KT0915

This is an Arduino Library to control the KT0915 DSP receiver from KTMicro

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PU2CLR KT0915 Arduino Library

This is an Arduino Library to control the KT0915 DSP receiver from KTMicro. The KT0915 is an integrated circuit that provides full band receiver on FM and AM (MW/SW/LW).

Copyright (c) 2020 Ricardo Lima Caratti.

Contact: pu2clr@gmail.com.

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Contents

  1. Preface
  2. Your support is important
  3. Library Features
  4. MIT License
  5. Library Installation
  6. About KT0915 DSP radio
  7. SCHEMATIC
  8. API Documentation
  9. Source code - Examples
  10. Videos
  11. References

Preface

The KT0915 is a full band AM (LW, MW and SW) and FM DSP receiver that can provide you a easy way to build a high quality radio with low cost. This device, will surprise hobbyists and experimenters with its simplicity.

In this document you will see Arduino source codes, schematics, examples and tips to help you to build a receiver based on Arduino board and the KT0915 device. The project and examples shown here do not intend to be a real receiver for exigent listener. However, it is possible to start with it and after add some improvements. On the other hand, with the simple circuits shown here, the experimenter may be surprised with its performance.


Presentation video

PU2CLR KT0915 Arduino LIbrary - AM (MW and SW) and FM receiver with KT0915



Tutorial - AM / FM with KT0915 receiver and PU2CLR KT0915 Arduino Library

Video Tutorial

See also

More Arduino Projects developed by author

Your support is important

If you would like to support this library development, consider joining this project via Github. Alternatively, make suggestions on new features and report errors if you find them. Thank you!

Library Features

This library uses the I²C communication protocol and implements most of the functions offered by the KT0915 (BROADCAST AM / FM / SW / LW RECEIVER).

The main features of this library are listed below.

  1. Open Source. It is free. You can use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software. See MIT License to know more;
  2. Built based on KT0915 stereo FM / TV / MW / SW / LW digital tuning radio;
  3. C++ Language and Object-oriented programming. You can easily extend the AKC695X class by adding more functionalities;
  4. Available on Arduino IDE (via Manage Libraries). Easy to install and use;
  5. Cross-platform. You can compile and run this library on most of board available on Arduino IDE (Examples: ATtiny85, boards based on ATmega328 and ATmega-32u4, ATmega2560, ARM Cortex, STM32, Arduino DUE, ESP32 and more);
  6. Simplifies projects based on KT0915 IC;
  7. Support to 32.768KHz and external reference clock;
  8. Support to audio controlled by the MCU (Arduino) or potentiometer;
  9. Real time FM stereo or mono indicator;
  10. FM stereo or mono selecting;
  11. Real time signal level reading;
  12. Real time AM and FM carrier to noise ratio information (dB).
  13. Bandwidth selection for AM;
  14. Custom band support;
  15. More than 40 functions implemented.

MIT License

Copyright (c) 2019 Ricardo Lima Caratti

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 ARRANTIES 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.


Library Installation

You can install this library on your Arduino environment using different methods. The best ways to do that are described below.

Installing via Arduino IDE

// TODO

About KT0915 DSP radio

According to “Monolithic Digital FM/MW/SW/LW Receiver Radio on a Chip(TM); KT0915” document from KTMicro, “the KT0915 is a fully integrated full band AM/FM digital radio receiver IC with patented technologies that offer full band FM/MW/SW/LW functionality, high quality audio performance, simple design and low BOM cost. The direct frequency and volume control interface help custumers to maintain the classic looks of their existing products.

Thanks to the patented tuning technology, the receiver maintains good signal reception with short antenna. The chip consumes only 22mA current and can be powered by 2 AAA batteries. Another useful feature is that the volume and channel setup can be preserved in standby mode without external memories. KT0915 supports a wide range of reference clocks from 32.768KHz to 26MHz, hence can share system clocks with a varieties of MCUs further reducing the system BOM cost.

With high audio performance, fully integrated features and low BOM cost, KT0915 is ideal for various FM/MW/SW/LW applications and products”.

