GPS tracker AT - No response

[Arrow008]

Arrow008

1m

post #1

Hello

Trying. to. build. a. GPS tracker

problem: AT commands. no. response on serial monitor. it. looks like. a. micro. controller. try’s to. communicate. to sim7600. but. Sim doesn’t. respond i. tired. to. check. upon. sim on 2. different. computers. mac. and. pc - on. pc. drivers. installed. plugged. in. directly( just. sim7600 ). into. computer. and. and. AT. commands. were responsive (ok) when wired. entire. circuit sim was not. connected. to. computer just wired. to. a. circuit
( stand. alone). couldn’t execute AT. commands. Sim 7600. needs. adapter and i. suspect. problem has. to. do. with. adapter either. faulty. or. not. compatible diagram attached

Gear:

XIAO esp32 c6

Sim7600g-h & adapter ( photo)

Lipo. battery. chargerTP4056

Buck. converter

Motion Sensor SW 420.

wiring ( diagram attached)

battery. charger (3 y splits) TP405 6. out. i>>–> into lipo. and. buck. converter ( y split)

buck.converter(3 y splits) out. i>>–> into Sim7600

buck.k converter out. i>>–> into XIAO esp32 c6

buck. converter out. i>>–> into Motion sensor SW 420

XIAO esp32

D6 ( IX) out. >>–> into SIM. 7600 (RX)

D7 (RX) out.>>–> into. SIM 7600 (TX)

D3 Motion Sensor SW 420

code. for AT commands

Gound. for Sim7600. comes. from XIAO GND ( some. source says it. has. to. . done. like so)

code

#include <HardwareSerial.h>

// Use UART 1
HardwareSerial sim7600(1);

// Raw physical ESP32-C6 pins for the XIAO
const int RX_PIN = 17; // This is the pad labeled "D7"
const int TX_PIN = 16; // This is the pad labeled "D6"

void setup() {
  Serial.begin(115200);
  
  // The LED will blink, then stop here.
  // It waits for you to open the Serial Monitor.
  while(!Serial) { delay(10); } 
  
  Serial.println("=================================");
  Serial.println("Direct Pin Routing Test Started");
  Serial.println("=================================");
  
  // Force the ESP32 to route UART to pins 17 and 16
  sim7600.begin(115200, SERIAL_8N1, RX_PIN, TX_PIN); 
}

void loop() {
  Serial.println("\nSending AT...");
  sim7600.println("AT");
  delay(1000);
  
  // Read any response from the SIM
  while (sim7600.available()) {
    Serial.write(sim7600.read());
  }
  
  // Give you a chance to type AT manually
  if (Serial.available()) {
    sim7600.write(Serial.read());
  }
  
  delay(2000);
}

#include <HardwareSerial.h>

// Use UART 1
HardwareSerial sim7600(1);

// Raw physical ESP32-C6 pins for the XIAO
const int RX_PIN = 17; // This is the pad labeled "D7"
const int TX_PIN = 16; // This is the pad labeled "D6"

void setup() {
Serial.begin(115200);

// The LED will blink, then stop here.
// It waits for you to open the Serial Monitor.
while(!Serial) { delay(10); }

Serial.println("=================================");
Serial.println("Direct Pin Routing Test Started");
Serial.println("=================================");

// Force the ESP32 to route UART to pins 17 and 16
sim7600.begin(115200, SERIAL_8N1, RX_PIN, TX_PIN);
}

void loop() {
Serial.println("\nSending AT...");
sim7600.println("AT");
delay(1000);

// Read any response from the SIM
while (sim7600.available()) {
Serial.write(sim7600.read());
}

// Give you a chance to type AT manually
if (Serial.available()) {
sim7600.write(Serial.read());
}

delay(2000);
}

Thank. you. for. your. help

[xfpd]

You need to clean up your soldering to ensure no burns, shorts or opens.

[van_der_decken]

Something's fishy here...

D+ D- ? As in the USB data lines from the USB connector?

@Arrow008

#include <HardwareSerial.h>

// Use UART 1
HardwareSerial sim7600(1);

// Raw physical ESP32-C6 pins for the XIAO
const int RX_PIN = 17; // This is the pad labeled "D7"
const int TX_PIN = 16; // This is the pad labeled "D6"

And you're connecting them up to a UART?

You know that won't work, right?

[Arrow008]

I was suspecting..so which adapter is compatible ? How should i name it on google or Amazon search?

[van_der_decken]

If the only interface your GPS has is USB, you're going to need a USB host to talk to. Maybe the ESP32 can do that, I don't know; I find the whole ESP32+Arduino experience to be something of a dog's breakfast and avoid it wherever possible.

[TwirlyWhirly555]

Just my two cents but as pointed out USB and UART on the module are two separate interfaces, UART is also only 1.8V compatible ( most breakouts level shift this to 3.3V ) and if you want to use this with UART you need to use that interface.

You need to look for a breakout that has UART as one of the interfaces and is made for the SIM module, Yours looks to be the MiniPCIe style connector with a quick look seems there isn't that many carriers for this ; It might be worth seeing if you can find a cheap full module that has the UART broken out for you if that is the main use goal.

SIM7600G H R2 Breakout Board,Mini SIM7600G-H CAT4 Kits,SIM7600G-H Module Board...

Something Like this has USB and UART that is setup to be 3.3V compatible, Power to the board is 5V

For what its worth I have just done a build with a custom PCB to hold the sim7600 M.2 Module based on the RP2040 ( sits under the SIM module ) UART is level shifted to 3.3V from the 1.8V so there is no reason to not get it running over UART once you have a board that breaks that out.