All Set? LET'S BUILD!
Here are the parts needed for assembling the pi-Stomp Core PCB
To save you from the often frustrating soldering of surface mount components, we've presoldered the voltage regulator for you. You're welcome!
Many of the headers are optional and provide interfaces for your own customization. Good idea to check out the Customization guide and consider how you plan to customize, so you can choose the ideal configuration.
Pay close attention to which side the header should be inserted - the side with the silkscreened name. Unsoldering a misplaced header is not fun
It's important for headers to sit tight and perpendicular to the board. I use tape to keep it in place until a pin (or two) is soldered, then adjust as necessary before soldering the remaining pins
This header is optional but recommended if you might need access to extra GPIO pins for Outputs (LED's, etc.) or direct (not ADC or debounced) inputs.
This header can be installed on either side of the board. The top side (with the silkscreen next to the encoder) is generally more accessible until mounted inside an enclosure. Angle the pins slightly upward (maybe 10 to 15 degrees) so that jumpers can be attached and clear the IC which will be installed South of it later.
OR…
…for connections after mounting in an enclosure, you may prefer the header to be on the bottom side (side with red capacitors).
The build depicted from this point onward has the HGPIO header mounted on the bottom side.
Depending on how you plan to enclose the pi-Stomp you might choose to use a different header or mount the LCD directly to the PCB.
If you want the LCD to be mounted underneath the top panel (requires a rectangular cutout - not trivial without a CNC or patience with a file), then you won't likely be able to use a plug-able header because that would place the top surface of the LCD above the pot and encoder. Soldering the LCD directly to the board, will result it the LCD face being just about where the pot and encoder go thru their enclosure holes. So in that case, skip installing this header and wait until the pot and encoder are mounted (last step), then solder the LCD directly to the board at a height that matches the pot and encoder. Some hot glue around the pins could increase mechanical stability.
If you want to be able to unplug/swap the LCD, then a header should be soldered instead of the display itself. The provided 1×9 female header should result in the display sitting on top of the enclosure top panel surface. Not quite as aesthetically pleasing, but it makes machining of the enclosure easier (only a narrow slot for the pins is required) and it allows for unplugging/swapping the LCD. The rest of the build instructions assumes this configuration.
These are the headers for the output and input jumpers. When complete they should look like this:
Note how the black plastic ends up perpendicular to the board not flush to it.
Use tape to secure each while soldering. It can help with positioning if you attach a jumper as it will be when eventually connected.
HOut header:
HIn header:
This provides the interface for attaching pushbuttons or footswitches which require debounce.
If you plan to mount pi-Stomp core into a very small enclosure (like a 1590BBS) and plan to have 3 footswitches, it has been done, but you'll likely find that some of the header pins will be obstructed by the middle footswitch. I was able to accommodate just the connections for the 3 footswitches by breaking the header down to a 2×3 and connecting only inputs 2, 3 and 4.
This is optional, but recommended unless it would interfere physically with external components. It exposes the UART of the Raspberry pi (pins 8 & 10) plus 3Volt power and ground. The most likely application is adding MIDI In and/or Out. Third party boards exist for this, or it's really easy to create your own. See pi-Stomp Customization guide for more info. Again, like the HSwitch header, if you plan to use a 1590BB enclosure with 3 footswitches, these header pins will likely be obscured. You could hard wire a ribbon cable to the board in that case.
This is optional but recommended unless you plan to repurpose it for direct SPI to your own hardware. It provides 8 analog inputs. See the Customization guide for how to use or repurpose as a direct SPI interface.
The sockets have a notch to indicate pin #1. Orient that to match the silkscreen notch.
S2 (the ADC socket) is recommended for most builds unless you plan to replace the ADC with your own hardware connected via SPI (see the Customization guide)
Make sure these are inserted from the correct board side. Unsoldering them is a bitch.
The last part is often the trickiest. The encoder Enc has very short pins, but for it to sit tight against the enclosure face, it needs to sit at roughly the same level as the Vol pot. It should rest on its side tabs at the appropriate level, however, it can rock and end up not perpendicular to the board. So…
The pins of the IC's usually need to be bent inward just a millimeter or two before inserting. Lightly squeeze all pins between thumb and first finger.
All IC's are polarized. Make sure the notch/dimple (indicating pin #1) ends up on the same end as the silkscreen (and sockets if you installed them right). Worse case, match the photos below.
Two jumpers attach the Audio Board to the pi-Stomp PCB.
The Pimoroni Hat Hacker should have included 6 10mm metal hex spacers and 12 metal screws. We'll use those along with the nylon spacers for assembling. We'll be using all the screws so try not to loose them.
Attach two 10mm metal spacers using two screws to the Audio Board
They should attach on the edge opposite of the 40-pin header
Attach two 12mm nylon spacers using two screws to the Hat Hacker
They should attach on either side of the edge 40-pin header (male pin side)
Attach two 8mm nylon spacers plus 1mm nylon washers to the Pi using two screws.
They should attach on the edge opposite of the 40-pin header. The stack results in a 9mm spacer.
The four boards should look like this.
Stack the Hat Hacker onto the Raspberry Pi. Seat completely and attach with two screws.
Stack the Audio Board onto the center 40-pin header of the Hat Hacker. Attach with two screws from below. Note that since the audio board has a short header, there will be a slight gap (~2mm) between male and female headers.
Stack the pi-Stomp board onto the main Hat Hacker 40-pin header. Seat completely and attach with two screws.
Connect the 3-pin Audio Board Input cable to the pi-Stomp board. Each pin is labeled on each board with “L” for left, “G” for ground, and “R” for Right. Make sure you connect like pins.
Similarly connect the 2-pin Output cable. It only has “L” and “R”, no ground.
Plug the LCD into the pi-Stomp board 9-pin header.
That's quite the sandwich, eh?