tag:blogger.com,1999:blog-18076623981979864782024-03-15T00:41:28.217+05:30Dilshan R Jayakody’s Web LogThis blog contains electronic, amateur radio, and embedded system projects, which I did during my free time. Unless otherwise noted, all the articles and projects described on this blog are based on my original designs. Dilshan Jayakodyhttp://www.blogger.com/profile/04879320865396389381noreply@blogger.comBlogger244125tag:blogger.com,1999:blog-1807662398197986478.post-70711358828676094242023-06-30T19:04:00.001+05:302023-06-30T19:07:52.043+05:30Echo Generator for MicrophonesThis project is about a single-channel microphone echo generator circuit. This circuit builds around the Holtek HT8970 echo effect generator IC. It offers complete control of the echo effect by providing delay, mix, and output level adjustments. HT8970 is an echo/surround sound effect generator IC with 20Kb SRAM. It also contains the built-in VCO stage, AD, and DA converters. The chip costs Dilshan Jayakodyhttp://www.blogger.com/profile/04879320865396389381noreply@blogger.com0tag:blogger.com,1999:blog-1807662398197986478.post-69187393481272405252023-03-29T03:18:00.001+05:302023-03-29T04:02:56.384+05:30Universal HD44780 LCD interfaceYALI (Yet Another LCD Interface) is an open-source project to provide a universal interface to drive the popular Hitachi HD44780 LCD controller. This module supports 3.3V and 5V MCUs and hardware development platforms, including Arduino, STM32, PIC, and ESP8266.YALI hardware module.The hardware module of this project consists of a 74HCT08 CMOS AND gate and a 74HC595 8-bit serial-in, parallel-out Dilshan Jayakodyhttp://www.blogger.com/profile/04879320865396389381noreply@blogger.com0tag:blogger.com,1999:blog-1807662398197986478.post-9714716739534141382022-12-31T05:30:00.002+05:302022-12-31T07:09:39.249+05:306-channel speaker selectorAt the beginning of 2018, we developed the first version of the 6-channel speaker selector using PIC16F88 MCU and ULN2803 Darlington transistor array. In this new design, we redesign it with low-cost MCU and Darlington transistor arrays. This design also provides the same functionality as the 6-channel speaker selector switch we designed earlier. This new speaker selector uses STC15W201 MCU. ThisDilshan Jayakodyhttp://www.blogger.com/profile/04879320865396389381noreply@blogger.com0tag:blogger.com,1999:blog-1807662398197986478.post-9718009548227198322022-10-25T02:36:00.000+05:302022-10-25T02:36:09.206+05:305.1 channel analog audio processorIn this project, we developed a 5.1-channel analog audio processor using PT2322 IC. PT2322 is an inexpensive analog audio processor introduced by Princeton Technology Corporation. It contains 6-channel individual channel attenuators, a 3-way tone control system for front-end speakers, and a 3D audio simulation system. Assembled 5.1-channel audio processing board.In this design, we combine Dilshan Jayakodyhttp://www.blogger.com/profile/04879320865396389381noreply@blogger.com0tag:blogger.com,1999:blog-1807662398197986478.post-82855609074452482392022-09-12T12:25:00.001+05:302022-09-12T14:00:17.744+05:30Onkyo PE-C50 stereo graphic equalizer repairA few months ago, I received this Onkyo PE-C50 stereo graphic equalizer from a friend because it was not working. He gave me this equalizer for free because he was planning to discard it due to some problems with its controls.Front panel of the Onkyo PE-C50.The Onkyo PE-C50 is a vintage, 7-channel, stereo digital graphic equalizer. This unit is manufactured in Japan and operates on 110V AC power Dilshan Jayakodyhttp://www.blogger.com/profile/04879320865396389381noreply@blogger.com0tag:blogger.com,1999:blog-1807662398197986478.post-26305815676166160132022-06-19T06:24:00.003+05:302022-06-22T08:42:10.261+05:30Virtual electronic finderscope for the StellariumStarPointer is a virtual electronic finderscope for astronomical telescopes. This device works with Stellarium and helps the observer identify objects in the sky. Prototype version of the StarPointer sensor kit.This unit can be attached to the telescope without modifications and connects with the computer through