Micro-controller and EEPROM memory integrated circuits

In 1985 Nagendra started his Bachelor of Engineering degree at the Adhiparasakthi Engineering College, Chennai. Later when he started learning digital electronics in second year of his study, he learnt about memory devices. This EPROM (erasable programmable memory) with the ability to program and erase the content intrigued his thoughts on various applications that he can use these memory devices.

Initial Design of DGTAL – TALOMETER

One application that came to his mind was to store each pattern of the thirty-five Carnatic Soolathi Tāla and play the pattern when the user selects that Tāla. So, he built the first version of Talometer using a M2764A EPROM from ST Microelectronics. He then designed the circuit and programmed the EPROM to play four Tāla (Adhi, Rupakam, Ata and Eka) and using the typical telephone key pad, one could select the Jaathi and the Tāla to turn on the LEDs which indicate the hand gestures of putting a Tāla.

During his engineering college days, he also built an electronic Tanpura using NE555 ICs to generate string sound with attack and decay circuits. however, the quality of sound was not quite comparable to realistic Tanpura sound.

After graduation he moved to New Zealand and with work and family commitments, hobby electronics was put on hold. Then in 1994 he moved to Singapore to work at Singapore Polytechnic as a lecturer and used the opportunity to work on many student projects in the areas of embedded controllers and medical instrumentation. He worked on a few music synthesizer ICs to generate true string sound, but could not perfect the sound quality.

In 2009 he had some spare time to learn the Flute from his father Dr. Gangadharan, who went to New Zealand for a holiday after he was displaced by the war in Vanni, Sri Lanka. Nagendra searched the Google to buy a good electronic Tanpura and an electronic Talometer, hoping that by this time (over 23 years) someone would have perfected these electronic instruments.

The Talometer that he borrowed from his friend was so difficult to set it up and couldn’t play many of the common Carnatic Tāla. Even going through the user manual for several hours, he couldn’t figure out. The electronic Tanpura he bought failed after two months, he bought another two electronic Tanpura and they too didn’t last long. Frustrated with the quality of these instruments and user unfriendliness, Nagendra decided to make his own Talometer for his own use – The 1986 Talometer idea was resurrected. Unfortunately, in 1994 the very first model of Talometer that he built was destroyed by the invading forces in Sri Lanka.


With embedded programming skills under his belt, he built the second version of Talometer using the Atmel Atmega324P chip. He then named it DGTAL (in dedication to his father Dr Gangadharan TALometer – DGTAL). This version two could play 35 Soolathi Tāla with a single joy-stick navigation button. Family and Friends liked it so much that he built a few more of these units for them to test. He then received very good feedback and he decided to improve the display and the navigation buttons and built 10 more units of the improved version of DGTAL.

In 2012 Shashank Subramanyam visited Darwin, Australia to give a Flute recital. Then Nagendra had the opportunity to meet him and give a complementary unit to Shashank. Shashank was impressed with the design features and gave excellent feedback and encouragement to build more units. Shashank also requested Nagendra to include a realistic sounding Tanpura in this unit as he does not use the electronic Tanpura in his concerts due to its very poor sound quality. Following this, Nagendra incorporated most of Shashank’s suggestions and designed a professional version of DGTAL.

Tanpura Design

Nagendra is currently working on an acoustic Tanpura with metal strings that will be plucked by set of Robotic fingers to produce natural Tanpura sound. This Yarl Tanpura will have the shape of Yarl reflecting the company name he founded in 2012. Once Robotic fingering technique is perfected, this module can be mounted on to any traditional Tanpura to pluck the strings. Hopefully Shashank and other musicians will like the idea of bringing the traditional Tanpura back to the stage.

The following musicians have received the complementary unit of DGTAL and hope they use it to train their students with it to imprint the Laya. If you are keen to try using the DGTAL to train your students on the importance of Laya, please contact Yarl Technologies Pty Ltd.

