Solder bridge on network socket

☎️ Ringo (MAKERphone)
#22

Ok, then just let’s say that the 4G module may or may not be able to drive the speaker without an amplifier, while the 2G module never needs an amplifier. That is difference #1.

In addition, I see a 1.5K resistor to GND from pin 2 of U1.1 (level converter) on the 4G board that is not on the 2G board. This is part of the serial interface between the brain board and the network module. I don’t know what function DTR plays here or why it needs to be pulled down for 4G only. This is difference #2.

That’s all that I could see, but then my eyes aren’t what they used to be.

Not Calling Or Connecting To Network?
#23

@frankprindle

You’re right, those are the only two differences

DTR is used for putting the network modules to sleep

SIM7600 has some special mumbo jumbo that requires it to have that resistor on DTR.

The amplifier difference is because SIM800 has the amplifier built-in whilst SIM7600 doesn’t have one. We just couldn’t make both modules work with the external amplifier and were running low on time so we’ve just branched the boards