the USB port. The StarPointer uses a few onboard sensors to determine its angleDilshan Jayakodyhttp://www.blogger.com/profile/04879320865396389381noreply@blogger.com0tag:blogger.com,1999:blog-1807662398197986478.post-7145474338743032842022-05-20T21:42:00.000+05:302022-05-20T21:42:10.723+05:30Portable Image File (PIF) library for Lazarus and DelphiPortable Image File (PIF) is an embedded-systems friendly, bitmap-like image format with ease of use and small size. This image format develops by the gfcwfzkm (aka Pascal) for low-end embedded systems. The file format and PIF's original implementation are available at https://github.com/gfcwfzkm/PIF-Image-Format.In this project, I developed an open-source library for the above file format to getDilshan Jayakodyhttp://www.blogger.com/profile/04879320865396389381noreply@blogger.com0tag:blogger.com,1999:blog-1807662398197986478.post-44236701466325398472022-05-14T06:10:00.003+05:302022-05-16T22:18:50.765+05:30Experimental narrowband FM receiver for 2-meter bandThis project is about MC3362 and ADF4351 based modularized, 2-meter narrow band FM receiver. In this design, the receiver splits into three modules as RF preamplifier, MC3362 tuner, and ADF4351 oscillator. The RF preamplifier builts around BF900 dual-gate MOSFET. The tuner stage builts using the popular MC3362, low power narrowband FM receiver IC. For the oscillator, we use the ADF4351 DDS RF Dilshan Jayakodyhttp://www.blogger.com/profile/04879320865396389381noreply@blogger.com0tag:blogger.com,1999:blog-1807662398197986478.post-13627265553211257442022-03-20T05:46:00.000+05:302022-03-20T05:46:30.253+05:30Wireless Call BellThis project is about a wireless musical call bell, which I designed to meet some of my friend's requirements. This circuit design uses only the 4000 series CMOS logical ICs, NE555, UM66, and TDA7233 audio amplifier IC. For the remote control, we use a 433MHz 4-channel remote control module. This circuit is designed to work continuously with a low-power external 5V power supply.Prototype version Dilshan Jayakodyhttp://www.blogger.com/profile/04879320865396389381noreply@blogger.com0tag:blogger.com,1999:blog-1807662398197986478.post-7688954456218510492022-02-16T19:33:00.000+05:302022-02-16T19:33:30.244+05:30Infrared remote control clone utilityIR Clone is an open-source IR remote control analyzer tool. This utility can analyze any IR remote control that modulates the IR signal with a 38kHz carrier signal. This utility has an option to store and retrieve up to 16 IR signals. In addition, it has PC software to analyze and edit captured IR signals.The hardware component of this analyzer is built around the STM8S003F3 MCU. It has 24LC32 Dilshan Jayakodyhttp://www.blogger.com/profile/04879320865396389381noreply@blogger.com0tag:blogger.com,1999:blog-1807662398197986478.post-32223780617665020512021-11-26T03:46:00.001+05:302021-11-26T04:02:06.196+05:30TPA3001D1 Power AmplifierRecently we looked for a replacement class-D power amplifier to replace my old TDA2030 power amplifier build. While searching for a suitable power amplifier IC, we found TPA3001D1 from the local market. This IC is a slightly older 20W Class-D power amplifier manufactured by Texas Instruments. At the time of this writing, it is priced at LKR 180 (0.89 USD) in the local market and is still Dilshan Jayakodyhttp://www.blogger.com/profile/04879320865396389381noreply@blogger.com0tag:blogger.com,1999:blog-1807662398197986478.post-19362226138927915192021-11-16T05:21:00.002+05:302021-11-16T05:22:45.397+05:30STM8S005C6T6 Ethernet development boardIn this project, we built an STM8S005C6T6 based Ethernet development board for our IoT experiments. This development board consists of ENC28J60, 10BASE-T stand-alone Ethernet controller, CH340G, USB serial interface, 2 LED indicators, and passive buzzer unit.The firmware framework for this development board has been developed using SDCC. To enable IPv4 support, we convert the EtherCard driver, Dilshan Jayakodyhttp://www.blogger.com/profile/04879320865396389381noreply@blogger.com0tag:blogger.com,1999:blog-1807662398197986478.post-42046128548359902362021-11-01T19:27:00.000+05:302021-11-01T19:27:37.335+05:305.1 channel preamplifierThis project introduces a digitally controlled 5.1 channel audio preamplifier system. This amplifier is specifically designed to increase the gain of the multi-channel PC sound cards.