  1. Dr Suresh Ramachandra
  2. Meena Ragu
  3. Dr Yogini Ratnasabapathy
  4. Lazar Thurakkal Sebastine
  5. Dr Bhagya Murthy
  6. Shashank Subramanyam
  7. Patri Satish Kumar
  8. Nellai Ravindran
  9. Neyveli Santhanagopalan
  10. Bombay Jayashri Ramnath
  11. Chitraveena N. Ravikiran
Versions of DGTAL Talometers

DGTAL Talometer

Standard Edition
Talometer Standard Edition
Premium Edition
Talometer Premium Edition

DGTAL Talometer Premium Edition and Talometer Standard Edition, Carnatic metronome, are marketed by Yarl Technology Pty Ltd since 2013 to the South Indian music community. An ancient Sanskrit verse once described the most important components of music as “Sruthi Maatha Laya Pitha” – the Tanpura is for maintaining the Sruthi; Talometer is for maintaining the Layam.

DGTAL Talometer is an invaluable accompaniment for Carnatic music teachers and students. This Talometer will help you unleash your creative music talent by playing Tāla tirelessly as you practice Carnatic music or aim to perfect your Layam in preparation for an upcoming music examination or stage performance.

When you practice with DGTAL Talometer, it will enable you to render any song with confidence and without ever missing a beat. DGTAL Talometer can play all 35 Tāla in Soolathi system in addition to the commonly used Chappu Tāla.

DGTAL Talometer front panel layout

Its elegant design, which mirrors the way one would put the Tāla by hand, makes it very intuitive to identify any Aksharam while you concentrate on rendering the song. The distinct colour of each lamp is visible at wide angles and all musicians on stage will be able to view it clearly. Furthermore, with very few buttons and a simple display layout showing the Tāla notation, DGTAL Talometer is a very user-friendly accompaniment.

The main difference between Premium and Standard Edition is the colour of the unit: Premium Edition come in a variety of colours (Burgundy, Noble Green, Midnight Blue, Charcoal Black). Standards Edition come in one colour Black.

DGTAL demo

DGTAL Talometer guiding Musicians from Panchamam Arts And Creations

Lazar Thurakkal Sebastine’s students playing Chaturasra Játhi Thriputa Thála Alangáram.


“Hi Nagendra, Thanks for sending me the DGTAL. The end product looks very impressive both in appearance and functionality. I had been using that over the last two days and it is simply superb. Thanks for accommodating some of my suggestions. On the use of earphones, the externally amplified sound doesn’t get cut off when … Continue reading “Dr. Suresh Ramachandran, New Zealand”

Dr. Suresh Ramachandran, New Zealand

“The Digital Metronome is a really outstanding product in every aspect. I tried it out and liked it very much. Its elegant light-weight design, sophisticated useful features, user friendly operation, perfect visual display, clear lucid manual and the professional packing, everything is just excellent. It will be very useful to everyone in the music field, … Continue reading “Mrs Meera Raghu – Carnatic Instrumentalist (Veena). New Zealand”

Mrs Meera Raghu – Carnatic Instrumentalist (Veena). New Zealand

“Hi Nagendra Thanks for introducing such a wonderful metronome. I will forward it to all the teachers and senior students associated with the Academy. We will also put it on our web site.”

Dr. Yogini Ratnasabapathy, New Zealand

“Dear Nagendra Your DGTAL- incredible invention!! I have bought two Talometers in the past and was a waste of money. This is so different!!! From the sleek look to the accurate time keeping -simply fantastic! It’s truly an amazing work! So easy to figure out the thalam. Liked the way you have worked out the … Continue reading “Dr. Jayasingham Jayamohan, Australia”

Dr. Jayasingham Jayamohan, Australia

“Dear Mr. Nagendra, We understand, you are through with your pilot production of the DGTAL. Congratulations!!! Wishing you Good Luck, God Bless.”

Dr. Bhagya Murthy, Singapore

“Vanakkam First of all I would like to thank you for the Digital that you so graciously gifted us. we had been using it regularly for our classes.”

Bombay Jayashree

“Dear Mr Nagendra, I compliment you on your initiative and I’m sure it’ll be welcome by many students and gurus. Incidentally, as you may have heard, I designed Taal Acharya, a first of its kind visual metronome and instructive software with 2 others in USA which was launched a few years ago in the Cleveland … Continue reading “Chitravina N Ravikiran”

Chitravina N Ravikiran