Put to the test!

A brief update for today:

The four CNC machined housings arrived this week and all of them make a nice fit as you can see in the photo (I masked off the LED opening with some tape to simulate the lens effect as those lenses were to small to be CNC'ed). I have been in touch with the housing manufacturer this week as well to iron out the last details of the drawings. They will start cutting steel upcoming week! Once that is done, I will visit them to take a look at the molds before we get our first parts.

I built three additional GPS modules this week as well and the new upload tool for A-GPS data from the manufacturer seems to work a lot better now. After having uploaded the latest A-GPS data to each of the modules, I have performed open/clear sky testing with the modules and am very happy with the results! Typical time-to-first-fix (TTFF) with A-GPS enabled is ~10sec average on a cold start. Average signal-to-noise-ratio (SNR) is ~42dB (note that both the TTFF and SNR numbers are open/clear sky numbers and can vary in practice depending on surroundings and GPS satellite strength). Performance is thus very good for such a small unit! After the antenna tuning process, we might gain a little more on the SNR, but we will wait for those results first before concluding anything.

I also had to place a special purchase order (PO) for the high brightness/low current bi-color LEDs this week as they only had 200 in stock (delivery is scheduled for September 15, 2008). As I thought the green/orange color combination was a little too ordinary, I have chosen a blue/red LED which looks really cool. The blue LED will be on as power-on indicator and the red LED will flash when searching for satellites (it will be off after a GPS lock is found). So while searching for satellites, the combined blue/red LED will flash purple. Power consumption of the LED will be a little less than 1mA when the module is tracking. The rest of the module consumes ~36mA while tracking for a total of 37mA for tracking.

Power consumption, size and performance have all been traded off against each other, but it looks like the final results are pretty good in my humble opinion!

The estimated-time-of-arrival (ETA) for the modules is still set for the end of September. Let's hope there will be no further delays; thanks everyone for hanging in there!

What's (been) happening?

It has been a little while and as you can imagine things have been busy and very hectic. Here is an update on the various items:

1. Last Monday, the last revision of the PCB came back. Although I placed it as a rush order, it was late; it was supposed to have arrived the Thursday before. In the meantime I have built a new GPS module with it and tested its performance, which is up to spec now. This new module is shown in the photo (inside of the new housing prototype).


2. The biggest milestone that got done this week is the new two-piece housing design. This has pretty much kept me busy full-time since last week:
• New 3D CAD files (no logos) were completed and a new FDM prototype was made to verify that everything fits inside of it. I painted the prototype black, put the latest board inside and hooked the USB cable up. The result can be seen in the photo.
• The next thing in line was sending out the new 3D housing designs to get real prototype housings CNC machined out of solid ABS plastic (no FDM). These are needed to do proper antenna tuning of the board and the housing for optimum GPS performance. These housings are expected back upcoming week.
• Next I had to finalize the drawings for production and place the logos on them. This did not go without hick-ups and quite some time was waisted trying to get the 3D software to accept the graphics files. But eventually I managed to get everything imported.
• I am currently detailing the lens a little more to make sure that the LED light comes out properly and has a wide viewing angle. The final CAD files are due first thing Monday morning.
• A purchase order (PO) was placed for the injection mold making and a delivery of 1000 housings. The housings are to be completed by September 9, 2008.


3. I also received new GPS modules with updated firmware for this new PCB design. I had problems uploading A-GPS data to them. I thought it was a firmware issue, but after talking to the GPS vendor it turns out that the A-GPS upload tool that they provided had some problems, so they provided me with an updated version which performs better but still seems a little buggy. After we get a final OK from the vendor on the module configuration and firmware, we can place a PO as well (I hope this can happen this week).


4. Regarding contract manufacturers, I have converged on a candidate for PCB manufacturing and assembly with competitive pricing. I might have to make a few minor adjustments to the bill of materials, but after that we can get the ball running.

It looks like the Orange Gadgets website has been running pretty smoothly. As of now, 177 people have signed up so far for a total of 208 modules. Feel free to do some additional advertising among your family and friends as well as online.

Micro USB cable samples have arrived!

I have received three samples of the USB-A to micro USB-B cable. The cables are 6ft long which should be plenty to hook up to your module from wherever you want. I have already tested all three cables with my modules and they are performing fine, including syncing of the iPhone from iTunes.

I will give you a brief progress update so you know where we are at:

• Housing: A housing manufacturer has been found. I have visited him twice and toured the facility and liked what I saw. They have also been very helpful in getting the housing prototypes done. I will be updating the housing design next and after that get a revised quote. Mold making will take 3-4 weeks ARO and then the first parts will be delivered one week after mold approval.
  
