Testing EC200U-CN in PCB

Technical Subjects
1

I want to test EC200U-CN with Qnavigator application. I have attached 2 test points RX and TX with TTL module with port5 by UART. I am connecting with module but it’s getting error with sync up with quectel. I don’t understand the issue. EC200 is in the vehicle tracker device. that means it’s not alone but combined with PCB. if any had try please help.

2

Could you please provide the photos of the current test scenario?

3

Capture_8945959474309621446
Capture_89459594743096214461920×2560 321 KB

I am testing from test points of EC200-CN RX and Tx points which is TP12 : main RX and connected with TTL module TX and TP13 : main TX and connected with TTL module RX. as in image two blue wires are attached. I am giving power supply to PCB. TP12 is getting 3.2v and TP13 is getting 1.8 v.
TTL port is port5 with UART. but application is getting this errors :
/* Start AT SYNC: Send AT every 500ms, if receive OK, SYNC success, if no OK return after sending AT 10 times, SYNC fail */
[2025-09-29 15:37:19:239_S:] AT
[2025-09-29 15:37:19:752_S:] AT
[2025-09-29 15:37:20:267_S:] AT
[2025-09-29 15:37:20:783_S:] AT
[2025-09-29 15:37:21:300_S:] AT
[2025-09-29 15:37:21:816_S:] AT
[2025-09-29 15:37:22:329_S:] AT
[2025-09-29 15:37:22:846_S:] AT
[2025-09-29 15:37:23:360_S:] AT
[2025-09-29 15:37:23:878_S:] AT

/* No OK return after 10 times, will pop out error message of SYNC fail, you may check below settings are correct and then connect to module again:
1.the module power on normally
2.serial port cable is connected
3.the baudrate in serial port parameter set is the same with module */

4
  1. Please measure whether the VDD_EXT pin is 1.8V.
  2. Is PWRKEY enabled?
5

I have the same problem with the ec200 and rg255 modems that I bought in China, I don’t have that problem with the ec200 modem that I bought in Europe.

6

If you purchase the EC200UEU in Europe, its TXD/RXD connections will be opposite to those of the EC200UCN.

7

image1
image11366×720 94.8 KB

here :
In signal level gps - 5 total, 3 active , 2 deactive satellites

In sky view - 13 gps

logs :
$GPGSV,4,1,16,31,80,197,31,28,64,039,02,48,273,10,37,105,29,161
$GPGSV,4,2,16,199,33,050,01,32,308,32,31,043,26,28,153,33,157
$GPGSV,4,3,16,04,10,269,25,09,056,03,09,317,194,06,094,28,153
$GPGSV,4,4,16,16,05,182,27,03,200,08,03,229,23,01,124,31,169
I think 16 is total satellites number are there in sentences

so i am getting confused between all different informations