLC5917_performance/TLC5917_performance.ino
@@ -0,0 +1,95 @@
+//
+//    FILE: TLC5917_performance.ino
+//  AUTHOR: Rob Tillaart
+// PURPOSE: test performance main functions.
+//     URL: https://github.com/RobTillaart/TLC5917
+
+
+#include "TLC5917.h"
+
+const int DEVICES = 100;
+const int CLOCK = 13;
+const int DATA  = 12;
+const int LATCH = 11;
+const int BLANK = 10;
+
+TLC5916 tlc(DEVICES, CLOCK, DATA, LATCH, BLANK);
+
+uint32_t start, stop;
+
+
+void setup()
+{
+  Serial.begin(115200);
+  Serial.println(__FILE__);
+  Serial.print("TLC5917_LIB_VERSION: \t");
+  Serial.println(TLC5917_LIB_VERSION);
+
+  if (tlc.begin() == false)
+  {
+    Serial.println("Error");
+    while (1);
+  }
+
+  Serial.print("Channels:\t\t");
+  Serial.println(tlc.getChannels());
+
+  tlc.enable();
+
+  testSetChannel();
+  testWrite();
+
+  Serial.println("\nDone...");
+}
+
+
+void loop()
+{
+}
+
+
+void testSetChannel()
+{
+  delay(100);
+  int channels = tlc.getChannels();
+  start = micros();
+  for (int channel = 0; channel < channels; channel++)
+  {
+    tlc.setChannel(channel, true);
+  }
+  stop = micros();
+  Serial.print("SETCHANNEL TRUE:\t");
+  Serial.println(stop - start);
+  delay(100);
+
+  start = micros();
+  for (int channel = 0; channel < channels; channel++)
+  {
+    tlc.setChannel(channel, false);
+  }
+  stop = micros();
+  Serial.print("SETCHANNEL FALSE:\t");
+  Serial.println(stop - start);
+  delay(100);
+
+  start = micros();
+  tlc.setAll(true);
+  stop = micros();
+  Serial.print("SETALL TRUE:\t\t");
+  Serial.println(stop - start);
+  delay(100);
+}
+
+
+void testWrite()
+{
+  delay(100);
+  start = micros();
+  tlc.write();
+  stop = micros();
+  Serial.print("WRITE:\t\t\t");
+  Serial.println(stop - start);
+}
+
+
+//  -- END OF FILE --
diff --git a/libraries/TLC5917/examples/TLC5917_performance/performance_0.1.0.txt b/libraries/TLC5917/examples/TLC5917_performance/performance_0.1.0.txt
new file mode 100644
index 00000000..b22a038c
--- /dev/null
+++ b/libraries/TLC5917/examples/TLC5917_performance/performance_0.1.0.txt
@@ -0,0 +1,24 @@
+Arduino UNO
+IDE: 1.8.19
+
+(AVR optimized write() on UNO)
+TLC5917_performance\TLC5917_performance.ino
+TLC5917_LIB_VERSION: 	0.1.0
+Channels:		800
+SETCHANNEL TRUE:	9908
+SETCHANNEL FALSE:	9960
+SETALL TRUE:		228
+WRITE:			14300
+
+Done...
+
+
+(default write() on UNO for reference)
+TLC5917_LIB_VERSION: 	0.1.0
+Channels:		800
+SETCHANNEL TRUE:	9908
+SETCHANNEL FALSE:	9960
+SETALL TRUE:		228
+WRITE:			75364
+
+Done...
