Category Archives: PIC Microcontrollers

PIC based circuits.

Nintendo DrumAxe Controller

Tony of Electrokraft has just released a set of new products: Super Synth Drums the DrumAxe. Both work in conjunction with an NES system running custom software called Super Synth Drums. The software translates button presses into Drum sounds that are being synthesized by the NES itself. Everything was written in 6502 assembly language and burned to a ROM by Tony. His main resources for learning ASM were books like “Atari Roots” by Mark Andrews and others written in the early 1980’s, as well as help from people at the website.
In the heart of the circuit is a PIC microcontroller driving a 4021 “parallel to serial” shift register. Multiple input buttons or in this case touch sensors are encoded to single serial output that is understood by the Nintendo System. The Sonic DrumAxe essentially replaces gamepad #1 on the NES. The second gamepad can be used to add a variety of pulsing/looping effects. Unfortunately given the current legacy status of the NES hardware, the actual NES connectors are hard to come by without cannibalizing and existing system, so Tony devised an RCA style setup with an OEM DIN to RCA cable. 4 RCA jacks on the NES correspond to the Clock, Latch, DATA, and Ground required for sending bytes to the NES CPU.

There will be an upcoming tutorial demonstrating how the Sonic Drum Axe’s circuit was made and how it’s connected to the NES. Also for those who have already purchased the Super Synth Cart or are thinking about it, please keep in mind that in the future Electrokraft may offer free ROM upgrades, which will include more sounds and features! Harmony Central just did a wrote up as well.


Super Synth Cart and the Drum controller are for sale at or on eBay, part of the proceeds will be donated to humanitarian organizations. Thanks Tony, great work!

New HighlyLiquid MIDI kit for Atari 2600

Circuit Bent Atari 2600 MIDI Kit

HighlyLiquid has created another wonderful MIDI kit for emulating joystick control of an Atari 2600 with MIDI signals. Directions and buttons are mapped to a specific MIDI Note along with different keypad values. The the left and right ports can be independently configured via a dip switch to be either a Keypad or a Joystick. This finally allows the sweet sounds of Synthcart to be sequenced via computer. I can also picture using this kit with circuit bent devices that have an Atari Joystick style (DB-9) connector for triggering bends as well as custom circuits that rely on the same pin out for note triggering. Very nice work!Atari 2600 synthcart midi

MIDI Speak Kit demo on Hak.5

hak5 midi speak episode

Highly Liquid’s MIDI Speak kit got a shout out on the Hak.5’s ubergeeky show Episode 3. A Canadian musician/engineer Andrew Barrow demonstrated the Nintendo Power glove being hooked up to PIC controller that converts its 3D movements into a MIDI note stream. The result was a stream of speaky-gargali-gook. In the segment Andrew does a good job of describing the ease of the MIDISpeak Kit installation process and the general terminology of what is happening and why. The Speak and Spell segment starts at about 47 minutes. Enjoy. Via the New Highly_Liquid Blog.

Ghetto Drum System

Ghetto Drum CaseGhetto Drum Pic circuitGhetto Drum Pic Controller

This acoustic piezzo trigger to serial interface is indeed pretty ghetto, but never to less there is plenty of great information on about programming a Pic Microcontroller for building such a device.The creator decided to use strait serial protocol for triggering samples through a custom application running on a PC and not through standard MIDI. Also housing projects in an external drive case does have advantages. Its cheap, rugged, and has a nice power supply built-in, so the circuit does not have to rely on battery power. The cases can always be painted if needed.

Musical Blackboard for Casio MT-240

A Kaoss pad like device entitled Musical Blackboard was built by Ryan Avery and can be seen in action with this very educational video. The metal sheet interface is used as a sensor for reading body capacitance based on the hand position. The readings are done utilizing a circuit published by the delayed John Simonton of PAIA. Pic microcontroller is then used for processing the values and converting them a stream of serial data that triggers a 40 pin parallel switch circuit. The result is a burst of bends being articulated by the hand movements on the surface of this board. Pure circuit bent/pic microcontroller goodness! More images and the project page is located here. Enjoy.

Prophet 64 MIDI interface Prototype

So far this interface does not look like much except for a large PIC protoboard with some serial and midi connections. However the sounds are very impressive, listen to sample 1 and sample 2. firestARTer has been hard at work on The Prophet 64 Cart interface promising to deliver full MIDI parameter knob tweakage and notes for complete SID control. The previous version of the Prophet 1.0 interface can be researched here which is a DIN-SYNC with MIDI start and stop. The Prophet64 group has been fairly active covering the new Prophet64 craze. People are going all out to mod their c64s with PSone LCD panels for ultimate portability. The manuals are still not done however older versions of the Free Prophet 64 can be downloaded from my local Mirror.

