Monday, December 19, 2011

iChromatic Strobe Tuner now in the Mac App Store

I was surprised when I looked in the Mac App Store a few weeks ago, and didn't see any musical instrument tuner applications that were, in my opinion, both attractive and accurate.  So I created a new chromatic strobe tuner app just for the Mac.  The HotPaw iChromatic Strobe Tuner is now available from the Mac App Store for an introductory and fairly low price.

The visual concept is very similar that used in my popular inTuna Guitar Tuners and iChromatic HD Tuners available from the iOS App store.  However, I used the greater processing power available on the Mac to display more attractive circular pitch strobes (two of them), plus a note-on-keyboard indicator and a music grand staff display, as well as usual meter dials and frequency read-out.  It supports a configurable Concert A frequency and several settings to customize tuning intonation by cents.  Check it out, and feel free to send feedback (or bug reports if you find any).

Thursday, December 1, 2011

HotPaw Morse Decoder, now available for the Mac

The HotPaw Morse Decoder app for the iPhone and iPad has turned out to be a surprisingly popular app worldwide, selling copies in almost 50 countries, and getting great reviews.  (Although it never hurts to have more! :)

The Morse Decoder has now been ported to Mac OS X.  Version 1.0 of the HotPaw CW Morse Decoder for the Mac is available from the Mac App Store.  The features are nearly identical to the iPad version of the app, including the narrow band audio filtering and high speed QRQ mode with can decode Morse Code at over 80 WPM in good conditions.

So, the interesting question will be: How many radio amateurs use recent Macs?

UnTouchType for iPad

Version 1.0.0 of UnTouchType is now available as a Free app from the U.S. iOS App Store.  Experiment with chorded one-hand touch text input.  The app can speak each letter on input for audible verification.  But the current version is very plain, and only allows one short line of text input.

I am awaiting a bit more user feedback before updating UnTouchType with a version that will allow the user to customize their preferred keying combinations by uploading a text file using iTunes.

Monday, July 18, 2011


I usually don't announce apps in development until they are ready to ship, approved by Apple, and available in the App store. But I recently demonstrated an early version of an app, on stage, at the close of the iOSDevCamp 2011 weekend Hackathon. So I might as well write about the idea behind an app still very much under construction.

Since adding support for Apple's VoiceOver Accessibility to a few of my apps, I've received enough customer feedback to realize that that iPhones and iPads are more popular among blind (or otherwise vision impaired) users than I might otherwise have suspected. By user request, I even developed an app specifically for this market segment, the HotPaw Talking Tuner.

Now, to segue into a bit of computer history: On December 9, 1968, Douglas Englebart, in what has been called the "Mother of All Demos", demonstrated on stage several innovations including the computer mouse, hypertext linking, online collaboration, and some precursors to bitmapped graphical user interfaces. He also demonstrated something less well known, the chord keyboard. This was a one-handed keyboard that could be used to enter text by hitting a combination of buttons. Chord keyboards haven't become popular because it takes some time to learn the key combinations. But if a person needs to enter text with one hand, and takes the time to learn the chords, it is a fairly fast input method.

One current problem with iPad text entry is the lack of tactile feedback when tapping on keyboard icons and other GUI buttons. This makes it difficult to enter text "eyes-free", that is, without looking at the display. Apple's VoiceOver Accessibility technology provides one solution, by giving synthesized voice feedback about where the graphical keys are located. But it currently seems difficult to make VoiceOver work for chorded multitouch input positioning.

My prototype solution is to have an app dynamically place 5 keyboard buttons wherever a person places all five fingers on the display, then record actions, not by tapping on buttons, but by lifting fingers up off the multitouch display. These finger actions can be converted in a "chording" input method by using the combination of which fingers one picks up to select a character for input. Combinations of lifting touches and swiping gestures can be used expand the potential vocabulary. Since this method is actuated, not by touching, but by lifting fingers up, I am calling this input method:


In a day or so of coding at the Hackathon, I got the an app working well enough to demonstrate to a few people; and they thought it was an interesting enough idea for me to demo. Unfortunately, it didn't work for me on stage at the conclusion of the iOSDevCamp Hackathon. (Playing with the app and accidentally turning on the mute switch just before my presentation slot didn't help. Live and learn.)

If the kernel of this idea is a new innovation, consider it to now be in the public domain. Some experimental works remains on how fast this input method is compared to other eyes-free input methods on touchpads, and which finger/chord/letter combinations might be faster and/or easier to learn. Stay tuned.

Dance Metronome/BPM

This month, HotPaw Productions introduced a new iOS app, Dance Metronome/BPM now available from Apple's iTunes App Store. This app has both a tap BPM (beats per minute) meter and a very accurate metronome. The BPM meter is designed for ballroom dancers, as it indicates whether a particular tempo is within strict tempo range. All the International Standard, Latin and American Style Smooth and Rhythm dance tempos are included. The metronome in the app can play beats, on time, to sub-millisecond accuracy. (Given an audio sample rate of 44100Hz, there are 44 samples per millisecond, and the Dance Metronome/BPM app calculates the nearest exact sample to start playing each on-time beat.)

