NXP IMX8MM-EVK

Evaluation kit

• EVK

Getting started with the EVK

Installing Linux

• Download Linux binary demo
• Download UUU

~$ chmod a+x UUU
~$ sudo ./uuu <linux_images_MX8MMEVK.zip>

• Boot switch setup
• Linux User Guide
• Reference Manual

MCUXpresso SDK

• Download SDK.
• We used MCUXpresso version 2.11.1.
• NOTE: Initialization of pins in pinmux.c of few examples is missing (fixed in new version 2.12.0).

void BOARD_InitBootPins(void)
{
    BOARD_InitPins(); //missing function added
}

• PinMux Tool
• Set environment:

export ARMGCC_DIR=/gcc-arm-11.2-2022.02-x86_64-arm-none-eabi

• To build example run

/armgcc/build_.sh

• Running application on Cortex-4:
• Setup TFTP on PC.

~$ sudo apt update
~$ sudo apt install tftpd-hpa
~$ sudo systemctl status tftpd-hpa
Change username and directory:
~$ sudo nano /etc/default/tftpd-hpa
~$ sudo mkdir /tftp
~$ sudo chown tftp:tftp /tftp
~$ sudo systemctl restart tftpd-hpa
~$ sudo systemctl status tftpd-hpa

• Copy .bin to tftp/

~$ sudo cp release/app.bin ~/tftp/
~$ sudo chown tftp:tftp ~/tftp/app.bin

• Open terminal on PC with following config:

~$ sudo picocom -b 112500 /dev/ttyUSB*

• Load u-boot on IMX8MM-EVK
• To run TCM builds from u-boot:

=> setenv <env_name> "dhcp; setenv serverip <ip_addr>; tftp 0x48000000 .bin; cp.b 0x48000000 0x7e0000 0x20000; bootaux 0x7e0000"
=> saveenv
=> run <env_name>

• Open terminal for Cortex-M4 to see serial output from the app running on it.

Testing Examples

ECSPI Driver

• Interrupt B2B Transfer master as loopback using single board.
• Connect MOSI and MISO pins physically on board (J1003-PIN_19-ECSPI2_MOSI & J1003-PIN_21-ECSPI2_MISO ).
• Edition in driver code:

Assign masterTxData and masterRxData buffer to escpi_transfer_t object.

GPIO Driver

• Used led_output example
• Digital output -> Digital input (rising edge triggered)
• Changing pin from ECSPI2_MOSI to SAI5_RXD0 in pinmux.c.
• Refer to PinMux Tool for more information.
• Interrupt Enabled on GPIO pin J1003-38 (originally configured to J1003-19).
• Implement GPIO3_Combined_16_31_IRQHandler() function

Extras

• Logic Analyzer
• ARM GCC Toolchain

Spark SDK & UWB

• Historical Background of UWB: https://semiwiki.com/5g/283112-the-story-of-ultra-wideband-part-1-the-genesis/

Tools and Software

• SDK & Documentation: https://www.sparkmicro.com/products/#SDK
• Version we used: v1.0.0 CubeIDE for debugging.
• STM32 ST-Link V2.
• STM32CubeProgrammer to flash .bin files.

Testing Examples

• Add SDK to the workspace in CubeIDE.
• Connect the EVK board via STM32 ST-Link V2.
• Build the project and start debugging.

Audio Streaming

• Added necessary functions and header files for serial output as implemented in Hello World example.

void iface_board_init(void)
{     
    evk_init();
    usb_detect_callback_init();
    usb_connection_init(); 
}

void evk_usb_device_cdc_send_buf(uint8_t *buf, uint16_t buf_len);

• Serial output

~$ sudo picocom -b 112500 /dev/ttyACM* 

• Generating a custom sine wave and sending it though wireless core.
• Codec writes data into DMA then DMA transfer the data to wireless core.
• Implementing our sine wave where the codec generates buffer and starts the DMA; "iface_audio_evk.c".
• Amplitude = 32767.0
• Sample Rate = 48kHz

uint8_t dummy[256];
static uint16_t ep_max98091_action_produce(void *instance, uint8_t *data, uint16_t size)
{
    (void)instance;
    int16_t *samples = (int16_t *)data;
    uint16_t samples_count = size / 2;
    for (int n = 0; n < samples_count / 2; n = n + 2)
    {
        samples[n] = wave[sample_count];
        samples[n + 1] = samples[n];
        sample_count += 1;
        if (sample_count >= 48000)
        {
            sample_count = 0;
        }
    }
    evk_audio_sai_read_non_blocking(dummy, size);
    return 0;
}
static void ep_max98091_start_produce(void *instance)
{
    (void)instance;
    for (int n = 0; n < 48000; n++)
    {
        wave[n] = (double)(AMP * sinf((M_PI * 2 / SAMPLE_RATE) * FREQUENCY * n));
    }
    evk_audio_sai_start_read_non_blocking();
}

Implement Spark Stack on MCUXpresso SDK