Pic Based Pitch sequencer for Toy Keyboard

Over the past few weeks I’ve been tinkering with PIC Microcontroller programming and hardware development ( ie: Stringing things together with clip leads DIY style ) .The result of the initial trials turned out quite nicely. Based on a simple premise of taking a toy with a pitch resistor and varying the value of that resistor sequentially. This creates note strings and also at higher tempo frequencies more modulated sounds. Unfortunatelyy PIC 16F627 does not have a DAC that would output specific voltages, but it does have plenty of PINs that can be turned OFF and ON, the easy way to create some cascading variations is to use something called a resistor network and in this case I took advantage of parallel resistor properties while keeping things isolated with a 4066 quad switch IC for building the resistor ladder. When all the switches are ON the resistance is least compared to when all of them are OFF. This coupled in parallel with a 1Meg Pot provides for some nice variations. The sequencer program running on the PIC has 16 steps and each resistor has its own channel of ONs and OFFs that can be “Muted” if needed. The controller has only4 buttons and 4 LEDs, however many buttons are overloaded with functions so different combinations do various things like speed up and slow down the tempo, randomize patterns, randomize step lengths to create “Swings”, and also edit patterns in a special mode. As a bonus MIDI out port sends out the 4 note patterns than be mapped to Samples, Drums, or Synth sounds. All that functionality really maxed out the massive 1K of Program space, granted the code is not the greatest and was written in PICClite, but the DSI keyboard turned out quite nicely and is lots of fun to play around with. There is also new blog which will have more tips and tricks of the MIDI and PIC programming located at, contributors will include myself and Electrokraft. A schematic of my circuit is posted as a general idea. Actual circuit is a little different, but if anyone has suggestions please let me know.
Video of the keyboard in action as well as some prototype photos are available.

Therepings in action

The latest issue of Nuts and Volts has featured an article on Therepings.
These devices are created with the use of Ultrasonic robot proximity sensors, buttons, and Basic Stamp Homework boards. The sensors read hand positions and then convert that to preset scales with heavy note quantization. Cheesy electronic drum beats being played live in the background can be seen and heard in these really bad videos: Video1, Video2. The description on the site states that Therepings can be played together to create interesting music without any musical experience on the part of the players…….Well, you be the judge….More info and source code available through the site. I guess the concept of a Thereping Jam band really seems like a very Geeky version of Karaoke to me, except not as fun. My suggestion would be to hook these up to samplers with animal sounds and then go to town.

Software Needed

Lets take a moment to talk about development tools. Three software pieces are needed to make a PIC IC do something. First we need an editor for writing the Code. These editors are called IDEs ( Integrated Development environments ). There is no reason why one can’t use Notepad or Vi for writing their code, however having an IDE is a lot better because things get color coded, errors in the code are easily spotted, and various tools for debugging and testing are also there. Some IDEs are quite pricey, but the one I chose to use is a very nice free one called SourceBoost IDE. The second piece is the compiler/linker this step takes the Code written in a language of choice like Basic, C, or Assembly and converts it to HEX format that the PIC can understand and execute. The compiler I used is PicC-Lite and it is available totally free from HI-TECH software. The 16F627 is supported by the compiler, however some other variations may not be. The final piece of software is the program transfer utility. The VM111 board comes with a ProgPic2.exe in the box and others are available. The software installation does not have to be done in a specific order but loading the VM111 kit software, then PICClite, and finally SourceBoost IDE should make things easier. Windows XP, 2000, and 98 will all work the same and a true Serial port needed for programming because USB to Serial will not work with this kit.

VM111 from QKits

The Kit arrived from QKits Company in Canada to Iowa, USA in 5 business days, just in time for the weekend tinkering. Order Satisfaction is definatelly a 10. Contrary to the online description, it did include a Serial programming cable, a nice bonus. There was also a mini CD which had the software, schematics, and manuals for all the Velleman Kits on it, double bonus! However finding the VM111 folder was a little hard at first. The printed manual is identical to the online PDF version, however it proved very valuable during the development process. The PIC was already inserted in the socket. There was no description of the power supply polarity that I could find. Outside minus(-) inside plus(+) is what the board takes. 9V 300MA ended up working out just fine.