Vacoloco Ramblings

I have the parts arriving for 10 more kits.

I’ll call these “kit 6″, and they will contain:

• 1 x PCB
• 1 x Micro (pre programmed)
• 12  x Switches
• 12  x Switch Caps
• 4 x 7 Segment Displays
• 1 x 16Mhz Oscillator
• 1 x 5V Regulator
• 8 x Potentiometers
• 1 x I2C EEPROM
• 2 x MIDI Sockets

Well, it’s a new year (for those who missed it, SURPRISE!!) and GorF is done, so what next?

Well, I’m going to be focusing on two projects this year, and only two. in no particular order;

Defender:-

It seems a shame to have that lovely panel sitting there dead, and a voice card that works doing nothing, so I’ve done a bit of re-engineering and redone the panel PCB. So, instead of having a panel PCB connecting to a master micro which has MIDI and controls the voices, I have included the MIDI on the panel PCB, a MEGA128 micro and an I2C EEPROM for patch storage. The board will handle 192 LEDs, 192 Switches and 32 analogue inputs. Here’s a picture of the PCB in Eagle, boards have been ordered;

The other project that I’m focusing on, is the QiX project. For those who don’t know what it is, it’s a hybrid CPU and DSP on a board. A bit like the Sound-Art Chameleon, but on Steroids. The CPU for the first one will be an i.MX233 ARM9 system on a chip (Freescale video on YouTube) and a dual core 56k DSP, a bit like the soundbite board from Freescale, but with external memory.

Well, I finally got around to recording and editing a GorF video guide. it’s in two parts as YouTube won’t allow me to upload more than 10 minutes of video.

So, without further ado;

Well, what would you know, I was tidying up my “parts bin” and found 10 more GorF PCBs, these are ones I took to Synth DIY UK 2009 and never sold (everyone bought full kits).

So, I’m considering doing a run of another 10 “hard to find parts” kits, so this would include:

• PCB
• Micro (pre programmed)
• Switches + Caps
• 7 Segment Displays
• 16Mhz Oscillator
• 5V Regulator
• Potentiometers
• I2C EEPROM
• MIDI Sockets

Well, it’s finally here.

I’ve managed to get some time this week and put in the last few touches. We now have support for 64 sequences, 8 banks, each with 8 sequences. You’ll need to have the I2C EEPROM to get banks 2 - 8 to work, and they’re a little bit slower when loading and saving, so you’ll get a bit of a hiccup using these, sorry nothing I can do about that.

On this note, loading and saving has changed slightly. Now you push the load button once and you can load a sequence from the current bank. Press the load button again and you can now select the bank. Pushing the load button again, will take you back to sequence selection. To get out of this, push the mode button.

The same is true for the save button, it’s a little different to previous, but it should be fairly intuitive.

To support the fact that you might load “random” sequences from the new EEPROM before you’ve saved anything valid, I’ve included a check for the data in a sequence as far as possible, so you shouldn’t get any steps that are 255 clocks long and a sequence length of 255 steps. If this does happen you’ll see “BAD DATA” on the display and it’ll change the values to some defaults (8 steps, 12 clocks per step length and so on).

There’s also now a “snap” mode for the knobs, so if you have a slightly unstable power supply this should help saving unplanned value jumps when moving around GorF. Pressing step button 1 when in control mode toggles it on/off. When enabled if you turn a knob and it’s above the value you’ll see “hi” if it’s lower you’ll see “lo”, then as you hit the current value, it’ll “snap” and start changing the value.

I’ve updated the GorF downloads page with the new sysex file, the files needed for AVR Studio and also the source code for version 1.00. I’ll be creating a video in a few days time and uploading it to my YouTube page running through each feature.

Unless there’s any major bugs I don’t plan to add any more features. GorF has already gone way beyond what I had originally intended and I have other projects I really want to get moving (like Defender) and now I have the perfect test tool for my bench.

I want to thank everyone who’s purchased a GorF kit I never thought they’d sell so well. I purchased 100 PCBs a year ago and I now only have 5 left. I am amazed at the positive response this project has had and flattered at all the words of support I’ve received, thank you to each and every one of you, you guys made GorF what it is.

Finally I got the blasted I2C EEPROM working…. turns out I had two faults;

1. I was missing the 10mS delay at the end of the write! Thanks to Peter Ullrich for spotting that.
2. I had made a mistake with the way I addressed the data, in a way that meant I could only write data to one patch in a bank, writing to the same bank would corrupt the other patches, what a muppet!

Well, I have say, it’s official, I hate I2C.

I’ve been battling on and off for a couple of weeks now, and I’m at my wits end. I can get it to write/read a single value to I2C EEPROM, but writing/reading more than one seems to cause corruption.

so, I’ve uploaded the current version of the code to the downloads page, if anyone can get it working I’d be truly grateful.

As promised, here’s pictures of a quick mod to help stabilise the 5V running around GorF (Click the images for a bigger version).

Take two 100nF caps, tin the legs, and cut them quite short, maybe 15mm.

Solder them to the regulator, as in the picture above. The middle pin is Ground, one is the input and the other is the output.

Pop the lid back on, and you’re ready to rock-n-roll again. The reason for doing this mod on top, even though it’s more awkward, is that it won’t affect the way the PCB sits in the case.

It’s been a while since I did an update, so….

Whilst away on holiday I managed to get the I2C link working for the EEPROM, I’ve added a bank selection mode and it’s almost working (reading and writing a single byte works perfectly, but writing a patch, then loading it seems to cause some mangling).

Hopefully in a week or so, there should be a version 0.31 of the OS up, which has working bank selection.

I’ve also tidied up the start up process, so when you power up GorF doesn’t mangle the patch loaded for the first run through. and tidied up the internal code a little bit.

Some people have had issues with noisy supplies, the simple fix for this is to take two 100nF capacitors, solder one across the input of the 7805 regulator, and the other across the output of the 7805 regulator. I’ll add this mod to mine, take pictures and upload them in the next couple of days so people can easily see good places to solder these.

In the meantime, I have 15 GorF PCBs left, I have 15 MEGA32’s to hand which I can program up as required. Just to give the prices again ;-

Kit 1 (7 UKP) , PCB only, postage is

• 1 UKP to the UK
• 2 UKP to Europe
• 3 UKP to the US
• 4 UKP to anywhere else in the world

Well, the last GorF kit 5 has been shipped. There now remains less than 20 PCBs to sell. I have enough micro’s left for the 20 remaining PCBs should people want “kit 2″.

I’m still trying to find time to work on the final bit of the code, support for the I2C EEPROM. I’ve been doing some digging and friend pointed me at a handy resource which should answer the questions I have.

I’ve got a couple of updates I need to add to the page, including pictures of various cases people have made and some other useful additions (like a PDF showing placements of parts, thanks Peter).