  
• PCB board assembly: I have received about half of the quotes that I requested. The remaining ones are expected by the end of this week. Typical lead time for 1000 units is about 4 weeks (this includes PCB fabrication and assembly).


• PCB board re-spin:Just today I sent out another PCB prototype board design that will address the somewhat lower performance on the last set of prototypes. This board is expected back mid next week. By the end of next week, I should have build another three prototypes with these new boards and have tested them for performance.


• USB cables: USB cable samples have been received and tested. An order will be placed tomorrow. Lead time is 6-8 weeks.


• Other: Some other things are running in the background in parallel... I'll keep you guessing at what that may be for now...
  

The Good and the Bad...

The photos show two rough prototype housings made on a fused deposition modeling machine (FDM). As the resolution of these machines is about 5-10mils (127-254um), the surface of the housing is not very smooth, but it is good enough to do form fitting of the board and dock connector. Also, the housings look white as the machine uses this color plastic to do the FDM. The ultimate housing will be black.

The next photo show you how the module will look on both the iPhone and iPod touch.



Now for the good news:

• All the clearances for board to housing were designed correctly and the boards fit nicely within the housing.


• I have also received the A-GPS modules in the meantime and built a new module with it and put it to the test. The way it works is as follows: you first download 7 or 14-day valid data to the module (this can be done through software), then use the module as normal. I have put this module to the test and compared it with a module without A-GPS. For the A-GPS module, the time-to-first-fix (TTFF) in open sky after a cold start was reduced from 43sec to 29sec (average over 5 measurements) with times as short as 16sec.


• A large volume of dock connectors for the modules have arrived!


• NDAs have been put in place with quite a few PCB contract manufactures and quotes are expected back soon.

Now for the bad news:

• It turns out, there is no way to get the plastic lens into the LED opening of the housing and have it sit straight and tight. So it's a good thing to have built these prototypes to do form-fitting before getting a housing injection molded for real. We will have to come up with something to solve the lens problem: the housing will be split in two half so that the lens can be inserted from the inside and the wall can be thickened locally for a straight and tight fit.


• Recent testing has revealed that the latest prototypes lack a little in performance compared to the earlier prototypes. A re-spin of the board can remedy this and will bring you the best performance possible (note that one board design is currently still in the pipeline and is expected back later this week for more performance testing). This will delay things a little, but not too much (about a week).

As you can see, this project is keeping me busy full-time, but all aspects of the project are progressing very well in parallel.

Software compatibility with RoadMap

Link for iPhone and iTouch users here.


Before we discuss the video, let me first mention that we hit 2000 votes yesterday!

This is again great news and I will update you on the manufacturing progress in a separate post (I have been very busy taking care of all the logistics behind the scenes and acquiring quotes for the manufacturing now that NDAs have been signed).

The video above shows a demonstration of the open source software RoadMap. This open source software was ported to the iPhone by Morten Bek. Of course it is a work in progress and not everything is perfect yet and neither are all features ported, but at least it shows the concept and future potential: 3D real time location mapping (with local maps on your iPhone/iTouch; no need to connect to the internet) and hopefully in the (near) future full voice-assisted navigation support.

I was very impressed by what Morten has accomplished so far!

It seems there are two branches of the RoadMap software. The one that Morten is working on and the one that Ehud Shabtai is working on. The second branch is a little further ahead maybe in terms of features, see this video, but unfortunately the language and Wiki for that branch is in Hebrew and it only comes with the map of Israel. Hopefully the two branches will be able to join efforts and converge into one great iPhone/iTouch application.

For Morten's branch, I downloaded all the maps for California from here and I can now locate myself on my iPhone without the need for the Maps.app or internet connection.

The video shows the main aspects of the RoadMap application:

• Arrow icon at left top: this switches between a fixed map view or a rotating map view. In the last case, your driving direction is always pointed upward and the map will rotate along with you.


• Satellite icon: its color varies, green for GPS lock and red for no GPS signal. Pressing the icon will move the center of the map to your current GPS location.


• Satellite screen: provides a view of the signal to noise ratio (SNR) for each satellite, longitude, latitude, elevation, speed, etc. This screen is accessible through the left button on the menu bar in the bottom (hard to see in the video)


• 2D/3D icon: pressing this icon will switch between a 2D view of the map and a more navigation like 3D view of the map (see end of video)


• Zoom in/out icons: pressing these buttons will change the scale of the map accordingly.


• There are some more buttons in the bottom bar, but not all of them are working. With one of them, you can email your currently logged GPS route to your friends.
  

Unfortunately, my video recording ended abruptly as the camera ran out of memory, so the 3D view of the map (which I think is really neat) is not that long. But I hope you get an idea of what it looks like.

