uart1 TX not working on nRF7002DK

RE: uart1 TX not working on nRF7002DK

Michael Zeng — Mon, 21 Aug 2023 00:51:01 GMT

Firstly, appears that I did not handle the UART_RX_BUF_REQUEST event correctly. The 2nd example provided a good reference.

Secondly, I do not know why, but the UART communication did not work until I started a new project using SDK 2.4.0 (the old project was on 2.3.99, I perhaps messed with the configs in the past and forgot), and then pasted all the same code in.

Thank you for your help Kenneth.

RE: uart1 TX not working on nRF7002DK

Kenneth — Thu, 17 Aug 2023 09:21:16 GMT

I can find there are several projects that use the UART driver, I suggest to use them as reference, some of them are:

\nrf\samples\bluetooth\central_uart\src\main.c
\nrf\samples\bluetooth\peripheral_uart\src\main.c

\nrf\samples\peripheral\lpuart\src\main.c
\nrf\tests\drivers\lpuart\src\main.c
\zephyr\tests\drivers\uart\uart_async_api\src\test_uart_async.c

Kenneth

RE: uart1 TX not working on nRF7002DK

Michael Zeng — Wed, 16 Aug 2023 16:56:41 GMT

Hi Kenneth, thanks for the reply. I tried that as well:

#include <zephyr/kernel.h>
#include <zephyr/drivers/gpio.h>
#include <zephyr/drivers/i2c.h>
#include <zephyr/sys/printk.h>
#include <zephyr/drivers/uart.h>

#define SLEEP_TIME_MS   1000


const struct device *uart = DEVICE_DT_GET(DT_NODELABEL(uart0));

#define RECEIVE_BUFF_SIZE 10
static uint8_t rx_buf[RECEIVE_BUFF_SIZE]; //A buffer to store incoming UART data 


static void uart_cb(const struct device *dev, struct uart_event *evt, void *user_data)
{
	switch (evt->type) {
	
	case UART_TX_DONE:
		// do something
		break;

	case UART_TX_ABORTED:
		// do something
		break;
		
	case UART_RX_RDY:
		printk("	evt->data.rx.len: %d\n", evt->data.rx.len);
		printk("	evt->data.rx.offset: %d\n", evt->data.rx.offset);
		printk("    data: ");
		for (int i=0; i < evt->data.rx.len; i++) {
			printk("%02X ", evt->data.rx.buf[evt->data.rx.offset + i]);
		}
		printk("\n");
		break;

	case UART_RX_BUF_REQUEST:
		printk("UART_RX_BUF_REQUEST\n");
		int err = uart_rx_buf_rsp(uart, rx_buf, sizeof(rx_buf));
		if (err) {
			printk("uart_rx_buf_rsp errored with code %d.\n", err);
		}
		break;

	case UART_RX_BUF_RELEASED:
		printk("UART_RX_BUF_RELEASED\n");
		break;
		
	case UART_RX_DISABLED:
		printk("UART_RX_DISABLED\n");
		uart_rx_enable(uart, rx_buf, sizeof(rx_buf), SYS_FOREVER_US);
		break;

	case UART_RX_STOPPED:
		printk("UART_RX_STOPPED\n");
		break;
		
	default:
		break;
	}
}


int main(void)
{
	k_msleep(1000);
	printk("Starting Program..\n");

	int ret;

	// UART
	if (!device_is_ready(uart)) {
		printk("uart not ready. returning.\n");
		return;
	}

	const struct uart_config uart_cfg = {
		.baudrate = 115200,
		.parity = UART_CFG_PARITY_NONE,
		.stop_bits = UART_CFG_STOP_BITS_1,
		.data_bits = UART_CFG_DATA_BITS_8,
		.flow_ctrl = UART_CFG_FLOW_CTRL_NONE
	};
	ret = uart_configure(uart, &uart_cfg);
	if (ret == -ENOSYS) {
		return -ENOSYS;
	}

	ret = uart_callback_set(uart, uart_cb, NULL);
	if (ret) {
		return ret;
	}

	ret = uart_rx_enable(uart, rx_buf, sizeof(rx_buf), SYS_FOREVER_US);
	if (ret) {
		printk("uart_rx_enable faild with ret=%d\n", ret);
		return ret;
	}

	int ctr = 0;
	while (1) {

		printk("uart0_rx looping... %d\n", ctr);
		ctr++;

		k_msleep(SLEEP_TIME_MS);

	}
	return 0;
}

The call to uart_rx_buf_rsp() does not return an error. However, the uart communication still does not work.

Hard to explain why the receiver works perfectly fine when using an Arduino to transmit UART data.

Thanks,

Michael

RE: uart1 TX not working on nRF7002DK

Kenneth — Wed, 16 Aug 2023 07:41:50 GMT

[quote user="Michael Zeng"]The receiver callback function receives a single "UART_RX_BUF_REQUEST" upon powering on, but never receives any other events.[/quote]

You are suppose to provide a buffer on this event by calling uart_rx_buf_rsp().

