Hi, I have Quectel_UMTS & LTE_EVB KIT, and I want to connect with a MCU PIC18 (3v3 supply),
In the following image you can see that there are some interfaces that pass the voltages from 1.8 to 3.0 v:
Looking at these diagrams, I distrusted the 3.0 V of the quectel manual, and measured the Vccb pin (19) from U403 Ic, and it is at 3.21 V, I don’t really know if it is at 3.0 or 3.3v.
Does anyone know if there is any test pin where I can go by TTL to the UART of my IC at 3.3V level supply? Tanks.