Hi,
I have purchased a SIM5320E module from ebay (I bought the cheapest one I could find as of 6 weeks ago). I notice there are even cheaper breakout board there now for 30% less price.
Problem 1
When I connect power to the board (From a 5v power supply, not the arduino 5v pin), the onboard leds flash on and off. They stay on for 7 seconds and then off for 4 seconds, this is repeated forever regardless if the arduino is powered on or not.
On some odd occasions the leds just stay on.
I can't find any info on what the led blinking indicates.
My multi meter indicates that when the leds are on or off it's taking between 50ma to 100ma at 5v.
I've found the problem and wanted to share it here in case anyone else is having the same issues.
Fix to problem 1:
Capacitor solder joints are broken - See attached image
If I push this capacitor down it rejoins the broken connection. The leds now stay solid/lit up all the time. This explains why, on the odd occasion, I was getting the leds to stay on - I'm working on my bed and hence any movements by me move the board a little bit.
Problem 2
Now I have the leds staying on. But I still wasn't able to send an sms.
This is because there was no network connection. The network connection led is supposed to blink on off roughly every second to indicate that there is signal.
I thought the problem may be the aerial, the supplied aerial looks like the cheapest available, not that I was surprised.
I tried another aerial that I had and 2 seconds of connecting this aerial, the network light started flashing as though there was signal, and my sms made it through. Nice!
And then the network light stopped blinking 10 seconds later and the sms's weren't going through either.
I tried swapping the aerial cables over a few times, sometimes the network light blinked and other times it didn't, regardless of the aerial.
I've found the problem for this, too.
Fix to problem 2:
Bad aerial connection - See attached image
If I put pressure on the connection, the network light stays blinking. If I take pressure off the connection, sometimes the network light keeps blinking, other times it turns constantly on.
Hopefully this helps if anyone is having the same issues.
This is the second item in a row that I've bought from ebay that has had problems, both of these items being rather expensive compared to 'typical' arduino products.
Over the past year I've purchased plenty of cheap sensors and arduino boards, and haven't had any significant problems. These more expensive products seem to be a different story or I've just had a run of bad luck!
EDIT: I'm also not sure why this product comes with masking tape over the SIM5320E chip?
