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Re: UART Communication problems at 921600

Posted: Wed Nov 13, 2019 7:00 am
by ESP_Faye
Crypth wrote:
Mon Nov 11, 2019 5:23 pm
Is there any chance the AT library will end up open to the public?


Sorry that AT lib is not open source, and maybe it will not change to open source in the future. Sorry for the inconvenience.

Re: UART Communication problems at 921600

Posted: Thu Nov 14, 2019 7:40 am
by ESP_houwenxiang
LukeSkyWire wrote:
Wed Jun 20, 2018 11:05 am
What I have noticed however is if I send 1400 bytes the uart_read_bytes returns a value in the range of 1390.
If I send 600 bytes I get a len of approx 596.
Hi, LukeSkyWire

Have you enabled hardware flow control? At 1M baud, the CPU can read out the data in fifo in time. But At 2M baud-rate, the CPU cannot read out the data in fifo in time, resulting in data loss. When enable the flow control, the baud-rate can reach 5M.

thanks !!

Re: UART Communication problems at 921600

Posted: Thu Nov 14, 2019 5:06 pm
by Crypth
ESP_Faye wrote:
Wed Nov 13, 2019 7:00 am
Crypth wrote:
Mon Nov 11, 2019 5:23 pm
Is there any chance the AT library will end up open to the public?


Sorry that AT lib is not open source, and maybe it will not change to open source in the future. Sorry for the inconvenience.
That's all right with me if we could get it working without errors in the uart communication.

I'm in the process of setting up HW control.
When compiling IDF and AT with 8,0,1,3, it doesn't seem to change anything at all. It chatters like it's not set after a reset.
When we send the UART_CUR command with HW control, the behavior changes radically.
Are we supposed to change the HW control on the host side after we send the UART_CUR changes to HW control, not from start?

Re: UART Communication problems at 921600

Posted: Mon May 25, 2020 5:47 pm
by gunar.kroeger
ESP_houwenxiang wrote:
Thu Nov 14, 2019 7:40 am
LukeSkyWire wrote:
Wed Jun 20, 2018 11:05 am
What I have noticed however is if I send 1400 bytes the uart_read_bytes returns a value in the range of 1390.
If I send 600 bytes I get a len of approx 596.
Hi, LukeSkyWire

Have you enabled hardware flow control? At 1M baud, the CPU can read out the data in fifo in time. But At 2M baud-rate, the CPU cannot read out the data in fifo in time, resulting in data loss. When enable the flow control, the baud-rate can reach 5M.

thanks !!
Is this the official maximum baudrate achievable without hw flow control? Could you link the documentation specifying this limit? I only remember seeing the 5M limit and no requirement for hw flow control connections mention, but I could be wrong.
I'm also trying to get the maximum throughput with uart using the events example, but getting fifo overflow events