Practical Usage

Category: Arduino

  • Re-thinking the PU-2 interface: long live the MP-1

    —

    by

    rt
    in , ,

    A lot of work was done on the PU-2 over the last many months by Emanuele and I. More specifically, we wrote hundreds of line of code to make the FCB1010 work with Banks of Stompbox mode midi commands. This is the main feature of the next version of the firmware. At the same time,…

  • EM-1: Energy Monitor – Completed Hardware

    —

    by

    rt
    in ,

    Christmas vacations are for having fun. I did have fun! I completed a project that had been sitting idle for some time: The Energy Monitor for the house/office. The project is described over a few other posts. Most of the theory and practical application is explained in detail at openenergymonitor.org. I adapted their circuits for…

  • VC-1: Volume Control Beta

    —

    by

    rt
    in , , ,

    The VC-1 is. On the left, the Silonex Audiohm opto-couplers (OC) with the electronic drivers. it has been described here. On the right, the line-buffer/impedance-controller described there. It works as expected, using two digital pins on the Arduino micro-controller to change the volume. Partial specifications I use 2.2 Mohm metal film resitors as a voltage…

  • VC-1: More impedance control

    —

    by

    rt
    in , , ,

    In the previous post, I described the circuit that I’m using to emulate a potentiometer using a couple of opto-isolator (or opto-couplers?). There is one small problem with the circuit: the input impedance has to be quite low. If you just plug a guitar in the circuit, which generally has a high impedance output, it…

  • VC-1: Digital/Midi Volume Control

    —

    by

    rt
    in , , , ,

    A user asked if I could design an FCB1010/PU-2 volume control. I love challenges… It took me weeks to get one working properly. The are two main parts to this: the analog side and the digital side. The analog side A potentiometer will generally be connected between ground and signal as: In this case, the…

  • PU-2: SD card capacity

    —

    by

    rt
    in , , ,

    I have just written a new version of the software that is used to convert a .CSV file into a Sysex file that the PU-2 can process. This version uses the SD card. Preleminary tests show that 2000 midi commands require about 16KB of storage. So, my (very) old 16Meg SD card can store approximately…

  • SD Card reader: No Voltage required!

    —

    by

    rt
    in , , ,

    While testing a slight modification on the PU-2 prototype, I decided to test the current draw of the SD Card reader described in the previous post. I placed my multimeter in series with the 3.3 volt pin and measured 11 milli-Ampères. Even while reading data, the current draw was constant. I then decided to measure…

  • PU-2: Data on SD card

    —

    by

    rt
    in , , ,

    Just in time! I received the SD card readers the day that I had planned to ship the first PU-2 Beta. I re-opened the boxes and fitted the card reader in each prototype. This is the SD card reader that I chose: It’s a generic card holder, that has the advantage of working with both…

  • FCB1010 vs PU-2: Why do it?

    —

    by

    rt
    in , , ,

    While waiting for parts (I do have to get a better inventory “system”) to complete the Betas for the PU-2, I went through a short period of discouragement. It’s hard to stay fully motivated when the project is bogged down by unforeseeable delays (or is it bad management?). But yesterday, I read an entry on…

  • PU-2: Last delay

    —

    by

    rt
    in , ,

    As I’m completing assembly of the first of five prototypes, I decided to test the unit before putting it all into a box. Since I want the PU-2 to include a USB-Midi interface, I use the technology that I documented here. I ordered a few more Midi interfaces from a local (North-American) EBay supplier. The…