DIY Datamaster Cable Write Up / DIY Kits

[PPI Typhoon]

****EDIT: The potential is high that I could be making DIY kits and even assembed kits for those who would like. Please read the post further down and reply or PM me if you have any questions. ****

Ok, I started off doing a redraw of the schematic for those who are not familiar with schematics. Please be aware that this is a redraw of the adapter on www.techedge.com.au, but with a slight modifications for our purposes.

I also drew it in a "physical layout" to show how it all connects.

*Please excuse my crude drawing*

I color coded the schematic to help explain how you read and interpret the drawing.

I'll post more pictures describing the symbols and what they mean as soon as I chop up the picture.

 

[cartman007]

Thank you AGAIN!!!

You wouldn't happen to have a parts list too would you? That way I won't miss anything while trying to get them down while writing out my own parts list. I am probably going to attempt to make one this weekend. Thanks again!

 

[PPI Typhoon]

This is the heart of the circuit, the IC, or integrated circuit. I have included the pin numbers showing how they are counted physically on the chip. The small dot in the upper left is actually on the IC when you get it (sometimes a notch), but this shows where pin 1 is. When looking at the IC, having the notch/dot at the top, your top left pin is always pin 1. There are other package types and that previous statement doesn't always apply, but it does for our application.

This is a polarized capacitor, meaning that you cannot install them backwards, or they will not work! The + denotes the positive lead. In *most* consumer-purchased capacitors, there will be one lead slightly longer than the other.......this is the positive. I used tantalum capacitors in this application for the polarized caps.

This also is a capacitor, but non-polarized, I chose a ceramic for this application. It doesn't matter what direction these are put in.........hence the non-polarized.

This is a a diode. As you notice, I have not labeled them, but I used the part number: 1N914 diodes. You'll notice the line at the end of the triangle. This denotes the negative terminal, and there is actually a stripe on the diode that is represented by this line. It is important that you install them with the right polarity or your circuit will not work.

This is a resistor........they are not polarized. The type we use are 1/4 watt, as this is a very low current circuit.

This shows connections. I color coded them. Green is the ALDL connector. Blue is the serial port DB9 connector. The text inside shows what connection is made to those connectors.

When you see the dot, that means there is a connection (or a t-off of that existing line). This is just done to prevent any confusion whether or not you make a connection here.

This curve over another line means there is NO CONNECTION to the line it crosses. It just means that you cannot draw the schematic without crossing over another line. Remember, you DO NOT make a connection here.

This is a ground symbol. Hopefully you know this. This can be a common point on the board, a common trace, etc. That way you can ensure that you're all grounded when you need to be in the circuit. If you do not pay attention to these, the circuit WILL NOT WORK.

This is the voltage regulator. This has 3 pins coming out and it is important to make sure that you run the right parts to the right pins. I'll explain more about this later.

Now, in the schematic. You'll notice there are red lines. I colored these red to show you what connections you make manually on the circuit board. Typically, on a proto-board (the universal circuit board you get at places like radio shack), these are made with jumper wires. On a normal circuit, these would be traces of copper.

Ok, I'll post this and we'll get more into the circuit and parts.

 

[PPI Typhoon]

To help illustrate what I mean by a proto-board......this is what you can purchase at Radio Shack.

I didn't use this board personally, but it would work for our application. I didn't require such a small board, so I went with a slightly larger board. However, it doesn't matter. What matters is you make the connections as necessary (which you can see you can put a wire/part just about anywhere. ) These parts are about $1.80 at my local RS. Pretty cheap, and you COULD make two here (you see you can spilt the board in two)

As for a part list. That is as follows:

(1) MaximIC MAX232 (or equivalent, as my local shop cross-referenced it with part IC232, and it works fine)
(1) 78L05 5v regulator (or equivalent......)
(3) IN914 diodes
(1) 1kOhm (1000 ohms) resistor 1/4 watt
(1) 22kOhm (22,000 ohms) resistor 1/4 watt
(1) 0.1uF (pronounced microfarad) ceramic capacitor
(5) 1.0uF tantalum polarized capacitors
(1) DB9 Female Connector (I used the crimp type)
(1) Project Box (most RS boxes come with a circuit board in it)
(1) Circuit board if needed (make sure it fits your project box!)
(1) Cabling for connecting to ALDL connector.....I just did a 2 conductor ribbon cable from RS, but you can use anything really
(1) Roll of 22awg solid connecting wire (you won't use much, but this is used for making your "traces" on the board, or as referred from here on, jumpers.

I think that's it.....if I remember something, I'll edit the list.

Edit: You will need a soldering iron/solder and some misc tools such as pliers and little cutters to clip your leads once soldered in .

 

[PPI Typhoon]

First step in construction is you want to place your IC in a somewhat central location on your board. (note your circle showing pin 1)

I don't have the stuff here at work, but I can draw them really quick.

You can go ahead and solder this in place. Generally in construction, you want to start with the lowest profile parts and work to the highest profile.

