I can positively attribute the effect to my UART handling, as two identical systems with two different Cells are behaving identically. But where is my fault?
I missed this comment - so you're saying you're seeing the same effect on two CELLv1.0s with the same code when you're manipulating the baud rate? That's good that it's consistent actually... means your HW is good.
Miq1 wrote:Thanks for the advice. I already tested with AR and/or AWM set to GND unfortunately with no different results. Remains the check of the info lines; I will need a multimeter or osc to check tomorrow, as the Cell is on a PCB already and not easily rewired.
Great debug steps... so it's not sleeping. It's getting caught somewhere in the switchover.
Have you setup a simple echo device - write from the Arduino IDE through Serial0, print to CELLv1.0, echo results to Serial1? I'm not sure about your code, but getting consistency on an earlier, simple codebase and moving up from there is the way to go.
Debugging when dealing with the rest of the code is a bit of a pain as you don't really know where the error came into play. I would suggest loading this simple echo test and getting consistency on it before moving forward.
Miq1 wrote:I can confirm the odd "send ATE1 9-12 times on 19200, then switch to 38400" method works almost every time I try it. So the Cell seems to be listening in general, but I somehow do not get the data right.
I'm a little confused by this statement... you said it works almost every time. So what is the problem then? Not getting the "OK" after switching the baud?
I'd suggest not switching the baud as a quick test/fix... you're not going to be able to utilize the additional baud rate on an Arduino anyhow. And if your program runs fine without switching, that could point to a clock inconsistency/offset between the two devices. Depending on what clock sources both devices are using, different baud rates act and line up differently with eachother.