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tecnical decription of the PEDAL


- page last update october 2009 - (página en castellano)

The entire project, including all electronic schematics, the C and the HEX source code for the PIC 16F690 microcontroler, as well as all electronic schematics of the circuits and the program written with PD (pure data) can be downloaded as a ZIP file at the bottom of the page.


wireless Pedal for OSC or MIDI messages using Pure Data.

The pedal is thought as a compliment to the wireless panel (see project) and permits to assign pad functions to the pedal. If one has to adjust the volume of an application using a pedal is much more useful than to hit several times a pad by hand or a stick.
But the wireless pedal can be used without any problems as stand allow n application together with a little patch written in Pure Data. (can be downloaded at the button of the page).
The program for for the 16F690 is written in C using Source Boost with PIKLAB (Linux).
To avoid problems with other received data the PIC send for each capture a three byte package: First start-byte ( (0x7d), second the data read with the analog input and third a stop-byte. The simple program in PD filters the start- and stop-byte and lets only the captured values of the potentiometer through for further use.

This simple project involves only two small PC-B's and a patch written in Pure Data.

1. a circuit called “Pedal” using a PIC16F690 and a xBee module.
2. a receiver circuit with an other xBee module and a FT232 IC.


Pedal schematics
esquema Pad_trigger_HC14



This is a small circuit receives the incoming data with a xBee module and transforms the data flow with UART to USB converter using a FT232
An other option to build an interface to the computer is presented in the wireless panel project (see project) and uses a MAX232 level shifter to do the job.
Both circuits works without any modification with the program attached at the download file for Pure Data.

esquema Pad_18442_xBee

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