I'm developing a GPS tracking with two Telit's modules and a Cortex-M4 processor. The module I've been using is a Jupiter JN3 and a GL865 QUAD. I'm not using any development kits, mainly because this is gonna be my graduation presentation.
So here's the deal, I managed the GPS module to work properly, it sends me the NMEA sentences with the frequency I desired, but the GL865 has been showing me a funny behaviour.
I power the module and the power monitor sends me 2.8V, as expected. The RXD and TXD pins, at first, was working fine and responding to my AT commands, which are sent from the processor. Now it stopped working to any of my commands. I put a scope on the RXD and TXD and it shows me almost a square waveform for a few seconds and then both outputs are going low. Sometimes, I turn on the module and these outputs are constantly high.
I've sent a lot of commands trying to make it work and no response. My thoughts are that the module is going to some kind of sleep state, but the wake commands doesn't work too.
I made some measures and it shows me that the VBATT is short-circuited to GND such as the antenna. I think the antenna is fine, there must be some kind of internal high frequency filter, but the VBATT concerns me.
Has anynone experienced the problem, Any ideas? I can send the schematics and the waveform if neede.
Yes, Harold, probably it's broken, but it's really weird. It was working fine and suddenly stopped. I'm trying to find another module to compare with mine and see if the problem is in my PCB, but here in Brazil it's really difficult to find and they're very expensive because of the importation taxes. Anyway, thanks for the help, I'll keep you posted if I find the problem.
Hey Harald, I've got a new module, it's in my pcb and it's working fine (thanks god).. Now I've got a new problem, hope you can help me.
I've configured the module through AT+SGDCONT, AT#GPRS=1, and the I try to establish a connection through AT#SKTD=0,80,www.google.com for example and it returns me an error message: operation not supported.
Thanks in advance.
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