Dear all,
The new ESP-IDF which updated last week work this sample very well.
But, how much frequancy does the spi-slave reach? thanks.
大家好,
我的英文很差,请见谅。
官网上最新的sdk解决了这个问题。
我现在有个新问题请教各位大神,spi从端能达到的最高速度是多少?主端好像到几十M但是从端似乎跟不上
谢谢
SPI slave mode (example)
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Re: SPI slave mode (example)
If you use random pins, the speed can go up to 20MHz (absolute max) if the signals are well-formed (50% duty cycle, clean edges etc) although a max of 10MHz may be better to keep in mind if you're not sure about the well-formed-ness. If you use the dedicated pins for the SPI peripheral you select, you can get up to 40MHz (again, absolute max) with well-formed signals and 20MHz for random signals.
Re: SPI slave mode (example)
Hi! ESP_Sprite,
Thanks for your reply.
I used the spi-slave sample upon two esp32-kit.
When I raise the sender's speed(ex. .clock_speed_hz=10000000), I receive messy message.
When I reduce the speed to 8MHz(.clock_speed_hz=8000000), it work well.
What's wrong with the spi-slave? Thank you!
我有两个esp32的开发板用于sdk里spi-slave的测试,
当我把发送端速度调到10M( .clock_speed_hz=10000000),收到的都是乱码;
当我把发送端速度调到8M(.clock_speed_hz=8000000),接受正常
spi的从端是否真能达到以上所说的20MHz(甚至是40MHz)?
Thanks for your reply.
I used the spi-slave sample upon two esp32-kit.
When I raise the sender's speed(ex. .clock_speed_hz=10000000), I receive messy message.
When I reduce the speed to 8MHz(.clock_speed_hz=8000000), it work well.
What's wrong with the spi-slave? Thank you!
我有两个esp32的开发板用于sdk里spi-slave的测试,
当我把发送端速度调到10M( .clock_speed_hz=10000000),收到的都是乱码;
当我把发送端速度调到8M(.clock_speed_hz=8000000),接受正常
spi的从端是否真能达到以上所说的20MHz(甚至是40MHz)?
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- Posts: 9709
- Joined: Thu Nov 26, 2015 4:08 am
Re: SPI slave mode (example)
Hard to say from wording like 'very messy'. Can you be more specific; what exactly do you send, what exactly do you receive? Do you have an oscilloscope trace of the signals on the line?
Re: SPI slave mode (example)
Hello!ESP_Sprite,
When I set .clock_speed_hz=8000000, the spi work well. But, when I set .clock_speed_hz=10000000, I receive wrong data as follow. Thanks!
When I set .clock_speed_hz=8000000, the spi work well. But, when I set .clock_speed_hz=10000000, I receive wrong data as follow. Thanks!
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- Posts: 9709
- Joined: Thu Nov 26, 2015 4:08 am
Re: SPI slave mode (example)
Any chance you can connect an oscilloscope to your signal lines? I'm thinking that stray capacitance or something may mess up your clock signal.
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Re: SPI slave mode (example)
LakshmiDhanaraj wrote:Hi,
I am using the SPI slaver driver example,sender as master and receiver as slave.I can able to transmit/receive data without dma.But it restricts the number of bytes to 32.For transmitting more than 32bytes,I am enabling the dma to 1,won't receive/transmits the data.Please help me out to solve this issue.What I have to change in the code for transmitting more than 32 bytes?
Can you please send the code, I am struggling with code.
Re: SPI slave mode (example)
Hi,
Has anyone been able to send more than 32 bytes?
I would like to send 20,000 bytes but not sure if it is possible as I was limited to 32 bytes using the spi slave library.
Thanks
Has anyone been able to send more than 32 bytes?
I would like to send 20,000 bytes but not sure if it is possible as I was limited to 32 bytes using the spi slave library.
Thanks
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