I'm having a problem. Once I got the board working using the power and usb connections, I began to eliminate pieces of the evaluation board with the goal to ultimately run tx/rx through an arduino. Using the test schematic for the ADH8066 Breakout Board, I've been able to replace the usb with a FTDI Basic board connected to TX, RX, & ground. (DSR & DTR jumpered).

For this configuration, I've been able to have the board boot successfully by powering the board (using the power jack on the evaluation board), then holding the ONKEY button for a couple of seconds. The green Network LED then goes out, and after 5-10 seconds, lights up again. At this point the board is functional.

My problem is when I try to power the GSM module through an external Vbat. I'm powering the module using a 4V regulated supply connected to VCC. When I do this (at this point neither the power or the USB connectors onboard are being used), a) Command and Network LEDs light upon powerup, b) Network light turns off with ONKEY button, and then c) the network LED never re-lights, and the module appears to be off/not listening.

Am I doing something wrong, or is there a reason why this cannot be done using the evalutation board? Thanks in advance for any help you can provide.

I believe there is an error with the board. Pin 3 (RTS#) of the FT232RL (Output) is connected to pin 37 (RTS0) of the ADH8066 (also an Output). Shouldn't it be like this:
FTDI 11 (CTS#) to ADH 37 (RTS0)
FTDI 3 (RTS#) to ADH 34 (CTS0)
And I think
FTDI 2 (DTR#) to ADH 35 (DSR0)
Has anyone gotten hardware flow control to work on this board? Honestly the data sheet is terrible. I am considering a different module.

Firmware update link is down?
Working wonderfully with external power :-)

Do other people see the datasheet as garbled? The pinout is totally illegible (multiple lines of text overlapping etc). I can't find a datasheet on the manufacturer's website either. SFE, do you have a better copy?

In order to use the TX/RX pins instead of the USB, do I need to de-solder the solder jumpers?

Is there any specific reason why the DSR0 pin is pulled low on the board?

Make sure you have your terminal program append each command with CR or CRLF otherwise the device wont respond to the command.
This drove me nuts for about an hour and then I saw AT reference a command postfixed with CR. I had my terminal appending LF. I changed it and problem solved!

Comment Removed

The design of the LED drivers for the "Command Ready" and "Network Ready" indicators is wrong on this board and the status LEDs do not work as expected. I confirmed this with the manufacturer, ADH. Adding a 1K resistor from the base connection of each driver transistor to GND will solve the problem, and the status indicators will work as expected.

RobertC.:

Are you checking page 2 of the schematic?
Of course! Sparkfun has updated the files to include the 2nd page in both the .pdf and the Eagle .sch files. They tried to pull the old "didn't you look at page 2" also, but I had my earlier downloads archived! You've got to get up earlier in the afternoon than that to fool me! After all, I work for a company that routinely releases new code to fix bugs WITHOUT upping the version number, and then says "what bug" to our customers......

The .pdf schematic has been updated now to include the missing 2nd page, so all is good! Also, the .Eagle .sch file now includes the 2nd page as well! Thanks, Sparkfun!

FYI, to get this working in Windows, plug it in, launch a terminal and point it to the correct COM port, baud rate 115200, flowcontrol = none
When powering up the module, you should see "READY". Using it was a little finicky at first; had to plug it in, open the serial connection, put the SIM card in, turn the unit on, start sending commands. If the SIM was in before plugging the unit into the computer, I was not able to send commands.
After that, it's just normal AT commands. BTW, this works with Telit's RS Terminal software (which is just sending AT commands anyway).