Fully-detailed instructions for assembly and test of the PIC-EL Kit.
Section 9: CONNECTORS
There are many connectors with this kit, so this section will take a little longer to accomplish.
The first connector to install is that for the DDS Daughtercard, J6. This connector is the 8-pin SIP (single-inline pin) socket, as pictured in the Parts List. It's most convenient and attractive to mount this connector so the optional DDS Daughtercard is parallel to, and slightly elevated from the main pc board. However suitable 90-degree connectors are very hard to come by ... so we'll improvise!
One way to mount J6 is a parallel/elevated position is to use an 8-position pinheader, as shown below. The pinheader from your junk box could be soldered at the J6 position and the J6 socket would be carefully soldered at a right angle to the top of the pins. When the DDS Daughtercard is plugged into the socket, standoffs would hold the board firmly in position.
f you don't have a scap pinheader in your junkbox, you probably could find some stiff wire, like 22 gauge solid conductor wire, to use in its place. Just carefully solder eight pieces of 1" this wire to the terminals of J6, gently to a 90-degree bend in the wires and insert to the pc board at the J6 position. Ensure that your makeshift connector is up about 1/2" and that it's even (parallel to the plane of the board) and solder in place.
An alternative way of mounting J6 would be as shown below. Here the connector is only partially inserted to the board and tipped at a 45-degree angle and soldered in place. Mounting J6 in this manner will put the DDS Daughtercard at the same 45-degree angle, giving appropriate clearance to the rotary encoder closely located to J6. This will give your fingers enough room to turn the shaft of the encoder without the DDS Daughtercard getting in the way.
The next connector you should install is the DB9F serial port connector J2. Some of the connectors come with the little "jaws" in the mounting holes, as shown below, while others merely have a 1/8" hole. If yours is the jawed version, you should insert the connector into the designated position on the pc board and solder the jaws in place before soldering the nine signal pins. This will lend mechanical strength to the connector when complete. If yours is the holed version, you should use some 4-40 screws/nuts to hold the connector in place before soldering the nine signal pins in place.
The next connectors to add to the pc board are the 1/8" stereo jacks, J3 and J8. Be careful not to overheat the pins when soldering, as excessive heat may melt the plastic body of the connector.
Make sure J3 and J8 are mounted flush to the board as shown below.
You should next mount the BNC connector J7. This connector slips comfortably into place with its two smaller signal leads and the two larger mounting posts fitting snuggly on the board. Use the "high" setting of your soldering iron to solder the mounting posts to the pads, as the posts are large and will require some extra heat to ensure that they are solidly attached to the board. These mounting posts importantly give the connector mechanical strength because of the often-heavy RF cables attached to the connector. As shown in the second photo below, make sure that the BNC connector is sitting flat on the pcb. Besides making for a nice-looking project, it will more easily allow you to cut holes in the panel of an enclosure that you might later consider using with the PIC-El project.
The next components to get added are the voltage regulator (U2) and power connector (J1). You should bend the three leads of U2 at 90-degree angles at the point indicated in the photo below. Then insert U2 in the pcb with the flat side against the board such that the hole in the tab of the device lines up with the hole in the board. (There's really not a need to use a heatsink or even screw the device down ... it just looks nicer this way!)
You will find that the holes for J1 terminals are a bit large. That's okay - just make sure the connector is "squared up" to the edge of the board and tack-solder one of the leads first to make sure it stays aligned. Once it's position is set correctly, go ahead and solder the three terminals well. As you'll see in the second photo below, it's not necessary to fill the hole with solder - just make sure that the terminal has a good solid connection to the pad, as illustrated. Just as with the BNC connector, a good connection on J1 is useful because off the stress it will receive when the power plug is repeatedly inserted/removed.
Next insert the IC socket J5. ensure that the socket is oriented as shown, with the notch at the top of the device located at the end noted as "pin 1".
The board-mounted LCD connector J4 is mounted next. Just be careful to have it perpendicular to the board, as shown in the second photo. Also, be careful not to apply too much heat to these plastic connectors, as it could distort during that soldering process.
(BTW, you can see in the photo below that I didn't have a 1/8-watt resistor for R15 during the prototype build and photo session, and therefore had to use a 1/4-watt resistor instead. This is a safety valve that you can also follow should the supplied component fly out of your hands and become eaten by the rug ... just use the next-best thing you have in your workbench!)
The LCD-mounted LCD connector P4 is shown below. It's best to mount the connector as illustrated with the flat plastic piece on the inward side of the LCD. Mounting it this way will allow it to serve as some support for the LCD when inserted into the mating J4 connector on the board.
A properly mounted LCD will not need any support other than what is offered by the J4/P4 combination; however you might want to use some standoffs at the edge of the LCD to hold it up and solid. Holes are provided for this, if desired.
The 2x6 position pinheader HDR1 should be added next. Insert the side of the connector with longer leads into the pcb, solder them from the bottom and then snip off the excess length. Leaving the shorter side of the connector "above board" makes for a more elegant-looking arrangement.
in the same manner, mount the 2x2 position HDR2 and the 1x2 position HDR3 as shown below. Solder in place and snip off excees lead lengths.
Now is the time to add the proper jumpers, or shunts to the HDR2 and HDR3 connectors. Mount one shunt on HDR2 such that pins 2-3 are shorted. Mount the second shunt on HDR3, but we need to leave the signal path open for now so just slip it on one of the pins and leave it hanging off, as illustrated below.
You next need to prepare the 2x6 position SKT-1 for use on the board. You will ultimately place this socket onto HDR1 in order to connect each off the 6 pairs of adjacent signals. (This is an important step ... if omitted or if not done properly, your PIC-EL board will not fully operate.)
You should create these "adjacent pin connections" by soldering a wire (e.g., a clipped lead from the resistors) across the two pins as show in the two views below.
Once one side of each of the six wires has been soldered on, providing a convenient way to hold the in-process work, arrange each wire so it is touching the adjacent pin and then solder it to the pin. Snip off excess lead length and you end up with the result shown in the second photo below.
The two photos below shows the completed preparation of SKT-1. Note how I soldered the wires close to the top of the pins. This will allow me downstream to snip one or more of them and patch in other signals when I want to use my PIC-EL board for other purposes. (This will be explained later on.)
The last step for installing SKT-1 is to insert it onto HDR-1. Again, if this step isn't done, you'll be scratching your head for possible reasons for the board not working!
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Page last updated: Feb 4, 2004