Serial network card open source version

**Related Code** This code, available
at https://github.com/mynewworldyyl/jmicro_stm32
, is ported to STM32. The microcontroller uses this code to connect to the network card for internet access. Other chips can also be ported using this code.

**JMICRO Backend**
Besides supporting general UDP and TCP, this network card further encapsulates the open-source microservice backend project (https://github.com/mynewworldyyl/jmicro) to support remote RPC calls, asynchronous message publishing and subscription. If only UDP or TCP is used, this backend project is not required.

**Network Card and Microcontroller Wiring**
When using the network card, only four wires are needed: 3V3, GND (powering the network card), RX0 of the network card connected to the TX port of the microcontroller, and TX0 connected to the RX port of the microcontroller.
![image.png]
**Network Card Configuration**
Two methods:
Method 1: Directly configure the network in the microcontroller using the following method:
void ICACHE_FLASH_ATTR jm_serial_configWifiPwd(char *ssid, char *pwd);
Method 2: There is a button on the network card. Press it quickly 3 times in a row. The network card will enter AP mode. Connect your computer or mobile phone to the Wi-Fi of this AP (named "JMicro_JXX_Configure Network"). After successful connection, enter 192.168.X.1 (X is usually 4, try starting from 2 if it doesn't work) in your browser to open the following page. Enter the Wi-Fi name and password and submit. If the configuration is incorrect or you need to change the Wi-Fi password, you can repeat the above method to reconfigure.

![Configure Network Webpage.png]
**STM32 Related Notes**
In STM32, the source code uses PA2 and PA3 by default, which is USART2. If you need to use other serial ports, you need to modify the Serial.c source code accordingly.
In STM32, TIM3 is used as the basic time base by default. You can also use other timers, or make sure to call the jm_ElseMs(1) method every millisecond.

**Network Card Programming** This
command-line program requires Python and esptool.py. The relevant bin files are provided in the attached bin.zip file. The output is
: `python "./esptool.py" --port COM6 --baud 115200 write_flash --flash_freq 80m --flash_mode dout --flash_size 4MB 0x0000 "eagle.flash.bin" 0x10000 eagle.irom0text.bin 0x3FB000 blank.bin 0x3FE000 blank.bin 0x3FC000 esp_init_data_default.bin`.

For graphical tool programming, simply refer to the address and corresponding file configuration in the above command.
`0x0000 "eagle.flash.bin" 0x10000 eagle.irom0text.bin 0x3FB000 blank.bin 0x3FE000 blank.bin 0x3FC000` esp_init_data_default.bin

**jm_client API Related Instructions**
Client source code program. A major difference between this network card and other serial network cards on the market is that it provides a complete client API. Whether using TCP, UDP, RPC, or message publish/subscribe, it is very convenient and easy to use. If it is based on JM UDP, the underlying layer has already implemented the assembly and acknowledgment of data packets, ensuring that data packets are accurately and non-repeatedly sent to the other party. The same applies to response data packets.

To send a UDP-based HTTP request, simply call the `jm_udp_sendArray` method: `
char *p = "GET /index.html HTTP/1.1
";
jm_udp_sendArray("192.168.3.4",9092, (uint8_t *)p, jm_strlen(p));`
You can create a web instance on your computer, such as Tomcat, at 192.168.3.4:9092. The microcontroller will return a page or a 404 result, indicating that the UDP connection to the web service has been established, but the page does not exist, hence the 404 page.


**Receiving UDP packets and calling the method**
void _jm_udp_testOnData(const char* host, int port, jm_buf_t *buf){
uint16_t len ​​= jm_buf_readable_len(buf);
for(int i = 0; i data[i+buf->rpos]);
}
}
// Register the method to receive UDP packets
jm_udp_setDataCb(_jm_udp_testOnData);

For complete demo code related to TCP, RPC, and asynchronous messages, please visit the Github project to download the source code.

Currently, the complete TCP and UDP APIs are publicly available. For RPC and message-related APIs, please refer to the jm_client.h header file. The code snippet provided demonstrates
how to send UDP data . uint16_t len); void ICACHE_FLASH_ATTR jm_serial_init(); // Receive UDP datagrams














//void jm_upd_onData(const char* host, int port, jm_buf_t *buf);

//Receive UDP datagrams
void jm_tcp_onData(const char* host, int port, jm_buf_t *buf);

//Receive serial port datagrams
void jm_serial_onData(jm_buf_t *buf);

/**********************************TCP Module Start*********************************************/
//TCP Module Initialization
void ICACHE_FLASH_ATTR jm_tcp_init();

//Method for receiving TCP return data
ICACHE_FLASH_ATTR void jm_tcp_setDataCb(jm_tcp_onData_fn cb);

//TCP connection established, return value greater than 0 indicates success, others indicate failure
BOOL ICACHE_FLASH_ATTR jm_tcp_connect(char *host, uint16_t port);

//Close TCP connection
BOOL `ICACHE_FLASH_ATTR jm_tcp_close(jm_tcp_socket_t sock);

` // TCP data transmission
`sint8_t` `ICACHE_FLASH_ATTR jm_tcp_sendBuf(jm_tcp_socket_t sock, jm_buf_t *buf);

` // TCP data transmission
`sint8_t` `ICACHE_FLASH_ATTR jm_tcp_sendArray(jm_tcp_socket_t sock, uint8_t *data, uint16_t len);

` // Establish TCP connection, `jm_tcp_connect` uses this method to establish the TCP connection
`BOOL ICACHE_FLASH_ATTR jm_serial_tcpconnect(char *host, uint16_t port);

` // Close TCP connection `
BOOL ICACHE_FLASH_ATTR jm_serial_tcpclose(jm_tcp_socket_t sock);

` // Configure Wi-Fi username and password `
void` `ICACHE_FLASH_ATTR jm_serial_configWifiPwd(char *ssid, char *pwd);`

// Checks the connected Wi-Fi name. Note that Chinese characters may cause garbled text, so it's best to avoid using Chinese characters in the Wi-Fi name. `void ICACHE_FLASH_ATTR
jm_serial_getWifiSsid();

` // Checks if the Wi-Fi is available . `BOOL ICACHE_FLASH_ATTR jm_serial_isWifiEnable(); ` // Checks if the network can access the internet. `BOOL ICACHE_FLASH_ATTR jm_serial_isInternetEnable(); ` **Network card button functions:** Press once: No function defined yet, as it's easy to press accidentally. Press twice: Restart the network card. In terminal mode, you can restart the network card to restore its functionality. Press three times: Enter AP configuration mode. See the configuration instructions above. Press four times: Enter Smart configuration mode. Requires JMicro APP support. You can configure the Wi-Fi account and password for the network card even when not connected to Wi-Fi. Press five times: Reset the network card to factory settings . The network card SD card is currently unused. Plans include adding a read/write interface for the SD card or adding a data cache to the network card . [Images: ![WeChat image_20240628122332.jpg] ![WeChat image_20240628122349.jpg]]