driver: add rs485 half duplex interface support to uart driver (remove ignore tag...

An existing UART driver does not support RS485 half duplex mode.
This task adds this functionality to ESP_IDF UART driver.
driver/uart.c/h: updated to add support of RS485 half duplex mode
examples/peripherals/uart_echo_rs485/main/rs485_example.c: added test example
components/driver/test/test_uart.c: added test of RS485 half duplex mode
docs/en/api-reference/peripherals/uart.rst: updated documentation
test_uart.c: suppress GCC warnings about discarded const qualifiers
uart.rst: remove sphinx warning - "Duplicate explicit target name"
simple change in uart.h file
update (test_uart.c) after rebase from master
update uart.rst, uart.c, rs485_example.c
Update example description in file Readme.md
update uart.c/h, uart.rst, test_uart.c according to review results
update uart.h (uart_set_rx_timeout() description
test_uart.c remove ignore tag

The tests are completed using RS485 adapters hardware connected to two ESP32 WROVER KITs.

TW#13812
Closes https://github.com/espressif/esp-idf/pull/667
Closes https://github.com/espressif/esp-idf/pull/1006

diff --git a/components/driver/test/test_uart.c b/components/driver/test/test_uart.c
index b9f8be9eef54dc52b7a7c1a97d840ce82c6c44e4..0684809fbcae0a8dcbdb326213c523cae94e29b6 100644 (file)
--- a/components/driver/test/test_uart.c
+++ b/components/driver/test/test_uart.c
@@ -317,5 +317,5 @@ static void rs485_master()
 // of function pointers in unity macro expansion. These warnings may be treated as errors during compilation.
 #pragma GCC diagnostic push  // required for GCC
 #pragma GCC diagnostic ignored "-Wdiscarded-qualifiers"
-TEST_CASE_MULTIPLE_DEVICES("RS485 half duplex uart multiple devices test.", "[driver][ignore]", rs485_master, rs485_slave);
+TEST_CASE_MULTIPLE_DEVICES("RS485 half duplex uart multiple devices test.", "[driver]", rs485_master, rs485_slave);
 #pragma GCC diagnostic pop   // require GCC