Warning.....

That time has come again..... Apple's 2.0 firmware upgrade will be out shortly, so I would like to issue a warning....

To make it clear to everyone, if you intend on using the GPS module on your iPhone or iTouch, make sure NOT TO UPGRADE your iPhone and iTouch firmware for the time being. The same goes for iTunes. Leave it alone till it is confirmed that it is safe to upgrade.

In order to communicate with the GPS module, a jailbroken iPhone or iTouch is required. Upgrading to Apple's official 2.0 firmware will put your iPhone/iTouch back into a sealed environment again until the iPhone Dev Teams comes up with another jailbreak.

So if you would like to keep your options open, play it safe. Leave your current firmware alone and wait till the unlock development teams give you the green light.

Simplified housing design

This week has been a very busy week. What you see above is a simplified housing design for which it will be cheaper to make an injection mold than for the first design. This is important as we are talking about relatively small number of volumes for injection molding (a couple of thousand) and the mold-making cost will need to be kept as low as possible so as not to drive up the price of the module. An alternative to traditional injection molding is rapid injection molding. I will need to look at both options to find out which one gives the cheapest price per unit.

For this latest housing design, the USB connector has been moved to the bottom side of the module. I have updated the PCB layout accordingly. The size of the housing is 26mm x 22.2mm x 9mm.

I have started working pretty much full-time on this project since July 1st. I have drafted up a project schedule for getting the module into production. Quite a few things need to be synchronized in terms of time-line. Here is what currently has been accomplished or is still in the works:

• NDA's have been put in place with various contract manufacturers (CM) for both the PCB assembly and the housing.
  
• The PCB has been designed and is waiting for feedback from the CM in order to determine manufacturability (1-2 weeks; we will be going into the second week). The PCB design might have to be tweaked after we get feedback from the CM. This process is called design for manufacturability (DFM).
  
• After the DFM is completed, a few final prototypes need to be built and sent to the CM (2 weeks).
  
• A few prototype housings also need to be built/machined and sent to the CM (3-4 weeks).
  
• GPS antennas need to be built (1 week setup + 3 week lead-time).
  
• GPS chip needs to be manufactured (4 weeks).
  
• Bill of materials (BOM) needs to be sourced. Some parts have a lead-time (up to 3 weeks).
• Housings need to be produced by injection molding at CM (no time-line available yet from the CM for this).
  
• After all this is completed, usually an engineering pilot build is done for design verification and after that a production pilot build.
• Test procedures need to be implemented and test fixtures designed and put in place (4 weeks). This includes both testing of the PCB as well as a final test of the performance of each GPS module.

As you can see, quite a lot of things need to be managed and synchronized. But in order to bring you the best working GPS product out there for your iPhone and iTouch, no corners can be cut.

I will keep you posted as things progress :).

First design of the housing

Top view:

Bottom view:

I have completed a first draft design of the housing. Here are a few comment on the housing:

1. Take a close look at the Apple design of your dock connector. I have managed to take that connector apart without destroying it. It's a pretty sleek design, consisting only of two parts: a sleeve that goes around the connector and a cap that slides over the connector and inside of the sleeve. I have made the housing for the GPS module in a similar rounded/flat shape as the Apple sleeve. Apple's sleeve is 26.1mm x 9mm x 5.6mm (width x length x thickness). The GPS module housing is 25.4mm x 22.2mm x 8mm. So it is a little thicker as the dock connector and about 2.5 times as long.


2. You can see the micro USB connector on the left side of the module (top view).This plug can either accept micro USB-A or micro USB-B cables. I have found a trust-worthy supplier for the micro USB-B cable and the cable will be included with the GPS module to make life easy :).


3. On the top view you see a small green light. This is the LED indicator that displays the status of the GPS module: flashing orange means the module is searching for a satellite lock. Once a lock is found, the indicator will light steady green. My plan is to make this indicator aperture similar to Apple's MagSafe power adapter that is used on the MacBook.

In the meantime, I am playing with some more ideas to make the housing design even simpler...

Board and chipset update

This is a brief note to give you an update on the board assembly that I started last week.

It turned out that the problem of the GPS chip not sending data was not in the GPS chip itself but caused by my own mistake (:-o). I was trying to get the module together quickly to test the new board, and in the hurry, I didn't solder one of the components onto the board, which left part of the GPS chip disconnected. After a very helpful phone conversation with the chip vendor, we traced the problem down in 5 minutes.

I guess sometimes it is indeed good to take a brief break from everything and let things come to peace; after I soldered the missing component onto the board, everything worked flawlessly :)

And I have another update for you: the next chip-sets that I ordered will be A-GPS enabled!