I can use my Universal Communication Adapter to code most of what is on this card, so I am in no hurry to order this PCB. The fact is I miss package sizes, so I just need to sit & wait a little for now. I am however running out of space in front, so I am considering increasing the size from 65mm to 75 or even larger. I am going to draft some of the other PCB’s to make up my mind.
I dropped sound support on this and I am a bit disappointed with the need for a 4V/2A PSU that require some extra space. This makes the GSM module much larger than you expect it to be. One nice thing about this PSU is however the digital on/off pin enabling me to switch off GSM power completely. I am drafting with SIM800C to get experience, but I have not decided what module to use yet. It is sometimes very difficult to choose without experience so you see what the differences mean.
I selected SIM800C over M590E due to sound support, but as I realize that sound is analogue only I need to look into the other (and maybe far more expensive) modules for digital sound support. The issue here is that using am ADC/DAC is possible, but as the sound is digital inside the GSM module I would rather swap to a module that offer sound IO on digital packets to avoid the extra noise. I need to work on this a little – nothing is settled yet.
I am also considering moving the GSM module to the top to let the antenna be on “top”. to avoid that it is in the way of Ethernet/Wifi.
Also, the difference between this and the All-In-One Home Central is very small at present…