limeyboy

Cross posted from Norcalevo.net as some of you probably dont have logins there.

This is a howto and journal of my experiences of the JAW wide band controller from 14point7.com. I dont have time to write it all up today, so its going to be a multi part write up!! Im going to assume if you are attempting this you have some kind of electronics experience.

The unit is $45 unassembled, $80 assembled. Theres a screen module for $25 unassembled if you want a readout. I took this option, even though the unit can log directly via your stock ECU. The bosch o2 sensor you need to source elsewhere. they are around $50.

Items were shipped on 3/12/08. Items arrived on 3/18/08. Items were shipped in good strong packaging, however there were literally just components and circuit boards inside an anti static bag. The instructions and operating software can be found on 14point7.com, inside the JAW deploy package.

Components received:



Construction:
You will need - 'No clean' thin Solder*, Soldering iron (i used a 30w iron), small wet sponge, good lighting, at least some kind of soldering experience. Its a good idea to get a small tip for the soldering iron, and use some small gauge solder.

*The solder should be of the no clean variety as it will allow for better joints between component and board. I estimate about 1.5 hours, and 2 burns on the hand, for an amateur solderer to get this unit completed.

First things: Check components are all there. Nothing worse than getting nearly done to find something critical is missing.

Next : Solder the smallest, flushest components first. Sounds really simple when you think about it, but if you solder the bigger components first, when the board is upside down, its difficult to get it level or stay still as its pivoting on those components. I recommend the following order:

- Resistors
- Inducer
- Diode
- IC chips
- Caps
- The rest

It should be relatively easy to figure out which components go where, most are marked on the board itself. Coupled with the manual, component and circuit diagrams, this is by far one of the easiest electronic component kits I have assembled. I did find there are a couple which are not marked - R4 is one of the 5k/4.7k resistors, R11 is the 62 ohm. L1 is the inductor (looks like a fat green resistor)

The resistors can get soldered in any direction on the board, as can the inducer. The IC chips, capacitors and others need to be soldered in a certain direction. Each IC chip has a notch on top (semi circle). This should line up with the one on the board. You may need to bend the IC pins a bit to make it fit int he pre-drilled holes. The one diode has a stripe on it, that stripe should match up with the one on the board (stripe to bottom).

limeyboy

unit was completed this evening. Took about an 90 minutes in total over yesterday and today. The burn prediction was out though - just the one received so far

The flush components were first, resistors, diode, inducer. I then did the IC's. I always try to use a heat sink on IC chips when i solder them, as they tend not to react too well to heat. During soldering, I panicked a bit and thought I had linked pin 14 and 15 of the lm342, however upon closer inspection this looks normal (theres a small track there).

Next up comes the blue connector for the wide band, power and analog outputs. I soldered this all as one, though it can split apart into different pieces if you wish to solder them that way. With this connector, its an idea to use a bit of cardboard to hold it in place as it takes quite a bit of heat to solder down. This could conduct through the connector terminal screws into fingers.

I did the capacitors next. Check the micro farads "uF" on the side of each capacitor and find its indicated place on the board. Each cap has one 'leg' longer than the other. That longer leg goes in the side marked "+" on each capacitor space on the PCB. They also have a stripe on the side of the capacitors which indicates the negative (-) side. Once all soldered, they should all be in the same direction



Solder in the com port (rs232 serial port). The teeth connectors should hold this in place nicely. Next, the rectangular IDC connector. JP1 is marked on the PCB, this indicates where the triangle symbol on the outside of the black ribbon connector (IDC) should go.

lm7805 insert with metal backplate facing the outside of the circuit board.

lm317: screw into heat sink:



It may take a bit of pressure to move the screw in. use heat sink compound between the 317 and the heat sink (if you have it). This should be fitted to the PCB in the same direction as the lm7805 - black side towards the other components, metal away from the other components.

Congratulations on your completed JAW wide band controller. Pop it into the anti static bag for safe keeping and go grab a cold beer.

Heres the completed unit with the display components waiting to be assembled.



Tomorrow will be display soldering, cable construction, calibration and testing. I will try to get something up by the evening.

limeyboy

I purchased a 'settings saver' from autozone for $4.99., Its basically a cig lighter plug for the car with a clip on the end for a 9v battery. The plug im going to use to power the unit in vehicle, but the 9v battery and clip gave me the opportunity to 'dry run' the unit without the sensor attached.

Success!!



As you can see, the unit works, however a slight quirk is that the 9v battery is only just enough to power the unit + display. AS the battery drains, your display will go from 14.7 to 14.77 to 14.9 and so on. I confirmed this by removing the display, and the unit stayed at a constant 14.7 per the datalogging channel (serial). Im going to guess that running with a nice car battery with enough amps is going to deal with this one.



----

Ive been trying to box the unit, make connectors and cables etc. I also did a duh and broke the camera, so im stuck with camera phone pics for now. Sorry!

Heres my box, fitted with power connector. Power connector has an inline 3Amp fuse (in the cig lighter socket adapter) and each wire is rated for 5Amps and is covered with the plastic flex wire conduit. The conduit runs directly into the unit (non detachable) via a gromit and some cable ties. Nice n secure. The red and white clip connectors on top are for ground and Vout(1) for NB simulation.



