Search found 6 matches

by brunohpg
Fri Apr 12, 2024 8:32 pm
Forum: General Discussion
Topic: TX UART open drain mode
Replies: 2
Views: 618

Re: TX UART open drain mode

I saw that new implementation connects gpio to gpio out signal when set direction. I think one pad can be connected to only one signal. Then the serial signal are disconnected. static esp_err_t gpio_output_enable(gpio_num_t gpio_num) { GPIO_CHECK(GPIO_IS_VALID_OUTPUT_GPIO(gpio_num), "GPIO output gpi...
by brunohpg
Fri Apr 12, 2024 7:44 pm
Forum: General Discussion
Topic: TX UART open drain mode
Replies: 2
Views: 618

Re: TX UART open drain mode

Did you found a way to use od in uart tx?

In esp-idf 4.4 it works using:

Code: Select all

gpio_set_direction(tx_io_num, GPIO_MODE_OUTPUT_OD)
But not in 5.2.
by brunohpg
Fri Jun 21, 2019 11:58 am
Forum: ESP-IDF
Topic: Use of UART_RX_IDLE_THRHD
Replies: 2
Views: 2840

Re: Use of UART_RX_IDLE_THRHD

I do not think so. I activated all interrupts and set multiple values for this property, but I could not find what it would be. UART_BRK_DET_INT: Triggered when the receiver detects at 0 level after the STOP bit. UART_TX_BRK_IDLE_DONE_INT: Triggered when the transmitter's idle state has been kept to...
by brunohpg
Wed Jun 19, 2019 8:22 pm
Forum: ESP-IDF
Topic: Use of UART_RX_IDLE_THRHD
Replies: 2
Views: 2840

Use of UART_RX_IDLE_THRHD

Hi, there is a configuration "UART_RX_IDLE_THRHD" on UART, but I don't found any use for it. Can someone explain the use of "UART_RX_IDLE_THRHD"? From Reference Manual (p.361): UART_RX_IDLE_THRHD When the receiver takes more time to receive Byte data than what this register indicates, it will produc...
by brunohpg
Wed May 29, 2019 6:31 pm
Forum: ESP-IDF
Topic: UART Baud Timing Pattern Interrupt / J1708
Replies: 4
Views: 3793

Re: UART Baud Timing Pattern Interrupt / J1708

For APB_CLK as source for UART, it's 10 baud cycles, i.e., 100 bits (without parity). But I don't know what is the default source clock. I think it's APB_CLK. From Reference Manual: UART_RX_TOUT_THRHD This register is used to configure the UART receiver’s timeout value when receiving a byte. When us...
by brunohpg
Tue May 28, 2019 5:54 pm
Forum: ESP-IDF
Topic: UART Baud Timing Pattern Interrupt / J1708
Replies: 4
Views: 3793

UART Baud Timing Pattern Interrupt / J1708

Hi, I want to implement J1708 with ESP32. J1708 is a modified version of RS485. I am using RS485 UART with modified tranceiver and everything is going well for sending and receiving data. But the J1708 has a standard of time to distinguish messages. It's simple: After a message, consisting of a maxi...