FV-1 Multi effect full forum project ready to go. (ShimmerVerb Also)

[Ice-9]

Right, let's get this going again for the weekend  

Mick - where did you get your boards fabbed ? Really nice quality.

All - Anyone know what kit I need in order to program the EPROM in-situ ? Off board ?  
I've seen discussion of the PICKIT2 product, but there seem to be a variety of options.  USB preferably - I've disabled the COM port on my motherboard.

I use PCBcart for board fab, they are the cheapest I have found  and have always been great quality. (need to get a reasonable amount to keep price low though)

Programming on board is easy with a USB PICkit2 (not PIckit3). there are 3 pads next to the Eeprom on the PCB which are gnd- data and clock. These connect to the pickit 2 the pedal must be powered to program it. If your PC is quite old and has a serial/com port then a programmer can be made for a few pounds.

I will post a picture tomorrow of board connections for power, battery and program port.  

[scuzzphut]

link for Pickit2 - will take a while to arrive from China - but I'll keep myself busy 

http://www.aliexpress.com/item/PICKIT2-Programmer-PIC-ICD2-PICKit-2-PICKIT-3-Programming-Adapter-Universal-Programmer-Seat-FZ0508-Free-Shipping/907663951.html

[bean]

Looks great so far! I finally have a reason to plug in my Pickit2. 

[scuzzphut]

Mick - I'm a wee bit confused as to the power connections and the orientation of the power MOSFET.

Here's how I think it's done - can you confirm ?

Thanks !
(PS Board almost populated )

[Ice-9]

PSU and battery  connections





The reverse polarity protection can be made up in 3 different ways if anyone prefers the diode type of reverse polarity protection.

1. Full mosfet low voltage drop protection (using the IRDF9024)
2. Standard diode to ground.
3. Diode in series.

I will post the pictures of all three ways as soon as I can.

[peterv999]

PICKIT, programming the FV-1 instructions are in my http://www.echotapper.nl/images/doc/eTap2hw.pdfb
could be applicable for this beautiful design also

Piet

[Govmnt_Lacky]

@Mick

A couple questions if you would indulge....

- The pot that controls the PIC to select the different modes. Is that a pot with detents? Could you possibly link to a good example?
- Will you still be posting a video about the programming of the 24-series EPROM? I have done it in the past with my PicKit2 and an adapter board (Thanks again Ian!) but it wont hurt to get a refresher.
- Board availability. Are there any? Could I get one with JUST the PIC soldered on? Costs?? I already have an FV-1, EPROM, and crystal. Need the PIC 

Cheers!! 

[Ice-9]

@Mick

A couple questions if you would indulge....

- The pot that controls the PIC to select the different modes. Is that a pot with detents? Could you possibly link to a good example?
- Will you still be posting a video about the programming of the 24-series EPROM? I have done it in the past with my PicKit2 and an adapter board (Thanks again Ian!) but it wont hurt to get a refresher.
- Board availability. Are there any? Could I get one with JUST the PIC soldered on? Costs?? I already have an FV-1, EPROM, and crystal. Need the PIC 

Cheers!! 

The pot that controls the PIC - I tried to track down a pot with 8 detents but was unable to do so, so at the moment the pot is a standard pot, I have been doing some searching and Piet has also been searching for a suitable 8 way switch. I think I have found a solution for this, as I designed the pcb with some solder pads which are under the PIC these can be used with a suitable switch instead of PIC chip.(its just that a small switch is needed because of the 1590b enclosure).

Programming the "24LC32 - Yeah I will be getting some info together, as Piet mentions above though, all the info on programming the 24Eeprom will be the same as at his echotapper web site. I will make a diagram with the Pickit2 to PCB connections and hopefully a little refresher on flashing.

I have been asked for boards and after doing some working out and adjustments to prices  have finally got to the correct pricing. See PM for pricing, It might be against the forum rules to post that here.

[Ice-9]

Connecting a pickit2 programmer to the PCB for uploading effects firmaware.



The pedal should be powered up to program the Eeprom, use a little 3 pin header wired to the Pickit2 and held onto the pcb pads to program.

[therealfindo]

Hi Mick,

so, ust looking at the board ,I see they're stereo jacks .. Is it a stereo circuit then?

[Ice-9]

Hi Mick,

so, ust looking at the board ,I see they're stereo jacks .. Is it a stereo circuit then?

No it's mono input/output. The Stereo jack socket on the input takes care of battery switching when a guitar lead is plugged in as in most battery operated pedals and the stereo jack socket on the output is because it means I  only need to order one type of jack socket instead of two types.
A mono jack socket can be used for the output jack socket if you have one, it makes no difference.

[Ice-9]

Looks great so far! I finally have a reason to plug in my Pickit2. 

Yeah, definitely dig out that Pickit2 Brian, it would be nice to see you join in on the fun.

[peterv999]

PICKIT, programming the FV-1 instructions are in my http://www.echotapper.nl/images/doc/eTap2hw.pdfb
could be applicable for this beautiful design also

Piet

http://www.echotapper.nl/images/doc/eTap2hw.pdf

Make sure voltage for programming is set correctly.
-Piet

[scuzzphut]

SO, I got this working tonight - and it sounds fantastic.

Mick had preloaded the EPROM with some of the community effects and I'm pleasantly surprised at what this chip can do.
In particular - Really good quality reverb  

For anyone building, I spent an hour tracking down why the output was drowned out by an almighty hum.

Turns out the pad highlighted below is not connected to the earth plane on the board - of course, that's the one I used for my off-board jack sockets. Sods law and all that.

My programmer is en route from China and I can't wait to start writing my own routines.