Kenneth

RE: uart1 TX not working on nRF7002DK

Michael Zeng — Wed, 16 Aug 2023 07:16:14 GMT

I tested the nRF7002DK with the uart_tx code today with a logic analyzer; the logic analyzer (with the exact data rate, stop bit, parity, etc. that I programmed in the receiver) receives the transmitted data successfully.

I also tested my nRF7002DK with the uart receiver code again using an Arduino to transmit data. The receiver received and printed the data from the Arduino successfully.

However, when I combine the nRF7002DK uart_tx code with the nRF7002DK receiver code, it doesn't work. The receiver callback function receives a single "UART_RX_BUF_REQUEST" upon powering on, but never receives any other events.

This is my receiver code, if it helps:

#include <zephyr/kernel.h>
#include <zephyr/drivers/gpio.h>
#include <zephyr/drivers/i2c.h>
#include <zephyr/sys/printk.h>
#include <zephyr/drivers/uart.h>

#define SLEEP_TIME_MS   1000


const struct device *uart = DEVICE_DT_GET(DT_NODELABEL(uart0));


static void uart_cb(const struct device *dev, struct uart_event *evt, void *user_data)
{
	switch (evt->type) {
	
	case UART_TX_DONE:
		// do something
		break;

	case UART_TX_ABORTED:
		// do something
		break;
		
	case UART_RX_RDY:
		printk("	evt->data.rx.len: %d\n", evt->data.rx.len);
		printk("	evt->data.rx.offset: %d\n", evt->data.rx.offset);
		printk("    data: ");
		for (int i=0; i < evt->data.rx.len; i++) {
			printk("%02X ", evt->data.rx.buf[evt->data.rx.offset + i]);
		}
		printk("\n");
		break;

	case UART_RX_BUF_REQUEST:
		printk("UART_RX_BUF_REQUEST\n");
		break;

	case UART_RX_BUF_RELEASED:
		printk("UART_RX_BUF_RELEASED\n");
		break;
		
	case UART_RX_DISABLED:
		printk("UART_RX_DISABLED\n");
		break;

	case UART_RX_STOPPED:
		printk("UART_RX_STOPPED\n");
		break;
		
	default:
		break;
	}
}


int main(void)
{
	k_msleep(1000);
	printk("Starting Program..\n");

	int ret;

	// UART
	if (!device_is_ready(uart)) {
		printk("uart not ready. returning.\n");
		return;
	}

	const struct uart_config uart_cfg = {
		.baudrate = 115200,
		.parity = UART_CFG_PARITY_NONE,
		.stop_bits = UART_CFG_STOP_BITS_1,
		.data_bits = UART_CFG_DATA_BITS_8,
		.flow_ctrl = UART_CFG_FLOW_CTRL_NONE
	};
	ret = uart_configure(uart, &uart_cfg);
	if (ret == -ENOSYS) {
		return -ENOSYS;
	}

	ret = uart_callback_set(uart, uart_cb, NULL);
	if (ret) {
		return ret;
	}

	static uint8_t rx_buf[3]; //A buffer to store incoming UART data 
	uart_rx_enable(uart, rx_buf, sizeof rx_buf, SYS_FOREVER_US);

	int ctr = 0;
	while (1) {

		printk("uart0_rx looping... %d\n", ctr);
		ctr++;

		k_msleep(SLEEP_TIME_MS);
		
	}
	return 0;
}

Any other ideas?

RE: uart1 TX not working on nRF7002DK

Kenneth — Tue, 15 Aug 2023 09:10:14 GMT

Hello,

I don't have access to a nRF7002-DK today, but can try to replicate this before the weekend.

If you have access to a logic analyzer you might look at the TX pin just to check if voltage and baudrate is correct.

Kenneth

RE: uart1 TX not working on nRF7002DK

Michael Zeng — Tue, 15 Aug 2023 07:36:37 GMT

Yes, after changing the overlay, I deleted the build folder and created a new build configuration. Clicking "Remove Build Configuration" in VSCode and creating a new Build Configuration should have the same effect though, right?

