Category: Pedal board
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Re-thinking the PU-2 interface: long live the MP-1
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,…
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VC-1: More impedance control
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…
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VC-1: Digital/Midi Volume Control
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…
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PU-2: SD card capacity
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…
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SD Card reader: No Voltage required!
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…
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PU-2: Data on SD card
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…
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FCB1010 vs PU-2: Why do it?
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…
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PU-2: Last delay
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…
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PU-2: A batch of Beta
I’m getting comfortable making the PCBs for the PU-2. This is what a batch of 5 boards looks like, fresh out of the etching tank. I still have to drill the 800-plus holes and solder everything… patience… This is what 10 Arduino Mega boards look like: The main components for the Beta. I now use…
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PU-2: Meet Beta!
The PU-2 made it to Beta. As you can see in the picture above, the PU-2 is an external module, linked to a connecting board inside the Behringer FCB1010 with a flat cable. The reason for the external module is that I wanted Beta testers to feel totally safe about their FCB1010. Since the current…