Quectel EG-25-G No signal but sim card works in phone

Projects Programming
1

Hello, I have a Pi Pico 4G kit My friend got from someplace online. I put my USA AT&T sim card in there and tried all the commands. I could not get a signal from the modem. The sim card works in my phone I can make calls, text and internet. But in the Quectel modem I can not do anything. It keeps telling me no signal and I'm very close to a window to where I do have great signal.

Not sure what to do and I really need help. I'm attaching my code below just incase. Please someone help me?

This is what I'm getting. AT+CSQ +CSQ: 24,99 OK in google it showing as no signal. Even If It do ATD then a number saying no carrier.

// Raspberry Pi Pico UART ↔ USB Serial Bridge for EG25-G

#define MODEM Serial1   // UART to EG25-G
#define DEBUG Serial    // USB Serial to PC

void setup() {
  DEBUG.begin(115200);
  delay(2000);

  // Initialize UART to modem
  MODEM.setTX(0);  // GP0
  MODEM.setRX(1);  // GP1
  MODEM.begin(115200);

  DEBUG.println("Pico ↔ EG25-G AT Bridge Ready");
  DEBUG.println("Type AT commands below:");
}

void loop() {
  // PC → Modem
  if (DEBUG.available()) {
    char c = DEBUG.read();
    MODEM.write(c);
  }

  // Modem → PC
  if (MODEM.available()) {
    char c = MODEM.read();
    DEBUG.write(c);
  }
}

Joseph

2

Just an update. The carrier I have is AT&T prepaid. Quectel said it should work. I think it might be somewhere the config is not correct. I try to google it and got over 10 ways to do it. A little confusing.

3

how do you power the board?

5

@horace the board side with the Quectel on it has a 5v and 5a power supply and I have the pico plugged into the computer.

Edit: Now I'm wondering if the modem and antenna's are weaker then cellphone a modem and antenna's.