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1  Products / Arduino GSM Shield / Re: Powering the GSM shield when not "shielded" on: September 26, 2013, 02:22:22 am
The design goal was to reduce the amount of current needed through the use of the huge capacitor.
Usually, the duration of 2A peak is in the us range but it is enough to cause a reset event. The capacitor tries to hold the voltage when this happens provided that the input current is not too low. I think the recommended 700-1000 mA should be enough.

When selecting battery, take a look at the maximum pulse current capability.
For example, I used a wrongly battery of Li Thionyl with 250 mA pulse current only.
The board didn't work and resets all the time. Then, I swapped to one rated for 2000 mA, then it work.
2  Products / Arduino GSM Shield / Re: Powering the GSM shield when not "shielded" on: September 25, 2013, 08:29:02 pm
It sure look like a power issue. Registering to the network will surely eat more current.
At least your 2nd setup should work. Probably some wiring mistake?

I doubt the 9V battery will do any good. Check the maximum current that can be delivered like for example the battery here:
3  Products / Arduino GSM Shield / Re: Powering the GSM shield when not "shielded" on: September 24, 2013, 03:15:31 am
I was using something like that back then, it didn't work. That is around AWG28 I guess. Pretty thin wires.
4  Products / Arduino GSM Shield / Re: Powering the GSM shield when not "shielded" on: September 23, 2013, 10:17:56 am
What gauge size is your jumper wires?
Not all wires can carry that much of current.
5  Products / Arduino GSM Shield / Re: SIM900d + Atmega328 Sending SMS(having problem with digital input pins) PLS HELP on: September 01, 2013, 02:17:30 am
Your pins are floating I guess.
You don't have any pull down resistor to set it's default state as low (as you wanted high level to trigger an event)?
6  Using Arduino / Networking, Protocols, and Devices / Re: u blox neo-6m and arduino uno problem on: August 21, 2013, 09:59:16 am
I think most uBlox GPS comes default at 9600 bps instead of 4800 bps like the rest.
I used both MAX-6Q and NEO-6M, both work at 9600 bps out of the box.
7  Products / Arduino GSM Shield / Re: Trouble attaching GPRS (hangs) on: August 18, 2013, 09:47:56 pm
Although I'm not using this shield particularly, when I wrote the library to support my own product based on other chip, I would have a timeout and several times retry mechanism in the GPRS attaching method. Some times, the base station will not have enough allocation for GPRS slots as voice calls gets higher priority. And yes, the delay won't work in all cases. Just try moving from different service provider, and you'll notice it won't work for all cases with the delay approach.
8  Development / Other Hardware Development / Re: Need Arduino proto-shield as Protel, P-CAD, OrCAD, PADS, AutoCAD on: August 15, 2013, 09:32:18 pm
Diptrace can import Eagle using an ULP script.
And from Diptrace format, you can export to PCAD and Orcad.
9  Using Arduino / Networking, Protocols, and Devices / Re: FT232RL Failure on: August 07, 2013, 04:16:04 am
Where did you get your FTDI chips supply from?
I guess FTDI only interested to support you if you are buying from them or through one of their official distributor.
10  Community / Products and Services / Re: MCP79412 Real-Time Clock/Calendar breakout board on: July 25, 2013, 05:52:05 am
Library looks very well written and much effort put in!
11  Community / Products and Services / Re: Cheap laser cut aluminum frame PCB stencil service on: July 25, 2013, 05:48:39 am
I'm having a little trouble imaging how to ensure aligment of a 10cm x 10cm (or smaller) board inside the very much larger frame area.
You save money by combining several boards or design into 1 stencil.
It's more accurate then the Mylar/Kapton stencil and with the price like these, there's no reason not to.
I have used the smaller 30cmx40cm and manage to put in 4 design for prototypes.
12  Products / Arduino GSM Shield / Re: GPRS connection problem on: July 24, 2013, 05:36:19 am
This is quite true for most GSM module.
Once registered to the network, you definitely need to give the module a breather before trying to hook o the GPRS.
13  Development / Other Hardware Development / Re: Designing shields with multi-board compatibility in mind? on: June 02, 2013, 09:13:54 pm
Designing shields compatible with various boards is hard but can be done.
Other than the operating voltage differences, pins assignment are probably one of the more important things to look at.
For example, the external interrupt pin on Leonardo is on D0-D3 and on an Uno is on D2 & D3. At the same time, I2C pins are also on the Leonardo's D2 & D3. You also have to consider library compatibility for each pins. Like for example, only certain pins can be used to act as RX pin using the software serial library.
14  Using Arduino / Networking, Protocols, and Devices / Re: FT230XS as cheap replacement to FT232RL? on: May 10, 2013, 09:54:56 pm
I'm currently using FT231XS (instead of FT230XS) on a selling product and it works great. The pins (including the TXD & RXD) are 5V  tolerant, an FTDI engineer clarified this to me. You don't have to worry on the USB VID & PID by using the FT-X series! And it's still cheap even after combining them with the ATMega328!
15  Using Arduino / Networking, Protocols, and Devices / Re: GPRS SHIELD EMAIL attachment problem on: March 11, 2013, 10:51:10 pm
I'm afraid your only option is to run the sketch with the Serial monitor open, capture the data, and replicate the session by connecting to your smtp server using a network terminal (port 25).
This is the best way to learn whether your syntax is wrong or right.

The code never checks the server's response, so there's no way to see which error messages, if any, are sent back by the server.
The Serial.find() function call can be used to check whether expected positive result is received from the server.

But, like spatula mentioned earlier, try replicating the session, so you know what to expect from the server.
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