The main reason for building this amplifier is the limited gain received from the ASUS Xonar AE sound card with the Creative Inspire T6300, 5.1 surround speaker system. Before switching to this soundcard, we had a Dilshan Jayakodyhttp://www.blogger.com/profile/04879320865396389381noreply@blogger.com0tag:blogger.com,1999:blog-1807662398197986478.post-6062956216979491342021-10-07T22:19:00.000+05:302021-10-07T22:19:04.642+05:30Corsair VS550 Power Supply RepairA few months ago, our AMD Ryzen™ 5 computer started giving some startup issues. At first, this problem happened randomly, and then it started happening at every bootup.The symptom is that if the computer shuts down after a boot, it will not start on the next power cycle(s). If we turn it off for 30 or 45 minutes and then turn it on, it will start working without any problems. This problem did notDilshan Jayakodyhttp://www.blogger.com/profile/04879320865396389381noreply@blogger.com0tag:blogger.com,1999:blog-1807662398197986478.post-68733042556429979992021-10-05T20:03:00.001+05:302021-10-06T05:45:03.608+05:30Arduino superheterodyne receiverIn this project, we extend the shortwave superheterodyne receiver we developed a few years ago. Like the previous design, this receiver operates on the traditional superheterodyne principle. In this upgrade, we enhanced the local oscillator with Si5351 clock generator module and Arduino control circuit. Compared to the old design, this new receiver uses an improved version of an intermediateDilshan Jayakodyhttp://www.blogger.com/profile/04879320865396389381noreply@blogger.com0tag:blogger.com,1999:blog-1807662398197986478.post-69591087427354966152021-09-20T09:10:00.002+05:302021-09-29T14:42:21.611+05:30Active subwoofer filter circuitThis active subwoofer filter system provides the frequencies required to run the subwoofer within its limits. The purpose of this unit is to prevent the subwoofer speaker or circuit from overloading at unsupported frequencies. This approach can ensure the safety of the subwoofer speaker or driver circuit.This system consists of TL074 based active lowpass filter, highpass filter, and preamplifier Dilshan Jayakodyhttp://www.blogger.com/profile/04879320865396389381noreply@blogger.com0tag:blogger.com,1999:blog-1807662398197986478.post-5046813465043951352021-09-06T09:14:00.004+05:302021-09-29T14:37:28.931+05:30FM Radio add-on for Raspberry PiThe QN8035 is a stereo FM radio receiver launched by the Quintic Corporation. Compared to other popular digital FM tuners (RDA5807, TEA5767, etc.), this tuner does not seem to be as popular among the DIY community. As we have seen, the biggest problem with this IC is the lack of information. During our initial search, we came across some details about this IC. Much of that information was Dilshan Jayakodyhttp://www.blogger.com/profile/04879320865396389381noreply@blogger.com0tag:blogger.com,1999:blog-1807662398197986478.post-10699517357879388012021-08-24T18:45:00.003+05:302021-08-24T18:47:21.792+05:30Universal logic probeThese days good quality oscilloscope is not an expensive instrument and, we can see it in most workbenches. With the advancement of oscilloscopes, simple testing tools such as logic probes are not as popular these days. However, if the oscilloscope or logic analyzer was out of reach, the logic probe is a handy instrument to check digital circuits. Also, in some cases, a logic probe is an Dilshan Jayakodyhttp://www.blogger.com/profile/04879320865396389381noreply@blogger.com0tag:blogger.com,1999:blog-1807662398197986478.post-1163453070567606012021-08-13T09:29:00.000+05:302021-08-13T09:29:04.189+05:30Arduino telephone caller ID unitCLI, also known as Caller ID and calling number delivery (CND), is a service offered by the telephone service provider to customers to obtain the calling party number and date/time of the call. The service