diff --git a/libraries/TLC5917/keywords.txt b/libraries/TLC5917/keywords.txt
new file mode 100644
index 00000000..d18faa1c
--- /dev/null
+++ b/libraries/TLC5917/keywords.txt
@@ -0,0 +1,36 @@
+# Syntax Colouring Map For TLC5917
+
+
+# Data types (KEYWORD1)
+TLC5916	KEYWORD1
+TLC5917	KEYWORD1
+
+
+# Methods and Functions (KEYWORD2)
+begin	KEYWORD2
+getChannels	KEYWORD2
+
+setChannel	KEYWORD2
+setAll	KEYWORD2
+getChannel	KEYWORD2
+
+write	KEYWORD2
+
+enable	KEYWORD2
+disable	KEYWORD2
+isEnabled	KEYWORD2
+
+setCurrentAdjustMode	KEYWORD2
+setNormalMode	KEYWORD2
+writeConfiguration	KEYWORD2
+
+
+# Instances (KEYWORD2)
+
+
+# Constants (LITERAL1)
+TLC5917_LIB_VERSION	LITERAL1
+
+TLC5917_OK	LITERAL1
+TLC5917_CHANNEL_ERROR	LITERAL1
+
diff --git a/libraries/TLC5917/library.json b/libraries/TLC5917/library.json
new file mode 100644
index 00000000..6681f423
--- /dev/null
+++ b/libraries/TLC5917/library.json
@@ -0,0 +1,23 @@
+{
+  "name": "TLC5917",
+  "keywords": "TLC5916, TLC5917",
+  "description": "Arduino library for TLC5917 8-Channel Constant-Current LED Sink Drivers.",
+  "authors":
+  [
+    {
+      "name": "Rob Tillaart",
+      "email": "Rob.Tillaart@gmail.com",
+      "maintainer": true
+    }
+  ],
+  "repository":
+  {
+    "type": "git",
+    "url": "https://github.com/RobTillaart/TLC5917.git"
+  },
+  "version": "0.1.0",
+  "license": "MIT",
+  "frameworks": "*",
+  "platforms": "*",
+  "headers": "TLC5917.h"
+}
diff --git a/libraries/TLC5917/library.properties b/libraries/TLC5917/library.properties
new file mode 100644
index 00000000..37926424
--- /dev/null
+++ b/libraries/TLC5917/library.properties
@@ -0,0 +1,11 @@
+name=TLC5917
+version=0.1.0
+author=Rob Tillaart <rob.tillaart@gmail.com>
+maintainer=Rob Tillaart <rob.tillaart@gmail.com>
+sentence=Arduino library for TLC5917 8-Channel Constant-Current LED Sink Drivers.
+paragraph=TLC5916
+category=Sensors
+url=https://github.com/RobTillaart/TLC5917
+architectures=*
+includes=TLC5917.h
+depends=
diff --git a/libraries/TLC5917/test/unit_test_001.cpp b/libraries/TLC5917/test/unit_test_001.cpp
new file mode 100644
index 00000000..89e78d6f
--- /dev/null
+++ b/libraries/TLC5917/test/unit_test_001.cpp
@@ -0,0 +1,70 @@
+//
+//    FILE: unit_test_001.cpp
+//  AUTHOR: Rob Tillaart
+//    DATE: 2024-03-17
+// PURPOSE: unit tests for the TLC5917 library.
+//          https://github.com/RobTillaart/TLC5917
+//          https://github.com/Arduino-CI/arduino_ci/blob/master/REFERENCE.md
+//
+
+// supported assertions
+// ----------------------------
+// assertEqual(expected, actual);               // a == b
+// assertNotEqual(unwanted, actual);            // a != b
+// assertComparativeEquivalent(expected, actual);    // abs(a - b) == 0 or (!(a > b) && !(a < b))
+// assertComparativeNotEquivalent(unwanted, actual); // abs(a - b) > 0  or ((a > b) || (a < b))
+// assertLess(upperBound, actual);              // a < b
+// assertMore(lowerBound, actual);              // a > b
+// assertLessOrEqual(upperBound, actual);       // a <= b
+// assertMoreOrEqual(lowerBound, actual);       // a >= b
+// assertTrue(actual);
+// assertFalse(actual);
+// assertNull(actual);
+
+// // special cases for floats
+// assertEqualFloat(expected, actual, epsilon);    // fabs(a - b) <= epsilon
+// assertNotEqualFloat(unwanted, actual, epsilon); // fabs(a - b) >= epsilon
+// assertInfinity(actual);                         // isinf(a)
+// assertNotInfinity(actual);                      // !isinf(a)
+// assertNAN(arg);                                 // isnan(a)
+// assertNotNAN(arg);                              // !isnan(a)
+
+
+#include <ArduinoUnitTests.h>
+
+
+#include "Arduino.h"
+#include "TLC5917.h"
+
+
+
+unittest_setup()
+{
+  fprintf(stderr, "TLC5917_LIB_VERSION: %s\n", (char *) TLC5917_LIB_VERSION);
+}
+
+
+unittest_teardown()
+{
+}
+
+
+unittest(test_begin)
+{
+  TLC5917 tlc1(1, 13, 12, 11, 10);
+
+  assertTrue(tlc1.begin());
+  assertEqual(8, tlc1.getChannels());
+
+  TLC5917 tlc(21, 13, 12, 11, 10);
+
+  assertTrue(tlc.begin());
+  assertEqual(168, tlc.getChannels());
+}
+
+
+unittest_main()
+
+
+//  -- END OF FILE --
+