KT0915 features

  1. Worldwide full band FM/MW/SW/LW support FM: 32MHz-110MHz
    • FM: 32MHz-110MHz
    • MW: 500KHz-1710KHz
    • SW: 1.6MHz~32MHz
    • LW: 150KHz ~ 280KHz
  2. Fully integrated frequency synthesizer with no external component
  3. High Sensitivity
    • 1.6uVEMF for FM
    • 16uVEMF for AM
  4. High Fidelity
    • SNR (FM/AM): 60dB/55dB
    • THD: 0.3%
  5. Low supply voltage: 2.2V to 3.6V, can be supplied by 2 AAA batteries
  6. Automatic antenna tuning
  7. Adjustable AM channel filters (2k/4k/6KHz)
  8. Embedded FM SNR meter
  9. Fast seek/Tune
  10. Integrated stereo headphone driver I²C control interface for MCU
  11. Support traditional dial and digital key for frequency tuning and volume control
  12. Memorize channel and volume in standby mode
  13. Low Supply Current - 22mA (operating) <15uA (standby)
  14. Support both 32.768KHz and 38KHz crystal
  15. Support continuous reference frequency from 32.768KHz to 26MHz

Source: “Monolithic Digital FM/MW/SW/LW Receiver Radio on a Chip(TM); KT0915” document from KTMicro

KT0915 Pinout

Pin Number Pin Name Description
1 CH Channel Adjustment. Used to deal with mechanical tune option
2 DVSS Digital Ground
3 ROUT Righ channel audio output
4 LOUT Left channel audio output
5 AVSS Analog ground
6 AVDD Power Supply
7 XI/RCLK Crystal input or reference clock input setup
8 XO Crystal Output
9 ENABLE Chip enable. Tied to an internal 600kohm pull down resistor
10 AMINN AM RF negative input
11 AMINP AM RF positive input
12 RFINP FM RF input
13 RFGND RF ground
14 SCL SCL of I²C bus. Tied to an internal 47kohm pull-up resistor
15 SDA SDA of I²C bus. Tied to an internal 47kohm pull-up resistor
16 VOL Volume adjustment. Used to deal with mechanical volume control

KT0915 SSOP16L package

KT0915 SSOP16L package

About the Pin 1 (CH) and Pin 16 (VOL)

The KT0915 can be configured to deal with mechanical tuning via a variable resistors. For example, you can use a variable resistor to control the audio volume and another to tuninig the receiver. This resource is enabled by setting the internal register GPIOCFG (Address 0x1D) of the device. The dial can be a variable resistor with the tap connected to CH and VOL as well. The divided voltage at the tap is processed by the internal KT0915 analog to digital converter (ADC). Finally, the converted datas are stored into the internal registers of the KT0915 device.

By default, this library the tune and volume are conttrolled by the MCU (Arduino). However, you can sets the mechanical feature by calling setTuneDialModeOn and setVolumeDialModeOn. See API Documentation.

See KT0915 - Monolithic Digital FM/MW/SW/LW ReceiverRadio-on-a-Chip™; pages: 8, 9, 10 and 20.

SCHEMATIC

You can use the Typical Application Circuit suggested by the KTMicro. This circuit can be found in the document KT0915-Monolithic Digital FM/MW/SW/LW Receiver Radio-on-a-Chip. The main porpuse of this prototype below is testing de KT0915 Arduino Library. It does not intend to be a real radio for exigent listener. However, it is possible to start with it and after include some devices to improve, for example, its sensibility beyond other desired features. The schematic below does not use the ferrite antenna as suggested by KTMicro and no front-en as well. See KT0915 - Monolithic Digital FM/MW/SW/LW ReceiverRadio-on-a-Chip™; page 24.


Picture Schematic


The KT0915 is a 3.3V part. If you are not using a 3.3V version of Arduino, you have to use a kind of 5V to 3.3V bidirectional converter. It is important to say that just power the KT0915 device with 3.3V from Arduino board is not enough. You have to be aware that the Arduino that operates with 5V, the digital pins and the I²C bus will send 5V signals to the KT0915 device. That configuration can make the system unstable or damage the device.

Parts

The table below shows the component parts used to build the receiver prototype based on KT0915


Components Value Description
C1 10uF Ceramic or tantalum capacitor
C2 100nF Ceramic or tantalum capacitor
C3, C4 22pF Supply decoupling capacitor - Ceramic or tantalum capacitor
C5, C6 10uF Electrolytic or tantalum capacitor
C7 100nF AC coupling capacitor
Q1 32.768KHz Crystal
R1, R2 10K I²C buss Pull up ristors
Arduino Pro Mini 3.3V 8Mhz
KT0915 DSP FM and AM receiver
VCC 3.3V Baterry


Photos

Photo 01


Photo 02


Photo 03

Videos

PU2CLR KT0915 Arduino LIbrary - First Test PU2CLR KT0915 Arduino Library - Sound testing

References