the result with bench power supply (5.2V and current limit =5A) and with or without the battery (Samsung Li-ion, fully charged, 4.3V) is the same as before. Battery is soldered onto the board where there were no headers populated. Wires soldered onto the top of the gold connections of the battery.
It can still see the SIM:
AT+cpin? => +CPIN:READY
The signal strength is rubbish / doesn’t exist
AT+CSQ => +CSQ: 0,0
I discovered a function for the CSQ which shows what to expect from the result.
AT+CSQ=? => +CSQ: (0-31,99),(0-7,99)
There is a write up on it here:
AT+CSQ – Signal quality | M2MSupport.net
The network status still shows it looking but not finding. I guess no suprise since there is no signal strength
AT+CREG? => +CREG: 1,2
I did notice that at about 10mins after powering it up it volunteered the message:
+CIEV: “Complete the Charge”,100%
AT+CREG=2 => OK
AT+CREG? => +CREG: 2,2,“0000”,“0000”
When I reset I get this:
at+rst=1 => OK
A bit less than a minute later I get a:
I thought perhaps where I was doing this had poor mobile reception so I moved until I had 3/4 bars on my phone. I found a page on my Samsung phone which shows the signal strength as varying between -94 dBm and -98dBm 42 asu (this is with 3/4 bars). Still made no difference.
I wondered if I had mashed the connector for the antenna when putting it on. It is a tough little thing for something so small, but it looks ok under 10x magnification after pulling it off. put it back on and moved it around. No difference.
When I powered it up with the bench supply and no battery (5V from USB UART disconnected, except 0V ref) it was drawing about 50-70mA. When I turn on the GPS it jumps up to 100-110mA or so.
When I connected the battery and bench supply, the bench supply draw was 0 or close to it. As the evening / morning is dragging on the current draw is increasing to 30-40mA. I suspect with the battery coming off its full charge high of 4.3V.
I haven’t seen anything like the suggested 3A of draw, unless it is too quick for my supply display refresh rate or it is not talking to the GSM network properly.
The only thing it seems to do successfully is waste my time… ;-(.
Any other ideas?
Has any one tried this module with a garden variety OPTUS prepaid SIM and got it to work?