I also made up the wire to connect the sensor to my box, alos covered with the black flex conduit. This connecting cable used the JAW "economy" method, which involves using spade connectors to interface with the sensor. I have put a radio shack 6 pin connector (white) on the end, so that I can detach it from the controller box as I require. Each wire in the cable is rated for 3 amps. All the wires in this cable are the same color, so I had to use a continuity tester to ensure the correct pin goes to the correct pin. Secure the spade connectors into the Wb sensor with some tape and cable ties.



Im going to add a fan to the box for cooling that heatsink, and then I have to get the display all hooked up and mounted. I suppose I could technically have had this running already and fed some results back to you guys, but I would like to ensure the unit is secure and not going to be affected by short circuits etc.

limeyboy

I got the construction of casing and wiring all completed. Heres the unit upside down with the fan installed and the wiring loom installed. Sorry for the crap pictures, as I mentioned earlier, the camera is out of action. I will probably get some laughs for using all red wire, but if you are careful and know which wire goes where, then it doesn't really matter which color you choose to use. I mark them all with white tape at the end normally, 12v, gnd, etc etc.



I mounted the 12v fan to the side of the unit (which is at the top in the picture), with some aluminum screen repair square mounted over to ensure no crap gets into the unit. It needs it to cool of that heatsink. I used a 12 computer fan. Cools it great. I also made an exhaust port over where the heatsink is, again covered with the aluminum screen to keep crap out.

You can also see the white connector sticking out of the left side next to the power loom, this is where the sensor wire connects from the previous post. Theres also an rs232 connector which is hidden from view on the right hand side

Heres what it looks like the right way up



Notice the four dots on the top? This is where the display LCD was going to sit. In my haste to construct the unit and test it, I didn't mount the display connector in the correct orientation, so there was no clearance to mount it to the case. I attempted to desolder the connector, but fat fingered it and broke a track or two. i tried bridging with some patch wire, but whatever I did, the display refused to come back. Well at least we know the unit was good and working before I busted it, so another $25 will be going off to buy the display again.

Until then, I will have to make do with logging via Evoscan ;-)

limeyboy

Success!

The unit has been free air calibrated and the sensor is showing the correct parameters. The manufacturer states that if the AFR reading goes from 14.7 at power on (with the sensor attached), to 34.28, along with the heat value dropping from 255 to 16 (all while in free air), then the unit is functioning and the sensor appears good. At this point, free air calibration may be performed and written to the unit. Oh, and dont pick up the o2 sensor, its kinda warm.

Here is a pic of the unit operating via the cig lighter, with laptop attached after free air calibration. Its kinda small, but you can see the readout for AFR (top) and heat (16)



The Evo is off for a new clutch tomorrow, im hoping to try to get some datalogs with the unit running, Ill post them up if I get time to do them

EvoBroMA

i love DIY but i am not a fan of his design. he has a new design he is working on, though that does look promising, but it will be less of a DIY kit.

FYI, the JAW is not .01 lambda accurate. If you ask him about it, i'm sure he'll explain why, but the jist of it is that he loses alot of accuracy in his A/D process away from stoich. many wideband controllers claim .01 accuracy because of the Bosch sensor - but also have innacurate A/D processes.


Zeitronix, and Innovate designs are pretty close though. Its tough to find a nitch - in the Evo community because most of us would rather not cut corners and get the best for our car. And with all the time and work you just put into making JAW work for you, the savings are marginal for a mediocre wideband setup.

tabio42

iTrader: (15)

I would like to use that display to read AFR from a 0-5v input from another controller. Anyone with electrical skills know how to do that?

limeyboy

dexmix:
interesting, ill MSN Alan and ask about that inaccuracy, but from reading your post, you are implying that other controllers also have this same issue (but claim 0.01 thanks to the sensor)?

EvoBroMA

its not the same issue, but they similarly claim .01 accuracy - but the clause is that its only close to stoich. his design is especially innacurate because of the A/D process. the design was made with a DIY budget in mind so i feel like he cut alot of corners to keep the cost down. just my opinion though. As a fellow EE - its not something i would run on my car. purely going by accuracy - because i am also not a fan of his heater circuit. another corner was cut to save cost and simplicity.

limeyboy

thanks for the info, valuable to me. What I will do is log my cars AFR with the JAW and then after its tuned, Ill log it with a commercial unit to see if there are noticeable differences. I will feed that back here.

EvoBroMA

that would be perfect. that way others can see the accuracy and decide if the price makes it worth it to them.

another caveat of the unit is the heater control. he uses a linear regulator to power the sensor heater, (thats the guy with the big heatsink) if you check the datasheet of the regulator to see how much power it can source, you'll see that its well under the max current draw of the heater in the Bosch spec. for comparison you will find that an LC-1 draws close to 5 amps, on heat up. i do not believe he put in any provisions for when his sensor temp is out of range, which it will be for a while until the LSU heats up to operating temp. as long as your car is warmed up though this shouldnt be a problem, especially on the Evo, with its decently warm EGTs.

limeyboy

I spoke to the creator of JAW. While dexmix is correct, older versions didnt have very good resolution, firmware after version 1.09 will have resolution of 0.01 Lambda

The creator of the JAW also admits that yes, resolution will decay from 0.01 in leaner scenarios, but this really shouldnt affect us WOT tuning EVo guys. Why?

So yeah, odler firmware sucks, but anything newer then 1.09 seems to be ideal for us Evo owners aiming for the magical 11's. I dont intend to go for an AFR higher than 11.5 for my WOT tunes, and resolution is 0.01 lambda there, so im happy.

I will still compare commercial and JAW unit too!!