ESP8266 Community Forum

- Mon Sep 29, 2014 1:33 am #1004 I hope there will soon be an AT command to change the baud rate.

One problem is that 115200 is marginal on a 16 MHz Arduino, and too inaccurate on an 8 MHz Arduino.

Option 1: If only a few fixed speeds can be provided, include 76800 (twice 38400) which is good for both Ardu speeds, with only 0.2% error.

Option 2: Better still, allow arbitrary non-standard baud rates to be requested, select closest actual rate supported (would be nice to echo the actual rate out before changing).

Also: of course it would be nice be able to go above 115200 for speed reasons - say, 250000 baud, which the Arduino can support with 0 error. Or even 500 K or 1 Mbps.

- Mon Sep 29, 2014 11:21 am #1018 This looks like it should be possible. Unlsess I am misreading things for our board, it looks like the following code is what handles it:

Code: Select alluart_div_modify(uart_no, UART_CLK_FREQ / (UartDev.baut_rate));

And, that means we have to have divisors of UART_CLK_FREQ which is CPU_CLK_FREQ, which looks like it is 80MHz.

I don't have a setup for the moment where I can slam an AVR into a 2 MHz serial clock mode, but, I'll see what happens.

There is another problem, though. That's that it's likely one could overflow the serial fifo if we transfer that fast. Additionally, does anyone know if there are other interrupts that could fire that could cause the UART interrupt not to be called in time?

- Tue Sep 30, 2014 5:22 pm #1065 This would be a very important feature. I think many of us are struggling with the SoftwareSerial limitation issue with Arduino. Reducing the baudrate of the module would solve this.

- Thu Oct 02, 2014 3:27 pm #1132 2.1% bit error (source: http://www.wormfood.net/avrbaudcalc.php ... detables=1 ) isn't very bad... It should be workable.