The issue seems to persist even with a different TX pin. For example, I tried this new overlay file using P0.09 and P0.10 for uart1 (and re-wired the dev kits appropriately):

// Allow uart1 to be used as a normal UART instead of forwarding to network core for serial logging
/delete-node/ &gpio_fwd;

&pinctrl {
	i2c1_default: i2c1_default {
		group1 {
			psels = <NRF_PSEL(TWIM_SDA, 1, 2)>,
				<NRF_PSEL(TWIM_SCL, 1, 3)>;
		};
	};

	i2c1_sleep: i2c1_sleep {
		group1 {
			psels = <NRF_PSEL(TWIM_SDA, 1, 2)>,
				<NRF_PSEL(TWIM_SCL, 1, 3)>;
			low-power-enable;
		};
	};

	uart0_default: uart0_default {
		group1 {
			psels = <NRF_PSEL(UART_TX, 0, 20)>,
				<NRF_PSEL(UART_RTS, 0, 19)>;
		};
		group2 {
			psels = <NRF_PSEL(UART_RX, 0, 22)>,
				<NRF_PSEL(UART_CTS, 0, 21)>;
			bias-pull-up;
		};
	};

	uart0_sleep: uart0_sleep {
		group1 {
			psels = <NRF_PSEL(UART_TX, 0, 20)>,
				<NRF_PSEL(UART_RX, 0, 22)>,
				<NRF_PSEL(UART_RTS, 0, 19)>,
				<NRF_PSEL(UART_CTS, 0, 21)>;
			low-power-enable;
		};
	};

	pwm0_default: pwm0_default {
		group1 {
			psels = <NRF_PSEL(PWM_OUT0, 1, 6)>;
		};
	};

	pwm0_sleep: pwm0_sleep {
		group1 {
			psels = <NRF_PSEL(PWM_OUT0, 1, 6)>;
			low-power-enable;
		};
	};

	qspi_default: qspi_default {
		group1 {
			psels = <NRF_PSEL(QSPI_SCK, 0, 17)>,
				<NRF_PSEL(QSPI_IO0, 0, 13)>,
				<NRF_PSEL(QSPI_IO1, 0, 14)>,
				<NRF_PSEL(QSPI_IO2, 0, 15)>,
				<NRF_PSEL(QSPI_IO3, 0, 16)>,
				<NRF_PSEL(QSPI_CSN, 0, 18)>;
		};
	};

	qspi_sleep: qspi_sleep {
		group1 {
			psels = <NRF_PSEL(QSPI_SCK, 0, 17)>,
				<NRF_PSEL(QSPI_IO0, 0, 13)>,
				<NRF_PSEL(QSPI_IO1, 0, 14)>,
				<NRF_PSEL(QSPI_IO2, 0, 15)>,
				<NRF_PSEL(QSPI_IO3, 0, 16)>,
				<NRF_PSEL(QSPI_CSN, 0, 18)>;
			low-power-enable;
		};
	};

    uart1_default: uart1_default {
		group1 {
			psels = <NRF_PSEL(UART_TX, 0, 10)>;
		};
		group2 {
			psels = <NRF_PSEL(UART_RX, 0, 9)>;
			bias-pull-up;
		};
	};

	uart1_sleep: uart1_sleep {
		group1 {
			psels = <NRF_PSEL(UART_TX, 0, 10)>,
				<NRF_PSEL(UART_RX, 0, 9)>;
			low-power-enable;
		};
	};

	spi3_default: spi3_default {
		group1 {
			psels = <NRF_PSEL(SPIM_SCK, 1, 15)>,
				<NRF_PSEL(SPIM_MISO, 1, 14)>,
				<NRF_PSEL(SPIM_MOSI, 1, 13)>;
		};
	};

	spi3_sleep: spi3_sleep {
		group1 {
			psels = <NRF_PSEL(SPIM_SCK, 1, 15)>,
				<NRF_PSEL(SPIM_MISO, 1, 14)>,
				<NRF_PSEL(SPIM_MOSI, 1, 13)>;
			low-power-enable;
		};
	};

	spi4_default: spi4_default {
		group1 {
			psels = <NRF_PSEL(SPIM_SCK, 0, 8)>,
				<NRF_PSEL(SPIM_MISO, 0, 10)>,
				<NRF_PSEL(SPIM_MOSI, 0, 9)>;
		};
	};

	spi4_sleep: spi4_sleep {
		group1 {
			psels = <NRF_PSEL(SPIM_SCK, 0, 8)>,
				<NRF_PSEL(SPIM_MISO, 0, 10)>,
				<NRF_PSEL(SPIM_MOSI, 0, 9)>;
			low-power-enable;
		};
	};

};


&uart1 {
	status = "okay";
	current-speed = <115200>;
	pinctrl-0 = <&uart1_default>;
	pinctrl-1 = <&uart1_sleep>;
	pinctrl-names = "default", "sleep";
};

I've also tried swapping which DK is transmitting and which is receiving, which did not fix the issue.

Also, in case it helps, this is the code running on the nRF7002DK receiver: github.com/.../nRF7002DK-UART-Rx

RE: uart1 TX not working on nRF7002DK

Kenneth — Mon, 14 Aug 2023 10:49:01 GMT

I assumed you also deleted the build folder after doing this change?

Also, can you try a different pin for TX?
https://github.com/nrfconnect/sdk-nrf/blob/v2.4.0/boards/arm/nrf7002dk_nrf5340/nrf5340_cpuapp_common-pinctrl.dtsi#L75

Kenneth