 

[PPI Typhoon]

Now you can start either adding your resistors or caps. I did the caps, but you can mix up the order if you like

Notice in the picture that the placement of the parts is much like the schematic that I drew.....

Make sure that you put them in the right way!! REMEMBER: The longer lead is the positive lead. Double and even triple check before you solder them in.

 

[PPI Typhoon]

Ok, where this left off, my 3D Studio Max crashed on me :x

But I'll continue the text and try to add pictures later.


The next step is that you'll add your other low profile components such as resistors and diodes. Remember that the stripe on the diode is represented by the stripe in the schematic. Resistors don't care which way they are inserted.

As for the resistor values, you'll notice color bands. I'm not going to go too much into the theory of color codes, but I will tell you what to look for.

The 1kOhm resistor is going to have the following bands:
Brown, Black, Red, then gold or silver (this isn't too much of a concern which it is in our case)

The 22kOhm resistor is going to have the following bands:

Red, Red, Orange, then gold or silver (again, doesn't matter which you have).

Remember: Right now you're only placing the components on the board, not interconnecting them yet.

You'll probably want to leave the 78L05 Voltage regulator until last since that's one of the larger components.

You can also mount the remaining two capacitors. Remember that the ceramic 0.1uF capacitor doesn't have a polarity, so you can put that in either way, but the last tantalum cap DOES have polarity, so pay attention to that.

Reminder: Longer lead is positive

Lastly, you're looking at the 5V Regulator, 78L05 (or equivalent)

You might be asking, which pin is which? Well, when looking at it, you're more than likely going to have the package that has a rounded side and one flat side. If you hold the part in front of you, legs facing down, flat side toward you (it'll make sense once you see the part), then the pinout going from left to right is:

Input.........Ground..........Output.

So, looking at the schematic, you'll notice that the orientation on the board would be with the flat side facing away from you. The voltage is coming in through those two diodes and out through that ceramic disc cap.

To be continued:

 

[MadPSI]

Damn, I'm sure glad you got another Ty... It's great to see people share information to further advance performance of even the "layman" SyTy community...

We have to compete with the turbo Dodge guys somehow...

PPI Typhoon = LINUX for SyTys...

 

[PPI Typhoon]

Damn, I'm sure glad you got another Ty... It's great to see people share information to further advance performance of even the "layman" SyTy community...

We have to compete with the turbo Dodge guys somehow...

PPI Typhoon = LINUX for SyTys...

Yeah, I'm glad I am back with them too. I'm really into DIY projects and my truck can be the outlet for that.

I just want to help encourage the sharing of information. I see so many other boards that do this, but I don't have those other cars, I have a Typhoon and a Neon. Take a guess which I want to focus my attention on? :lol:

I don't think this steps on any toes for the cables as the information is out there already (which is where I got it), but I haven't seen very many people do it with our trucks. Hopefully I can help dispell any fears that people have for getting their own hands dirty in such a project.

Judging on all the emails and PM's I get about the cables, it's definately worth the time.

 

[PPI Typhoon]

Now, when you flip over the board, you'll notice that everything is soldered in, but nothing is connected.

I did a quick mockup to show that (darkened the board to show the solder better).

What you need to do is bridge the two contact points when needed (if you notice, when there needs to be a connection, I put the legs of each part close to, if not right next to the adjacent component so that you can easily bridge them.

This is accomplished by either establishing a solder bridge (using excessive solder and brushing the iron between the two points making a connection). The better, and more reliable way is to use a small piece of soild wire and solder it in between the two points. This is where all that excess leads come in handy that you cut off after soldering each component in. You can actually cut them to length and use them as the wire to connect the points.

Where it isn't logical to use a bare wire (distance, routing, etc), you can use that 22awg jumper wire that you got. You can physically place a trace from one component to the other with that wire. Once the wire is soldered in place, you can connect each point to the component you're trying to attach it to. Again, you can recycle your cut leads for this.

 

[PPI Typhoon]

I will try to get the rest of the drawings up later, but to complete your project, you'll need to finish interconnecting everything as shown in the schematic.

As a reminder, the red lines in the schematic show that you need to solder a connection between these points.

Once you have all your connections made. Double and triple check your work. This is important becaues the more wires you stuff into it, the harder it is to navigate around the board.

(Note: This is why I used the larger board, just for ease of construction. But as you noticed, you COULD use a much smaller board and cram it all in. I chose not to for my application, but this is up to you)

Once you have all your connections made, the only thing left is to hook up your DB9 connector, your ALDL wires, and mount your project in your project box.

What step I did next was to connect the DB9 (or serial) connection. The reason for this is that you can test your circuit once this is in. I'll explain more of that later.

When it comes to the pinout of the serial connector, this can be a bit confusing. (what way am I looking at the connector? What is pin 1? etc)

Take a look at the serial port on your computer. You'll notice it has 9 pins, 5 on the top, 4 on the bottom.

