Custom ESP32C3 Board SPI Causes Program not to run...

[jumper385]

Hi All,

I've come up with a custom esp32c3 board however, I cannot get my program to work when i use CONFIG_SPI=y. Has anybody else come across this before and know what the issue is? I've provided the relevant code snippets and a screenshot of the schematic...

// main.c
#include <zephyr/kernel.h>
#include <zephyr/drivers/gpio.h>
#include <zephyr/device.h>
#include <zephyr/drivers/spi.h>

#define LED DT_NODELABEL(led_red)
#define SPI_NODE DT_ALIAS(spibus)

struct gpio_dt_spec led = GPIO_DT_SPEC_GET(LED, gpios);
struct device *spi_dev = DEVICE_DT_GET(SPI_NODE);

// temporary values for debugging
uint16_t ch1;
float vout, vout_uc;

float convert(uint16_t adc_reading, float A, float B, float C, bool isCompensated) {
   // 12-Bit ADC Code Conversion
}

void main()
{
        printk("Hello world from entry\n");
        // Check if SPI is ready...
	if (!device_is_ready(spi_dev))
	{
		printk("Couldn not setup SPI Bus...\n");
		return;
	}
        
        // Additional GPIO/Program Configs

	for (;;)
	{
                 printk("Hello world from loop\n");
                 // Setup SPI Buffers
		uint8_t adc[2];

		struct spi_buf rx_buf = {.buf = &adc, .len = 4};
		struct spi_buf_set rx_bufs = {.buffers = &rx_buf, .count = 1};

		const struct spi_config adc_cfg = {
			.frequency = DT_PROP(SPI_NODE, clock_frequency),
			.operation = SPI_OP_MODE_MASTER | SPI_TRANSFER_MSB | SPI_WORD_SET(8),
			.cs = SPI_CS_CONTROL_INIT(DT_NODELABEL(mcp3201), 0),
		};
                
                 // Read SPI2
		int ret = spi_read(spi_dev, &adc_cfg, &rx_bufs);
		if (ret != 0)
		{
			printk("Error reading...\n");
			gpio_pin_set_dt(&led, 1);
			return;
		}
                
		ch1 = adc[0] << 8 | adc[1];
		vout = convert(ch1, .108, 1e8, 2.0f, true);

		// additional program loop code

		k_msleep(100);
	}
	return 1;
}

// prj.conf

CONFIG_SPI=y
CONFIG_GPIO=y

// esp32c3_devkitm.overlay

&pinctrl {
    spim2_default: spim2_default {
        group1 {
            pinmux = <SPIM2_MISO_GPIO13>,
                     <SPIM2_SCLK_GPIO12>,
                     <SPIM2_MOSI_GPIO11>;
        };
    };
};

/ {
    chosen {
        zephyr,console = &usb_serial;
        zephyr,shell-uart = &usb_serial;
    };
    leds {
        compatible = "gpio-leds";
        // GPIO Output Configuration
    };

    buttons {
        compatible = "gpio-keys";

        // GPIO Input Configuration
    };

    aliases {
        spibus = &spi2;
    };
};


&spi2 {
    status = "okay";
    cs-gpios = <&gpio0 16 GPIO_ACTIVE_LOW>;
    clock-frequency = <200000>;
    pinctrl-0 = <&spim2_default>;
    pinctrl-names = "default";

    mcp3201: spi-device@0 {
        compatible = "spi-device";
        spi-max-frequency = <200000>;
        reg = <0x0>;
    };
};

When i flash and monitor the esp32c3, my terminal looks like this:

As seen in the screenshot, the hello world at the main() entry and the for(;;) entry does not print which suggests the program is failing before it even executes... is this a problem that other people have seen? or is this a possible bug? My schematic is attached below...

[xyzzy42]

uint8_t adc[2];
struct spi_buf rx_buf = {.buf = &adc, .len = 4};

This will overflow the buffer. Suggest .len = sizeof(adc), so one can be assured the buffer size and the transfer size always match.