_2_APP_C2D_manual.md

iothub_ll_c2d_sample application

• 1. Prepare IoT Hub and Device for this example
  • 1.1. Azure portal
  • 1.2. Developer PC
    • 1.2.1. SDK setting
    • 1.2.2. Build
    • 1.2.3. Azure IoT Explorer (preview) setting
    • 1.2.4. Serial terminal open
• 2. Run the example
  • 2.1. Copy main.uf2 file into your W5x00-EVB-Pico
  • 2.2. Send 3 messages from IoT device to IoT Hub
  • 2.3. Receive 3 C2D messages from IoT Hub to IoT device
    • 2.3.1. How to send C2D message with Azure IoT Explorer
    • 2.3.2. Getting C2D messages

1. Prepare IoT Hub and Device for this example

1.1. Azure portal

[MUST] Same as 1.1. Azure portal in _1_APP_TELEMETRY_manual.md

1.2. Developer PC

1.2.1. SDK setting

In the following WIZnet-PICO-AZURE-C/exmaples/main.c source file, find the line similar to this and replace it as you want:

(...)

// The application you wish to use should be uncommented
//
//#define APP_TELEMETRY
#define APP_C2D
//#define APP_CLI_X509
//#define APP_PROV_X509

// The application you wish to use DHCP mode should be uncommented
#define _DHCP
static wiz_NetInfo g_net_info =
    {
        .mac = {0x00, 0x08, 0xDC, 0x12, 0x34, 0x56}, // MAC address
        .ip = {192, 168, 11, 2},                     // IP address
        .sn = {255, 255, 255, 0},                    // Subnet Mask
        .gw = {192, 168, 11, 1},                     // Gateway
        .dns = {8, 8, 8, 8},                         // DNS server
#ifdef _DHCP
        .dhcp = NETINFO_DHCP // DHCP enable/disable
#else
        // this example uses static IP
        .dhcp = NETINFO_STATIC
#endif
};

Edit the WIZnet-PICO-AZURE-C/examples/sample_certs.c entering the proper connection string and key value from the Azure Portal:

/* Paste in the your iothub connection string  */
const char pico_az_connectionString[] = "[device connection string]";

1.2.2. Build

Run make command

(PWD) WIZnet-PICO-AZURE-C/build/examples
$ make
[ 12%] Built target AZURE_SDK_FILES
[ 12%] Built target bs2_default
[ 12%] Built target bs2_default_padded_checksummed_asm
[ 12%] Built target W5100S_FILES
[ 13%] Built target ETHERNET_FILES
[ 13%] Built target DHCP_FILES
[ 13%] Built target DNS_FILES
[ 21%] Built target SNTP_FILES
[ 43%] Built target AZURE_SDK_PORT_FILES
[ 43%] Performing build step for 'ELF2UF2Build'
[100%] Built target elf2uf2
[ 43%] No install step for 'ELF2UF2Build'
[ 43%] Completed 'ELF2UF2Build'
[ 44%] Built target ELF2UF2Build
[ 56%] Built target mbedcrypto
[ 58%] Built target mbedx509
[ 59%] Built target mbedtls
[ 66%] Built target TIMER_FILES
[ 73%] Built target SPI_FILES
Consolidate compiler generated dependencies of target main
[ 75%] Building C object examples/CMakeFiles/main.dir/main.c.obj
[ 75%] Linking CXX executable main.elf
[100%] Built target main

1.2.3. Azure IoT Explorer (preview) setting

[MUST] Same as1.2.3. Azure IoT Explorer (preview) setting in _1_APP_TELEMETRY_manual.md

1.2.4. Serial terminal open

Open "COM" port to see debug code

2. Run the example

This example has 2 functions:

1. Send 3 messages from IoT device.
2. Receive 3 C2D (Cloud to Device) messages.

2.1. Copy main.uf2 file into your W5x00-EVB-Pico

(PWD) WIZnet-PICO-AZURE-C/build/examples
$ cp main.uf2 /f/

2.2. Send 3 messages from IoT device to IoT Hub

Send 3 messages same as _1_APP_TELEMETRY_manual.md

You can get result of "function 1" result as below "Azure IoT Explorer" window.

2.3. Receive 3 C2D messages from IoT Hub to IoT device

2.3.1. How to send C2D message with Azure IoT Explorer

For "function 2", you can send C2D messages to your device with "Azure IoT Explorer" program as follows:

2.3.2. Getting C2D messages

Then, you can see the received #1 C2D message through your "Serial Terminal" window as below:

• C2D Message #2

• C2D Message #3