Thanks Mick    





Edit - also, in case it's not obvious - R22 is the LED CLR.

[Ice-9]

SO, I got this working tonight - and it sounds fantastic.

Mick had preloaded the EPROM with some of the community effects and I'm pleasantly surprised at what this chip can do.
In particular - Really good quality reverb  

For anyone building, I spent an hour tracking down why the output was drowned out by an almighty hum.

Turns out the pad highlighted below is not connected to the earth plane on the board - of course, that's the one I used for my off-board jack sockets. Sods law and all that.

My programmer is en route from China and I can't wait to start writing my own routines.



Thanks Mick    





Edit - also, in case it's not obvious - R22 is the LED CLR.

I'm glad you liking the your build of the pedal, the two Reverbs are a Room and Hall reverb which are from the Spin web site code which I modified a little. I have settled on a bunch of 8 effects to preload now which are all from what is freely available but have all been modified one way or another in little ways. I will post a list of what they are and see if I can put the .hex file up as well as an attachment.

The jack socket pin you have marked in green is not connected to ground as this jack is used as the battery switch so that when the guitar lead is unplugged it disconnects the battery. If that pin was connected to ground then even when the  pedal had no cables connected the battery would still power the circuit and just run flat.

Yeah R22 is the LED resistor and should be selected to suit whatever colour and brightness you like for the LED.

[scuzzphut]

I'm glad you liking the your build of the pedal, the two Reverbs are a Room and Hall reverb which are from the Spin web site code which I modified a little. I have settled on a bunch of 8 effects to preload now which are all from what is freely available but have all been modified one way or another in little ways. I will post a list of what they are and see if I can put the .hex file up as well as an attachment.

I didn't realise you had modified those presets, Mick - nice job. The one that uses the three knobs for straight/octave up/octave down was a nice surprise once I'd figured out what the hell was going on    Also the patch with delay and reverb is killer 

The jack socket pin you have marked in green is not connected to ground as this jack is used as the battery switch so that when the guitar lead is unplugged it disconnects the battery. If that pin was connected to ground then even when the  pedal had no cables connected the battery would still power the circuit and just run flat.

Got it.  I only had offboard jack sockets and couldn't wait to box up 

[peterv999]

Although the effort is now towards a BCD through a diode matrix replacing possible the potentiometer due to its delicate handling under performances on stage.
I have investigated this present 'Slacker' approach and measured the configuration. It seems that a simple resistor ladder-network is all that's required obviously with a 1P8T rotary switch.

The actual bandwidth between each selection is 0.4 volts. The nominal setting for the first position is on the 0.2 volts and the last position 3.0 volts (also a delta of 0.2 volts to the 3.2 supply voltage). The remaining 7 steps  are  the mentioned 0.4 volt.

Assuming that around 20 KOhm is an acceptabel value of the complete network this would calculate down to two 2K7 resistors in parallel for the first selection then  followed by 7 2K7 resistors for the next 7 selections and finally another two 2K7 resistors in parallel connected to the 3.2 volts This also makes the tolerance build-up  to stay fully within a working range.

[Ice-9]

Although the effort is now towards a BCD through a diode matrix replacing possible the potentiometer due to its delicate handling under performances on stage.
I have investigated this present 'Slacker' approach and measured the configuration. It seems that a simple resistor ladder-network is all that's required obviously with a 1P8T rotary switch.

The actual bandwidth between each selection is 0.4 volts. The nominal setting for the first position is on the 0.2 volts and the last position 3.0 volts (also a delta of 0.2 volts to the 3.2 supply voltage). The remaining 7 steps  are  the mentioned 0.4 volt.

Assuming that around 20 KOhm is an acceptabel value of the complete network this would calculate down to two 2K7 resistors in parallel for the first selection then  followed by 7 2K7 resistors for the next 7 selections and finally another two 2K7 resistors in parallel connected to the 3.2 volts This also makes the tolerance build-up  to stay fully within a working range.

Thanks for this extra information Piet, that's great. The switches I have been waiting on have arrived today and I am about to start making up a couple of different ways to use the switch. As you say I was going to start with the 1p8w with diodes first which would mean the PIC could be left off the pcb altogether.
I will try out the resistor ladder that you have outlined above as this will have fewer components along with other advantages of being an easy replacement for the pot.

[scuzzphut]

Brilliant stuff, Piet.

On switches - I've found these from China (UK ebay, but I'm sure they're available all over) ---> http://www.ebay.co.uk/itm/1-Pole-8-Position-PANEL-PCB-Wiring-ROTARY-SWITCH-1P8T-q-/180699868121?pt=LH_DefaultDomain_0&hash=item2a128d2bd9

Also found this one from the Spin forums - it's binary coded  - >
http://uk.rs-online.com/web/p/rotary-switches/6553235/?searchTerm=655+3235&relevancy-data=636F3D3126696E3D4931384E525353746F636B4E756D6265724D504E266C753D656E266D6D3D6D61746368616C6C26706D3D5E5C647B337D5B5C732D2F255C2E2C5D5C647B332C347D2426706F3D313426736E3D592673743D52535F53544F434B5F4E554D424552267573743D36353520333233352677633D4E4F4E4526#header

[Ice-9]

The switches I received today are these ones http://www.musikding.de/Print-rotary-switch-1P8T I have just breadboarded Piet's resistor ladder and it works great. These switches are cheap enough but more importantly are small enough to replace a 16mm pot in a small enclosure and they feel good quality too.

I will be making up a small PCB for the switch and resistors but this could easily be knocked up on a piece of vero board with SMD resistors just soldered across the tracks. Then its just a case of replacing the pot with the switch (same 3 wire pads on the PCB).

Great work Piet.