Friday, June 3, 2011

June App Updates

The Morse Decoder app for iPhone and iPad has been upgraded to version 1.7. It now includes a new High Speed WPM mode switch to support decoding really fast QRQ WPM speeds from 40 to 80 WPM. Morse code just sounds like a blur at those rates. The HotPaw Basic app includes a "morse" command which supports sending Morse Code sounds up to 99 WPM.

The HotPaw Music Spectrograph update to version 1.1.2 will now allow you to analyze music from your iTunes Library. Hit the "Song" button, and it will let you select a tune to convert and visualize in spectrograph form. You can stop and replay sections of music to (re)hear what interesting looking segments of the spectrum graph sound like. I used it to help transcribe some complicated fast piano riffs. Currently does monophonic analysis only.

Sing-inTuna update version 2.1.3 includes a fix for a rare problem where someone reported the app needed to be force quit and restarted to get audio working again.

Friday, May 27, 2011

May App Updates and News

The HotPaw Sing-inTuna app has been updated to version 2.1.2, with improved audio processing and graphics performance. This should help reduce the random low frequency dots that occasionally appear in the voice pitch graph.

The MorseTest app has been updated to version 1.1.6, with support for a couple new Morse Code punctuation characters added. VoiceOver support should also be improved in this update.

Blind Talking Tuner has been update to version 1.0.1, with an easier to understand speech synthesizer voice.

Austin Seraphin wrote a nice blog post reviewing the HotPaw Morse2Text Morse code text entry app.

Tuesday, April 26, 2011

YouTube video showing the HotPaw Morse Decoder

Here are 2 YouTube video's I found which show the HotPaw Morse Decoder in operation:

Morse with iPod Touch


Morse Code Decoder iPhone App

They both show the built-in spectrum analyzer. Pretty cool.

App Updates

On 4/20, the HotPaw Music Spectrograph was approved for App store distribution. Music Spectrograph is a great way to visualize live music and sound. It uses a scrolling piano roll display similar to some midi composition tools. It took Apple 7 days to approve Music Spectrograph.

On 4/11, the HotPaw Morse Decoder was updated to version 1.6.2, with a new low pass filter and better WPM estimation logic. It took Apple 2 days to review this update after it was submitted.

On 3/30, the HotPaw inTuna Strobe Guitar Tuner was updated to version 3.0.2, with fixes for a potential app freeze up. It took Apple 4 days to review this update.

On 3/23, HotPaw Basic for iOS was updated to version 1.5.3, with some fixes to matrix multiplication. It took Apple 7 days to review this update.

On 2/25, the HotPaw Blind Talking Tuner was released to the iTunes App Store. It took Apple 9 days to review this new app.

On 2/22, the HotPaw inTuna Strobe Guitar Tuner HD (for iPad) was updated to version 1.2.1, with fixes for audio recording occasionally cutting out. It took Apple 2 days to approve this update.

On 2011-Feb-08, iChromatic HD (strobe tuner for iPad) was updated to version 1.0.2, with added support for A=415Hz tuning for historic/vintage instruments. It took Apple 4 days to approve this update.

HotPaw Productions announced Music Spectrograph for iOS

Santa Clara, CA - HotPaw Productions announces Music Spectrograph 1.0, now available from Apple's iTunes App store. Visualize sound as musical notes on a piano roll. See mic input graphed in real-time, almost as it might appear in a MIDI music editor, to assist with music transcription. Find notes hidden inside chords, or just watch the rise and fall in the pitch and all the overtones of the sounds around you. The Music Spectrograph uses real-time signal processing to create a scrolling 12th-octave spectrogram, with each frequency band centered on a musical note.

The Music Spectrograph app might prove helpful for for music education, music transcription, acoustics understanding, speech therapy or vocal training.

Mrs. Nicholson says: "Wow, that's a really cool looking app. What's it do?". The developer's cats just looked at the app and went back to napping (as it obviously wasn't a mouse or a bird).

Ron Nicholson founded HotPaw Productions in 1999, first developing mobile apps for PalmOS devices, and has been developing iOS apps since the App store first opened. There are over 20 iPhone and iPad apps developed by HotPaw Productions the iOS App store, including the inTuna Strobe Guitar Tuner, Sing-inTuna, and HotPaw Basic. Copyright (C) 2011 HotPaw Productions. All Rights Reserved. Apple, iTunes, iPhone and iPad are registered trademarks of Apple Inc. in the U.S. and/or other countries.


Ron Nicholson

HotPaw Website Updated

The HotPaw website has been completely updated, with new css, and a new 3-column look. Many thanks to lizdesign for the web site design and many of the icons, including:

Music Spectrum icon