SMT HH with Micro Control

[FatBob]

I have a couple of SMT HH boards hanging around so I decided to make one an experimental
platform for some PIC development.

I picked up a 12LF1822 but then decided the VCC = 3.6V max would be a problem so I have some 12F1822's on order.

This is a 8 pin PIC with the Enhanced instruction set and it can run at 32mhz via it's internal oscillator.

I'll use one for the timing and then look for one to make the sounds (it might be a bit bigger).

So here's some pictures;

Board with docs


Board with parts removed (2 stage input mod done)


Schematic of new parts


Layout with notes


I'm sort of piggybacking off the old HH2 stuff but hope to go a little further.
I have a prog switch so could do 2 or 3 different programs.

[FatBob]

Here's some simple Basic code to get it running. Later we can get fancy and do some interesting things with the pulses.

FatHead1.txt

And here's an idea for Ground Balancing this thing;

[6666]

Good work, just for interest a few of us have the 12f1840 pic left over from the Pickini project, and it looks like you have included something like Tepco's gain GB system, been working on something similar.

[FatBob]

Here's a code update with the GB code. It may need some tweaks...

[6666]

Here's a code update with the GB code. It may need some tweaks...

Thanks , it would be helpful to know exactly which software you are useing to write the code and compile it. Looks a little like GCB.
Can it be ported to a 12f1840 ?

[FatBob]

I am using Great Cow Basic. The 12F1840 is the same as 12F1822 just with more memory
so just change the processor number define at the beginning of the file and it should compile
fine!

Great Cow Basic is a great program, it makes it easy to program these PICs!

[6666]

There does not seem to be a way of converting or compiling an asm file in gcb, I took your txt file and gave it a .asm extension and imported into GCB, but it does not like it, maybe we need your .GCB file ?

[FatBob]

FatHead1.zip
Here's the GCB file^

Just change the extension to GCB. I usually write in notepad then paste it into Synwrite (the text program that came with Great Cow Basic).

If you load GCB with all the bells and whistles it sets most everything up for you...

GCB takes a text file and parses it into assembly for MASM to use to make the HEX file.

[6666]

Thanks for the .gcb file that works

[FatBob]

So with the Ground balance added in we get positive responses to lower TC signals and
negative responses to larger TC's with a hole where the ground TC occurs.

To hear those signals we need a dual tone or dual VCO. Here's an attempt at a dual VCO;



Here's a Dual Tone one;



This might be easier to do on a full size HammerHead so I'll use this one for now;

[FatBob]

So I had bought some different size chips as I didn't know how many pins I would need and I just noticed the
8 pin and 14 pin have 8 pins in common. So you could install a 14 pin socket and plug in an 8 pin chip or a 14 pin chip.



The 14 allows for more inputs like this;

[FatBob]

So I'm going with something like this;



This allows for turning GB on and off, setting 1Khx or 3Khz transmit, up to 4 different programs
plus an alternating one similar to the MineLab stuff, and a couple of LED's for indicating the mode
we are in.

I found out the FET driver I was going to use shuts off at 11v - 13.5v as it is meant for a 15V - 30V
power supply so I changed over to a fast bipolar design.

Here's the piggyback board that sits on the original 221 and 555 sockets and make connection to
key signals;



My 5V PIC's came in today so we could get something running this weekend!

[6666]

I wish you luck, will be watching .

[mickstv]

Hi FatBob,

The pic below is what I use for my GB PI, it has threshold control and high/low variable pitch depending on target TC. Free to use or modify, if it's any help.

[FatBob]

Thanks for the circuit. I'll have to study it a bit to see what's going on...