About the use of gpiote and dppi of nrf5340

[mingjkl]

I want to use nRF5340's GPIOTE and DPPI implementation, pull up PA_SWITCH_CTX_PIN when NRF_RADIO->EVENTS_RXREADY is triggered, and pull down PA_SWITCH_CTX_PIN when NRF_RADIO->EVENTS_TXREADY is triggered;

I wrote the following code with reference to demo \v2.0.0\zephyr\samples\boards\nrf\nrfx. When I found out that using this method can only achieve one event for one task. Please how should I modify it.

	static uint8_t tx_ppi_chaannel;
	
	nrfx_gpiote_init(99);

	nrfx_gpiote_out_config_t const out_config = {
		.action = NRF_GPIOTE_POLARITY_HITOLO,
		.init_state = 1,
		.task_pin = true,
	};

	nrfx_gpiote_out_init(PA_SWITCH_CTX_PIN, &out_config);
	nrfx_gpiote_out_task_enable(PA_SWITCH_CTX_PIN);

	nrfx_dppi_channel_alloc(&tx_ppi_chaannel);

	nrfx_gppi_channel_endpoints_setup(tx_ppi_chaannel, 
		(uint32_t)&NRF_RADIO->EVENTS_RXREADY,
		nrf_gpiote_task_address_get(NRF_GPIOTE,
			nrfx_gpiote_out_task_get(PA_SWITCH_CTX_PIN)));

	nrfx_dppi_channel_enable(tx_ppi_chaannel);

[mingjkl]

I changed the implementation method below, it seems that the function I want has been successfully implemented, please help me confirm.

#define PA_SWITCH_CTX_PIN NRF_GPIO_PIN_MAP(1,9)

void esb_pa_ppi_init(void)
{


	uint8_t tx_ppi_chaannel;
	uint8_t rx_ppi_chaannel;

	NRF_GPIOTE->CONFIG[0] = GPIOTE_CONFIG_MODE_Task << GPIOTE_CONFIG_MODE_Pos |
					GPIOTE_CONFIG_OUTINIT_High << GPIOTE_CONFIG_OUTINIT_Pos |
					PA_SWITCH_CTX_PIN << GPIOTE_CONFIG_PSEL_Pos;

	nrfx_dppi_channel_alloc(&tx_ppi_chaannel);
	printk("tx ppi ch %d\r\n", tx_ppi_chaannel);
	NRF_GPIOTE->SUBSCRIBE_CLR[0] = DPPIC_SUBSCRIBE_CHG_EN_EN_Msk | tx_ppi_chaannel;
	NRF_RADIO->PUBLISH_RXREADY = DPPIC_SUBSCRIBE_CHG_EN_EN_Msk | tx_ppi_chaannel;
	nrfx_dppi_channel_enable(tx_ppi_chaannel);

	nrfx_dppi_channel_alloc(&rx_ppi_chaannel);
	printk("rx ppi ch %d\r\n", rx_ppi_chaannel);
	NRF_GPIOTE->SUBSCRIBE_SET[0] = DPPIC_SUBSCRIBE_CHG_EN_EN_Msk | rx_ppi_chaannel;
	NRF_RADIO->PUBLISH_TXREADY = DPPIC_SUBSCRIBE_CHG_EN_EN_Msk | rx_ppi_chaannel;

	nrfx_dppi_channel_enable(rx_ppi_chaannel);


}

[Håkon Alseth]

Hi,

 

ESB does not have PA/LNA support, but the code that you're using here, with selective_auto_ack=true, runs at my end:

Channel 0 is a debug signal, cleared after TX_FAILED event in the esb handler, while channel 1 is your dppi/gpiote routine.

 

Please note that your chosen PA/LNA will have timing requirements to when the PA should be turned off, and the event coming from the radio will turn off the pin immediately after the last bit has been transferred on-air. This can be problematic for some PA's, and if this is the case for your PA; I would recommend that you use a timer to postpone de-asserting the pin.

 

Kind regards,

Håkon

[mingjkl]

Thank you very much for your technical support and reminders.