ADIY 4G LTE modem with SIM card socket, SMA antenna connector, DC power jack, and an RS232 interface supports wireless communication modes of LTE-TDD/LTE-FDD/GSM/GPRS/EDGE.
This board is built around the SIMCOM A7670C LTE module and comes with an RS232 interface. The RS232 interface enables easy connection with the computer or laptop using a USB to Serial connector or to the microcontroller using an RS232 to TTL converter. A 3-pin header also exposes a 1.8V level UART interface for direct interfacing with microcontrollers. Communication with A7670C is done using AT commands.
Technical Specifications:
- Suitable for LTE and GSM networks.
- DC Jack input voltage: 9-12V
- frequency bands supports LTE-FDD, LTE-TDD, and GSM.
- Control via AT commands.
- In-built SIM Card Holder.
- Power LED and Network Status LED.
- Powerful TCP/IP protocol stack for internet data transfer.
- Supports maximum 10Mbps downlink rate and 5Mbps uplink rate.
- Abundant software functions: USB
- RS232 DB9 Connector interface.
- SMA connector for external antenna.
- 1.8V UART header.
- Recommended Sim card: JIO 4G Sim
Jagdish Lovenshi –
Hello
am currently working on a project involving the integration of an ADIY 4G LTE Modem (A7670C) with Arduino. I’ve encountered an issue with the initialization process, and after some investigation, I discovered that the A7679C module has a 1.8V UART header.
To address this, I purchased an I2C Bi-Directional Logic Level Converter (4 Channel) from Robu, successfully shifting the voltage from 1.8V to 5V. However, even with the level shifter in place, the program is still stuck at the initializing stage.
Additionally, I observed an interesting voltage behavior when testing the 4G module’s RX and TX directly without the level shifter. The RX voltage is reading 3V, while the TX voltage is 1.8V when measured with a multimeter. I’m uncertain whether these voltage readings are normal or if there might be an abnormality causing the initialization issue.
I have tried various baud rates ranging from 9600 to 115200 without success. I would greatly appreciate any insights or suggestions from the community regarding this problem. Has anyone encountered a similar issue with the A7670C module, or does anyone have recommendations on troubleshooting steps I can take to resolve the initialization problem?
Thank you in advance for your time and assistance.
code
#include
//Create a software serial object to communicate with SIM800L
SoftwareSerial mySerial(3, 2); //SIm Tx & Rx is connected to Arduino #3 & #2
void setup()
{
Serial.begin(9600);
mySerial.begin(9600);
Serial.println(“Initializing…”);
delay(1000);
mySerial.println(“AT”); //Once the handshake test is successful, it will back to OK
updateSerial();
mySerial.println(“AT+CMGF=1”); // Configuring TEXT mode
updateSerial();
mySerial.write(26);
}
void loop()
{
while (Serial.available())
{
mySerial.write(Serial.read());
}
while (mySerial.available())
{
Serial.write(mySerial.read());
}
}
void updateSerial()
{
delay(500);
while (Serial.available())
{
mySerial.write(Serial.read());//Forward what Serial received to Software Serial Port
}
while(mySerial.available())
{
Serial.write(mySerial.read());//Forward what Software Serial received to Serial Port
}
}