Hi, I’m trying to connect EC20 mini pcie module with MCU STM32F103 via uart interface. I’m getting problem with EC20 module, it not respond anything when I send AT command. When I plug power supply I can see led wwan status toggle normal and I can call to module. I tested EC20 module with USB interface, it working normal.
Pls help me fix this problem !
Dear Linh Bui,
Thanks for your inquiry in Quectel forum.
About your issue, could you help to confirm the following information:
1.whether you use the correct board to connect EC20 MINIPCIE module;
2.please know that EC20 is used in China marketing, normally it named EC20 minipcie-c module, you can see the label in the bottom of the module.
3. Please confirm the UART level is matched between module and your MCU.
Hi Kyson,
My EC20 module: EC20CEHCLG-128-SNNS
All module pin correctly, power supply 3.3V
UART interface level 3V3 ??? .
I read in file Quectel_EC20_Mini_PCIe_Hardware_Design_V1.1, it show UART level 3V3, but measurement by ossilocope and DMM it show only 1V8. I think that problem.
Pls confirm it correct !
Please check the following difference between MINIPCIE and MINIPCIE-C module, they have different UART power domain. Please note that EC20 module is apply for China domestic marketing, they are all MINIPCIE-C module, you can check the label at the bottom of the module. So i think you may use MINIPCIE-C module, not MINIPCIE module. Please check it. Thanks!
Please check the following document. Thanks!
Quectel_EC20_R2.1_Mini_PCIe-C(Audio)_Hardware_Design_V1.0.pdf (835.5 KB)
Hi Keyson,
Thank you very much for your time and your guidance.