February 18, 2011
Pic Basic Pro
RF, RFID, embedded systems, PCB design, Firmware Development, Specialized Sensors
about 3 years ago
Not sure why what you connect to the switch contacts of the relay should interfere with the usb opration, unless they stupidly connected the Common of the USB section of the pcb to one of teh switch contacts of the relays??? Gnerally a relay should provide decent isolation.
about 4 years ago
Finally, the secret to getting this device to work.
Although it took me a week of frustration, knowing a few simple facts is all it takes.
I will be providing a tutorial that simplifies how to transmit data to a serve, sens sms msgs and make calls later, but for now, here’s how to get connected to a Tmobile network in a minute of two.
I am using TMobile as my carrier. A Prepaid SIM
The ONE most important thing is using the proper antenna. TMobile uses 1900Mhz band in US. DO NOT use a cellular antenna designed for 850-900Mhz. It will not work, unless maybe you have climbed a cell tower and placed it next to its antenna.
Use an antenna designed for 1900Mhz. This is critical.
The second thing is to set your device to the right frequency band.
Use the AT+SBAND=7 command.
Once set, this setting will remain until you change it, even if you remove power from the device.
With proper antenna connected and band set, recycle power to your device.
Wait a bit and you will eventually see the infamous +SIND: 11 response indicating that you are sucessfully connected to your network.
After this, the rest is easy!
More to follow…
about 4 years ago
can you tell me how you set up your device for a Tmobile SIm.
HAving no luck getting the device regeistered to the network. Freq band is set right.
Have you gotten this to work in the US on T-Mobile? If so, what settings do you use.?
Purchased 3 SM5100B boards and two of the dev boards.
I am able to talk to the SM5100B but cannot get it to authenticate with a good T-mobile SIM card to the network.
Yes, I have a good antenna, a good power supply etc.
I am in the US and have the Frequency set for GSM 850.
T-Mobile says that perhaps these devices are “blacklisted” for their network.
Has anyone been able to get these to connect to T-Mobile in the US? If so, what are the settings I need to do this.
No public wish lists :(
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