- Tue Mar 22, 2005 4:17 pm
#3699
Forgive me for turning this into a personal blog - but get set:
The Telit GM862 PCS is a great little device. The additional Agilent ADCM2650 camera is a cool little add on as well.
We've been trying to get the interface working for quite some time. Because of limitations with the datasheet, limited support, and an absolutely $%#^ed example schematic (GM862 hardware description page 60) - the camera has not worked. Until now!
A picture of my desk:
The new GM862 eval boards (GM862 EVK v1b) should be available April 5th, 2005.
What where the problems you ask?
1) Online photos and datasheets of the agilent camera have the white dot (pin 1 indictor) located on the right side. These cameras are shown with a thicker ribbon. The camera modules that Telit sent use have a much thinner ribbon (http://www.sparkfun.com/images/Cellular ... mera-0.jpg) with the pin 1 indicator on the opposite side. The pin1 on the left side is correct.
2) The schematic on page 60 of the GM862 hardware datasheet is reversed. Pin 1 on the camera is GND, pin 2 is MCLK, pin 17 is VCC (2.8V).
3) Page 44 of the GM862 hardware datasheet describes pin 50 of the GM862 being connected to pin 2 of the camera (VCC Main of 2.8V). Well this is truly screwy. VCC is actually pin 17 on the cameras being shipped. Furthermore, the GM862 pin 50 cannot source enough current to power the camera directly - so you must connect pin 50 to the enable pin of a 2.8V regulator as shown in the schematic on page 60 (remember the one with reversed pins?).
So we have all sorts of reversed descriptions and pin outs. I imagine it's really Agilent's fault for changing the camera design. But Telit should have noted *all* of these changes and updated the datasheets accordingly.
Finally is my beef with Round Solutions Support Forum - the support forum linked to from the official www.gm862.com website. They look like they are the technical support from Telit. Really it's just a guy named Harald and a batch of other users. Much like SFE and Olimex, Harald runs Round Solutions and sells Dev boards specifically for the GM862. He's not Telit. And he repeatedly tries to sell his dev boards onto users who report problems with the Telit device or datasheets - rather than trying to help them : http://www.modem-gsm.de/forum/showthread.php?id=1135
I am glad the Round solutions support forum is at least there. We were able to diagnose a few problems we were having. However, when I posted a topic last night describing the new VB script that I created to download a picture from the GM862 module, the topic was deleted by morning. I had to develop the program because the test software by roundsolutions/telit simply corrupts the image during every download. Harald can't stand the heat.
Ahh. I feel better.
The SFE Take Photo VB program including the VB source is available here : http://www.sparkfun.com/tutorial/GM862-TakePhoto.zip. We wanted to share a decent example of how to control the GM862 using AT commands as well as fixing the download glitch found in the Round Solutions test program.
-Nathan
The Telit GM862 PCS is a great little device. The additional Agilent ADCM2650 camera is a cool little add on as well.
We've been trying to get the interface working for quite some time. Because of limitations with the datasheet, limited support, and an absolutely $%#^ed example schematic (GM862 hardware description page 60) - the camera has not worked. Until now!
A picture of my desk:
The new GM862 eval boards (GM862 EVK v1b) should be available April 5th, 2005.
What where the problems you ask?
1) Online photos and datasheets of the agilent camera have the white dot (pin 1 indictor) located on the right side. These cameras are shown with a thicker ribbon. The camera modules that Telit sent use have a much thinner ribbon (http://www.sparkfun.com/images/Cellular ... mera-0.jpg) with the pin 1 indicator on the opposite side. The pin1 on the left side is correct.
2) The schematic on page 60 of the GM862 hardware datasheet is reversed. Pin 1 on the camera is GND, pin 2 is MCLK, pin 17 is VCC (2.8V).
3) Page 44 of the GM862 hardware datasheet describes pin 50 of the GM862 being connected to pin 2 of the camera (VCC Main of 2.8V). Well this is truly screwy. VCC is actually pin 17 on the cameras being shipped. Furthermore, the GM862 pin 50 cannot source enough current to power the camera directly - so you must connect pin 50 to the enable pin of a 2.8V regulator as shown in the schematic on page 60 (remember the one with reversed pins?).
So we have all sorts of reversed descriptions and pin outs. I imagine it's really Agilent's fault for changing the camera design. But Telit should have noted *all* of these changes and updated the datasheets accordingly.
Finally is my beef with Round Solutions Support Forum - the support forum linked to from the official www.gm862.com website. They look like they are the technical support from Telit. Really it's just a guy named Harald and a batch of other users. Much like SFE and Olimex, Harald runs Round Solutions and sells Dev boards specifically for the GM862. He's not Telit. And he repeatedly tries to sell his dev boards onto users who report problems with the Telit device or datasheets - rather than trying to help them : http://www.modem-gsm.de/forum/showthread.php?id=1135
I am glad the Round solutions support forum is at least there. We were able to diagnose a few problems we were having. However, when I posted a topic last night describing the new VB script that I created to download a picture from the GM862 module, the topic was deleted by morning. I had to develop the program because the test software by roundsolutions/telit simply corrupts the image during every download. Harald can't stand the heat.
Ahh. I feel better.
The SFE Take Photo VB program including the VB source is available here : http://www.sparkfun.com/tutorial/GM862-TakePhoto.zip. We wanted to share a decent example of how to control the GM862 using AT commands as well as fixing the download glitch found in the Round Solutions test program.
-Nathan