Forgot your password?
No account? Register one!
January 9, 2008
News - Product Assembly at Spark… |
about a year ago
Is the red bow tie CGI? It looks kind of electric.
News - Surface Mount Soldering w… |
about a year ago
I’ve found that SMD soldering is incompatible with coffee consumption. ;-)
Product TOL-10622 |
about 3 years ago
What color of smoke refill do I need if the TGPIFS itself blows up?
Product TOL-10240 |
about 3 years ago
Ok, I purchased a sample length of this. Still interested in finding an answer to the Antimony question. Is there an MSDS sheet for this?
I’m considering trying out this solder but I have a couple of questions -
1) Is it easier to use than the stuff with a higher percentage of Antimony? I’ve had bad luck with cold solder joints on another brand of lead free solder.
2) Is it safe to handle with bare hands? Antimony is pretty toxic, right up there with arsenic, but I don’t know about a product with a .15% percentage of it, and whether it’s less toxic when when it’s bound to other elements in the product.
Product CEL-09607 |
about 3 years ago
Will this shield work on the Verizon network? From what I can tell, Verizon uses 800mhz and 1900mhz. I don’t see 800mhz as being supported in the data sheet.
The problem is that Verizon doesn’t use GSM, and only GSM phones use SIMs. The major GSM players in the US are AT&T and TMO.
Ok, I’m working with the 5100B development board and one problem is driving me nuts - I cannot get a signal.
I’ve set the SBAND command to 7 (USA) and set the module to automatically select the network (AT+COPS=0). I’m using a SIM card that worked in a GSM phone, and I’ve tried two different GSM antennas from Sparkfun. And I’m using it in an area where the phone says there is adequate signal, yet an “AT+CSQ” command always yields a 0,99.
I’ve checked the antenna connection for continuity and shorts - no problem there.
I’ve tried running the module directly from a fully charged LiPo cell as well as from an external DC supply, so I don’t think it’s a problem with the current draw.
I’m communicating to the module via hyperterm on a PC and I have no trouble getting it to respond to other commands.
I measured the output of the regulator chip and got 3.98v (just double checked it).
I’ve rechecked the antenna leads again. No shorts or opens. I’ve also run through all of the SBAND= options with the same results on every band. I’m starting to wonder if I have a bad module.
After monkeying with the antenna cable a little bit, I’ve discovered that I can pick up a signal if I position the wire leading to the module’s solder joint vertically rather than letting it lay horizontally across the module. Thus there appears to be something funky going on with that solder joint. It’s worth noting that a connection that tests fine at DC could easily fail at high frequency ac.
Now that I have a signal I can’t get it to register. I keep getting a CREG=3 (denied).
Issuing an AT+CPIN? command returns with READY, so I don’t think there’s a PIN issue. Is it possible that the carriers are blocking the IMEI hardware addresses of these modules?
Turns out that the only GSM towers that I can receive here are from TMO, and I was using a SIM casrd from oan AT&T reseller, H2O. Apparently th ere is no reciprocal agreement between the two carriers.
So I took the unit a few miles away where I got a strong signal from an AT&T tower and it registered immediately and started working. I was able to send an SMS test message successfully from this location.
Back to the antenna connection issue -
When I resoldered the cable to the connector pads on the module, at first I had NO signal at all. So I removed a bit of the solder, leaving a smaller, flatter solder blob on the center-pin contact and this time it worked.
I’m guessing that a solder blob that is a bit too high can detune the antenna circuit by creating an impedance bump at the solder joint. While there’s no way to avoid a small impedance bump at the solder interface, it appears to be critical to minimize it as much as possible, especially since the PCS band is running at microwave frequencies.
The more you know…
News - Retail Packaging Has Arri… |
about 4 years ago
I do like the professional look of the hard plastic packaging, and if this is what it will take to get the products into more stores, so be it. I still prefer the soft plastic bags and cute red cardboard boxes though. I’m storing most of my projects in those boxes ‘cause it makes them easy to spot when I need them.
I’m really looking forward to seeing Sparkfun products in more brick & mortar locations. Hobby shops are a perfect place, and it would be one more reason for these shops to stick around in an ever more competetive market. The world needs more young scientists, and thus more hobby and electronics stores to present them with opportunities for inventing!
I was pleasantly surprised to see an Arduino section at a local computer store in mid-Ohio. They had most of the items packaged as a plastic-bag-within-another-plastic-bag, with the store’s SKU placed on the outer bag. That didn’t make a lot of sense to me but I guess it was the fastest way for the store to get everything into a standard-ish pegboard-friendly package with their SKU on it.
The clamshell packaging will certainly jazz up their store display, although there is something to be said for the simpler packaging in terms of looking more hobbyist friendly and grassroots in origin.
I wound up buying a couple of Arduinos there, not because I needed them at the moment but just because I could grab them now and have them available when the inspiration strikes.
No public wish lists :(