Newbie UART write

[urbanze]

How to convert uint8_t to const char* ?

I trying to write some bytes (>127) but uart_write_bytes() only accept const char (<128). Like this:

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uint8_t SS[44];
for (int16_t i = 0; i < 44; i++)
{
	uart_write_bytes(UART_NUM_0, (const char*)SS[i], 1);
}

[chegewara]

How did you init uart with:

Code: Select all

    uart_driver_install(UART, RX_BUF_SIZE, TX_BUF_SIZE, QUEUE_SIZE, &uart_queue, FLAGS);

[urbanze]

How did you init uart with:

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    uart_driver_install(UART, RX_BUF_SIZE, TX_BUF_SIZE, QUEUE_SIZE, &uart_queue, FLAGS);

I not understanding, This not use any parameter with const char...?

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uart_driver_install(UART_NUM_0, 1024, 0, 0, NULL, 0);

[ESP_Sprite]

Force-casting them to a char* should work. No specific need to add the const here, the const in this case is a promise from the function that it won't change the data a caller passes onto it.

[urbanze]

Force-casting them to a char* should work. No specific need to add the const here, the const in this case is a promise from the function that it won't change the data a caller passes onto it.

Well, no logic, but worked

Code: Select all

for (int16_t i = 0; i < 44; i++)
{
	const char x = (int8_t)SS[i];
	uart_write_bytes(UART_NUM_0, &x, 1);
}

[ESP_Sprite]

Eh, it's not that pretty but it'll work, and the compiler will probably optimize it to the same instructions as if it would if you casted it.