activation and information format of CLI are different from telephone network operator to operator.CLI display unit - minimum test setupIn this project, we will create a small Caller ID decoderDilshan Jayakodyhttp://www.blogger.com/profile/04879320865396389381noreply@blogger.com0tag:blogger.com,1999:blog-1807662398197986478.post-87990750699334275252021-07-20T01:29:00.000+05:302021-07-20T01:29:19.548+05:30TDA7052A - DIY miniature amplifierTDA7052A is an audio power amplifier designed for use in low voltage battery-powered equipment. Compare with the popular LM386, TDA7052A is not so popular among DIY electronic enthusiasts. Final view of the finished amplifier with speaker. Using the Bridge Tied Load principal, this IC delivers an output power of 1.2W into an 8Ω load with, 6V power supply. The most striking featureDilshan Jayakodyhttp://www.blogger.com/profile/04879320865396389381noreply@blogger.com0tag:blogger.com,1999:blog-1807662398197986478.post-7622788512585467812021-06-27T17:27:00.002+05:302021-06-28T08:34:18.900+05:3012V Uninterruptible Power SupplyThis 12V uninterruptible power supply initially designs to drive my fiber optic modem/router. The key reason to build this power supply is to get continuous internet and phone connection during power failures. Core components of this power supply are a constant voltage charger, 12V DC power supply, AC line monitoring unit, and 12V high capacity sealed lead-acid battery. The entire system designs Dilshan Jayakodyhttp://www.blogger.com/profile/04879320865396389381noreply@blogger.com2tag:blogger.com,1999:blog-1807662398197986478.post-38144196018320772542021-05-23T09:58:00.000+05:302021-05-23T09:58:34.901+05:30STM8S001J3 based Programmable timer moduleProgrammable timer lite is a miniature, USB programmable timer module. This module can handle more than 100 alarm configurations and trigger the output channel based on the programmed conditions. The timer module can program using SRIKit's Timer Controller software. All the timer configurations are store in the EEPROM to prevent the loss of data during power failures.Programmable timer module.We Dilshan Jayakodyhttp://www.blogger.com/profile/04879320865396389381noreply@blogger.com2tag:blogger.com,1999:blog-1807662398197986478.post-27619051076500056042021-05-10T19:10:00.001+05:302021-05-10T19:16:29.463+05:30SD card extension for OpenFAT libraryOpenFAT is an open-source FAT file system implementation for embedded systems. The original library is well written and documented. We recently came across this library while looking for a LibOpenCM3 support SD/MMC FAT file system library. At the initial review, we notice that this library does not maintain for the last ten years. Also, it does not provide support to the latest SD card Dilshan Jayakodyhttp://www.blogger.com/profile/04879320865396389381noreply@blogger.com0tag:blogger.com,1999:blog-1807662398197986478.post-20639573305339376202021-04-27T21:20:00.000+05:302021-04-27T21:20:08.305+05:30NTP based digital clock panel driverThis project introduces an open-source, ATmega328 based, configurable NTP clock with a 2.3-inch, 7-segment display driver. This clock automatically obtains time from the configured NTP server and updates the date and time of the built-in RTC (real-time clock). If the connection to the NTP server is lost, the clock continues to run using its built-in RTC.Finished NTP clock driver PCB.All the Dilshan Jayakodyhttp://www.blogger.com/profile/04879320865396389381noreply@blogger.com0tag:blogger.com,1999:blog-1807662398197986478.post-19503198669961580352021-04-18T09:34:00.000+05:302021-04-18T09:34:15.518+05:30FM stereo receiver moduleThis is an RDA5807M based FM stereo radio module. This module is designed to replace old, low-voltage, analog FM stereo radio receiver modules. Like many digital receivers, this module also got auto scanning, station memory, and digital volume control. This module can driver using 5V to 9V DC power source.FM stereo receiver module with seven-segment display unit.The frequency range of the Dilshan Jayakodyhttp://www.blogger.com/profile/04879320865396389381noreply@blogger.com0