4G

This article guides readers on configuring 4G modules on the Edge101 mainboard, explaining the PCIe pinout and providing example code for network time synchronization using an ESP32 controller.

8.8 4G

The Edge101 mainboard comes with a built-in standard 4G CAT1 communication module by default. You only need to install the 4G antenna included in the accessories to enable the 4G communication function.

PCIe pin assignment of the wireless module is as follows:

1	WAKEUP_OUT	2	VCC_3.3
3	U_BOOT	4	GND
5	NC	6	NC
7	NC	8	USIM_VCC
9	GND	10	USIM_DATA
11	VDD_EXT	12	USIM_CLK
13	NC	14	USIM_RST
15	GND	16	NC
17	NC	18	GND
19	WAKEUP_IN	20	NC
21	GND	22	RESET_IN
23	UART_RXD	24	VCC_3.3
25	UART_RTS	26	GND
27	GND	28	UART_CTS
29	GND	30	NC
31	UART_TXD	32	WAKEUP_OUT
33	RESET_IN	34	GND
35	GND	36	USB_DN
37	GND	38	USB_DP
39	VCC_3.3	40	GND
41	VCC_3.3	42	LED_WWAN
43	GND	44	NC
45	NC	46	NC
47	NC	48	NC
49	NC	50	GND
51	NC	52	VCC_3.3

Refer to the above PCIe pin assignment when equipping other wireless modules.

Sample codes for 4G functions are provided for your reference. The relevant library is built into the SDK of this product, which can be found in the example folder.

The following tutorial demonstrates acquiring network time via 4G network connection.

Note: Insert the SIM card before using the 4G function.

Example: Obtain Network Time

Hardware Preparation

ESP32 IoT Programmable Controller (SKU: DFR1283)

Sample Code

#include "DFRobot_EG800AK.h"
#define NTP_SERVER "ntp.aliyun.com"
DFRobot_EG800AK EG800AK;

// Convert UTC time to Beijing Time (UTC+8) and format output as 2026/07/11 16:53:50
String formatBJTime(String raw)
{
  // Sample raw data: 26/07/11,08:53:50+32
  int year  = raw.substring(0,2).toInt();
  int month = raw.substring(3,5).toInt();
  int day   = raw.substring(6,8).toInt();
  int h     = raw.substring(9,11).toInt();
  int m     = raw.substring(12,14).toInt();
  int s     = raw.substring(15,17).toInt();

  // UTC + 8 hours = Beijing Time
  h += 8;
  // Handle date carry when crossing midnight
  if(h >= 24){
    h -= 24;
    day += 1;
  }

  char buf[32];
  sprintf(buf,"20%02d/%02d/%02d %02d:%02d:%02d",year,month,day,h,m,s);
  return String(buf);
}

void setup() {
  Serial.begin(115200);
  while (!Serial);
  EG800AK.begin(Serial1, eBaud115200);
  EG800AK.setBaudRate(eBaud115200);

  if (!EG800AK.checkSIMStatus()) {
    Serial.println("SIM card abnormal");
    while(1);
  }
  Serial.println("SIM card normal");

  EG800AK.activePDPContext();
  EG800AK.setNtpRetransParam(5,10);
  EG800AK.openNtpSynchronization(NTP_SERVER);
  delay(3000); // Extend waiting time to complete the initial NTP synchronization
  Serial.println("Start reading Beijing Time");
}

void loop() {
  char *timeStr = EG800AK.getCLK();
  if(timeStr != NULL){
    Serial.println(formatBJTime(String(timeStr)));
  }
  delay(2000);
}

Result

The real-time Beijing time is successfully obtained via the 4G network.