I just purchased the GM862 Complete Kit, but instead of the temporarily out-of-stock EVK v1 board, I received a rather different board labelled EVK v1a. It looks to be a nicer board in some respects, but I have some problems with it…
What are the connector pinouts? There’s no documentation for this board that I can find on your site. It looks like they might be the same as the connectors on the EVK v2, but I’m not willing to risk the module on that guess.
Solder blobs are NOT AT ALL AN ACCEPTABLE SUBSTITUTE for actual removable jumpers for isolating the module serial port from the USB chip! I expected to switch back and forth between USB and microcontroller interface many times for this project, but I’m obviously going to have to change my plans - those pads aren’t going to survive being resoldered that many times. I realize you probably saved quite a bit on assembly costs by having no thru-hole components, however there looks to be plenty of room for pads for a user-added jumper. (Only one jumper is really needed, it wouldn’t hurt to have the module’s serial output connected to both the USB chip and a microcontroller.)
The solder jumpers are an attempt to ease manufacture. Most users need the EVK simply for evaluation. After a certain amount of time, they may need to test a full blown proto where they will need to disconnect the USB IC - hence the disconnect jumpers.
Spark Fun is growing like a bacteria - we’ve doubled in size, stock, and employees in the past two weeks. Obviously I haven’t been able to keep up with everything - please bare with us. I really truly appreciate the feedback. We want to make dev boards for people - any way we can. In your case, I see now that solder jumpers are a poor solution. If we incorporate an empty 2-pin header footprint for you, you could add the header/jumper on your own. The solder jumpers would be in parallel. I like your solution.
Please let us know how you like the EVK v1a. We are pushing all designs towards the EVK v1b.
The breakout board will be discontinued
The EVK v2 will be discontinued.
The EVK v1b will have both types of jumpers along with full 50-pin breakout and camera support. v1a does not support the camera.
The EVK v1a is working nicely so far, although I haven’t gotten to the point of dealing with the jumpers yet due to an unexpected snag - I picked up a couple of cheap SIM cards on eBay, but have not been able to activate them. Neither Cingular nor T-Mobile appear to offer service in any form other than a complete package including a phone, which I have no use for. I’ll try visiting their stores in person soon to hopefully get this straightened out.
Some other suggestions, if you’re going to be redoing the board anyway:
The USB chip is reporting a current requirement of 100 mA, which is quite a joke considering what the module can actually draw. If there’s some way of getting it to request the full 500 mA (pulling some pin high or low?), that would go a long way towards making the board a valid USB device.
It might be a good idea to connect that unused pin on the serial comm header to PWRCTL, which is needed for the level shifter circuits recommended in the module data sheet. This would allow more applications to make all the connections they need via a single header.
For you and others - there is no need to purchase a SIM card. Bring the module with you - and walk into Cingular or TMobile store and ask for just a SIM card. They’re free and you don’t have to sign a contract because you don’t need a phone. Be sure to ask them to activate all the free goodies they will allow like GPRS (blind internet connection) and CSD (old school analog modem dialing and connection).
Be sure to bring your GM862 - the store people will be totally dumbfounded, but they will feel more at home when they see the IMEI barcode on the unit. They’ll want to scan that and assign it to your SIM card. This is really not needed (you can pull any SIM from any activated phone and it will work) - but this will avoid the silly store workers debating you and scratching their heads.
The CP2101 USB chip can be programmed to provide as much as the USB 2.0 limit of 500mA but it shouldn’t matter. You can download the CP2101-set ID program and reprogram the IC with new current maxes as well as your own product ID.
Really??? I was under the impression that a SIM cost about $25 by itself.
I just temporarily put the SIM in my wife’s cellphone when I went to get it activated at a Cingular store. And yes, they scanned the IMEI barcode on the phone. This could be a problem if it’s a requirement to get service: with my current planned layout for the final device, the barcode on the GM862 will be completely buried inside, no possibility of scanning it. I suppose I could display the IMEI on the “insert SIM” screen.
Again, the IMEI barcode is really just to make the store people feel better about themselves. You could hand them anything including your wife’s phone or a GM862 module that you use for activating all your cards.
I’ve got three cards from various stores for no fee. Well, the $30 activation fee bites, but there is no explicit charge for the SIM card.
And $25 is just a rediculous retail price. In the beginning of SIM cards, it was really actually just a 16F84 inside with something like 1k of eeprom space. Uber cheap. Now they’ve increased it to 64k but it’s just a simple i2c or spi interface with a fancy interface.
sparky:
Again, the IMEI barcode is really just to make the store people feel better about themselves. You could hand them anything including your wife’s phone or a GM862 module that you use for activating all your cards.
This is a device that I hope will be produced in at least moderate quantities. Including my wife’s phone with each device is not really an option…