When looking AT the connector on the computer, reading from left to right, your pinout is:

If you orient yourself to this and go through your pins one at a time, it will be less confusing. Note that you are only using 6 out of the 9 pins. You can leave the unused pins blank on your connector. This will also make for a cleaner overall circuit because as you may have noticed, it's starting to look like a rat's nest with all the wires hanging around.

Going off the schematic, connect each wire, one at a time, to it's appropriate place on the board.

Here's the cool part. Once your connector is on, you can actually now test your circuit without even hooking it up to your truck, nor do you need any test equipment. Obviously if you're building this, you have a computer. You can test it from your computer.

-Connect the serial port to your project.

-Open up Hyperterminal on your computer (this is usually, START > ALL PROGRAMS > ACCESSORIES > COMMUNICATION > HYPERTERMINAL)

-Create a new connection (this is a step by step through a wizard). You can call it anything, but you just need to make sure you're talking through COM1, and your BAUD rate is set to 9600.

-Once your connection is made, it will bring you to a terminal screen with a flashing cursor. IF your circuit is working, you can type in that window and you'll be able to see what you type. If not, then your circuit is not working correctly.

For those wondering, this is how I found two problems with my construction. I accidentally grounded the wrong pin on my MAX232 chip and a bunch of jibberish showed up on my terminal. I found that I made the mistake, and once corrected, the jibberish stopped. HOwever, I did not see anything I typed.

Now the funny part is that I actually also found out about grounding that pin 10 through the resistor by using hyperterminal too. In all my years of electronics, I learned a little trick for building circuits. Your FINGER. The human body has a certain resistance value and capacitance. If you notice, the IC MAX232 is the only "active" component in the circuit (if you don't count the 78L05). So I placed my finger on the pins of the IC while typing on the keyboard. At one point, I actually saw my typing on the terminal. I looked where my finger was..............pin 10. I looked at the TechEdge schematic, and noticed that they use that pin to their ALDL, but we do not. I just chose to ground it. VOILA! It worked after that.

Disclaimer: Do not use that above method unless you're comfortable what you're doing. I knew that it wouldn't hurt anything in this circuit, but in others, you can damage the chip and possibly yourself, especially in high current situations. But in all my years, I also never heard of anyone dying from a serial port's 5V........ I just wanted to share how I found that problem.

That's it! If your typing shows up, you're ready to finish your assembly, attaching your ALDL wires and mounting it in your project box.

 

[imported_ty1724]

where are you grounding the circut to? just didnt see that
btw nice writeup thanks

 

[PPI Typhoon]

Ahh, good question, sorry for not mentioning that.

You need to make sure that all connections to ground are a common point on the board. You can run them all to one section of the board and make sure they are all connected.

What they are grounded to is pin-A on the ALDL connector, which is your vehicle ground. That goes to the ground as well as the ground pin out of your serial port. That creates your common ground.

But one trick that I like to do on protoboards is this: Take all of your grounds, and put them into a line along the edge of the board in consecutive holes. Once all of them are soldered, I take a piece of my solid jumper wire, remove all of the insulation and just run it up the entire row of all my ground connections, usually even the whole length of the board. That way, there's a "ground bar" along the side in the event that you need to add anymore grounds later on, it's easy to do.

If that doesn't make sense, let me know and I'll try to get up an illustration.

Thanks again for pointing that out.

 

[PPI Typhoon]

Ok. With all the questions I've been getting in emails, I've been thinking.

Would people be interested in a "DIY kit" for ALDL cables?? I'm going to be making the circuit boards rather than using protoboards. But I could come up with a kit that basically consists of the board, and all the parts to make the converter. Would people be interested in that?? I could also have an option for a few bucks more to have it assembled and tested so it's just a plug and play.

I'm assuming that the costs would be pretty cheap. I have to see what the costs are to make the boards (shouldn't add but a few dollars to the price), so I'm figuring you can get into one of the kits less than half of what the cables are going for now.

Would people be interested in that?? If so, I can make up a few boards and see what you all think. Basically, the kit would include everything to make the converter. All you would have to do is use a serial cable (if you wanted, or you'd just plug the whole box into the back of your computer, as it wouldn't be very big), and then a two-conductor cable for interfacing the ALDL.

If interested, post back and I'll see what I can come up with.

 

[imported_ty1724]

i may be interested in a diy kit but i would like to see a pic of the finnished prouduct first thanks

 

[kentuc]

Thanks for the 101. You make it easy.

 

[PPI Typhoon]

i may be interested in a diy kit but i would like to see a pic of the finnished prouduct first thanks

Ok, I'll be getting together the materials for the first run this week and should have a finished product by the beginning of next week.

I'll post back when I have more information on the prices and such. I need to work on my bargaining skills and figure out the most efficient manner to prudce the boards and how many at a time.

Again, I'll keep you all posted.

Thanks to everyone for expressing the interest.

 

[PPI Typhoon]

Thanks for the 101. You make it easy.

Sure, it's not all that hard, but I figure for those who don't have the time or sources, a DIY kit or even a final product for cheaper would be a nice alternative.