I2C做从机运行摄像头时，传输数据丢失的问题，串口响应延迟问题

element

I2C做从机运行摄像头时，传输数据丢失，I2C时钟频率115200，传输的是【1-10】10个数字，数据发送频率比较慢就手按触发的，接收数据
还时有丢失情况如下图，这是怎么回事呢：

代码如下：

from machine import I2C
import sensor,lcd,image,time
import KPU as kpu
receive_finish=0
receive_buf=[]

def on_receive(data):
    print("receive:",data)
    receive_buf.append(data)



def on_transmit():
    return 0

def on_event(event):
    global receive_finish
    #print("on_event:",event)
    if event==0:
        receive_finish = 0
    elif event==2:
        receive_finish = 1



i2c = I2C(I2C.I2C0, mode=I2C.MODE_SLAVE, scl=28, sda=29, addr=0x24, addr_size=7, on_receive=on_receive, on_transmit=on_transmit, on_event=on_event)
lcd.init(freq=15000000)
sensor.reset()
sensor.set_pixformat(sensor.RGB565)
sensor.set_framesize(sensor.QVGA)
sensor.set_vflip(0)
sensor.run(1)
while True:
    img=sensor.snapshot()
    if receive_finish and len(receive_buf):
        receive_finish = 0
        print("receive_buf",receive_buf)
        receive_buf=[]

另外用串口接收时，发命令给K210，串口中断直接回传，响应时间要半秒钟，有谁也出现这个问题啊，这么解决。而且串口初始化的TIME_OUT时间还得长些，不然会出问题，接收不到K210数据。

Neucrack

测试了一下，没有复现问题，请再测试一下，提供下复现代码，以下是测试代码：

固件版本：v0.5.0-45-g510c0c855

从机代码：

from machine import I2C

count = 0

def on_receive(data):
    print("on_receive:",data)

def on_transmit():
    global count
    count = count+1
    print("on_transmit, send:",count)
    return count

def on_event(event):
    if event != 0:
        print("on_event:",event)

i2c = I2C(I2C.I2C0, mode=I2C.MODE_SLAVE, scl=9, sda=10, addr=0x24, addr_size=7, on_receive=on_receive, on_transmit=on_transmit, on_event=on_event)

import sensor, image, time, lcd

lcd.init(freq=15000000)
sensor.reset()                      # Reset and initialize the sensor. It will
                                    # run automatically, call sensor.run(0) to stop
sensor.set_pixformat(sensor.RGB565) # Set pixel format to RGB565 (or GRAYSCALE)
sensor.set_framesize(sensor.QVGA)   # Set frame size to QVGA (320x240)
sensor.skip_frames(time = 2000)     # Wait for settings take effect.
sensor.set_jb_quality(95)
clock = time.clock()                # Create a clock object to track the FPS.

while(True):
    clock.tick()                    # Update the FPS clock.
    img = sensor.snapshot()         # Take a picture and return the image.
    lcd.display(img)                # Display on LCD
    print(clock.fps())              # Note: MaixPy's Cam runs about half as fast when connected
                                    # to the IDE. The FPS should increase once disconnected.

主机代码：

from machine import I2C
import time

i2c = I2C(I2C.I2C0, freq=100000, scl=9, sda=10)
devices = i2c.scan()
print(devices)

for device in devices:
    while 1:
        i2c.writeto(device, b'\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0A')
        time.sleep(1)

输出

on_receive: 1
on_receive: 2
on_event: 2
on_receive: 3
on_receive: 4
on_receive: 5
on_receive: 6
on_receive: 7
on_receive: 8
on_receive: 9
on_receive: 10
15.41198
15.50833
15.51247
15.50802
15.50388
15.50775
15.51139
15.38462
15.38462
15.46392
15.50388
15.47988
15.46392
15.48673
15.47389
15.46392
on_receive: 1
on_receive: 2
on_event: 2
on_receive: 3
on_receive: 4
on_receive: 5
on_receive: 6
on_receive: 7
on_receive: 8
on_receive: 9
on_receive: 10
15.45595
15.47117
15.46392
15.45779
15.45254
15.46392
15.45894
15.45455
15.45064
15.45972
15.45595
15.45254
15.44944
15.45699
15.45396
on_receive: 1
on_receive: 2
on_event: 2
on_receive: 3
on_receive: 4
on_receive: 5
on_receive: 6
on_receive: 7
on_receive: 8
on_receive: 9
on_receive: 10
15.32802
15.4486

element

Neucrack ![用你们的板子，你发的程序还是会有同样现象，接线如下，

Neucrack

同样的主机代码，使用你的从机代码输出也正常：


[MAIXPY]Pll0:freq:832000000
[MAIXPY]Pll1:freq:398666666
[MAIXPY]Pll2:freq:45066666
[MAIXPY]cpu:freq:416000000
[MAIXPY]kpu:freq:398666666
[MAIXPY]Flash:0xc8:0x17
open second core...
gc heap=0x800ecbd0-0x80237bd0(1355776)
[MaixPy] init end

 __  __              _____  __   __  _____   __     __
|  \/  |     /\     |_   _| \ \ / / |  __ \  \ \   / /
| \  / |    /  \      | |    \ V /  | |__) |  \ \_/ /
| |\/| |   / /\ \     | |     > <   |  ___/    \   /
| |  | |  / ____ \   _| |_   / . \  | |         | |
|_|  |_| /_/    \_\ |_____| /_/ \_\ |_|         |_|

Official Site : https://www.sipeed.com
Wiki          : https://maixpy.sipeed.com

MicroPython v0.5.0-45-g510c0c855-dirty on 2020-04-29; Sipeed
_M1 with kendryte-k210
Type "help()" for more information.
>>> 
paste mode; Ctrl-C to cancel, Ctrl-D to finish
=== from machine import I2C
=== import sensor,lcd,image,time
=== import KPU as kpu
=== receive_finish=0
=== receive_buf=[]
=== 
=== def on_receive(data):
===     print("receive:",data)
===     receive_buf.append(data)
=== 
=== 
=== 
=== def on_transmit():
===     return 0
=== 
=== def on_eent(event):
===     global receive_finish
===     #print("on_event:",event)
===     if event==0:
===         receive_finish = 0
===     elif event==2:
===         receive_finish = 1
=== 
=== 
=== 
=== i2c = I2C(I2C.I2C0, mode=I2C.MODE_SLAVE, scl=9, sda=10, 
addr=0x24, addr_size=7, on_receive=on_receive, on_transmit=o
n_transmit, on_event=on_event)
=== lcd.init(freq=15000000)
=== sensor.reset()
=== sensor.set_pixformat(sensor.RGB565)
=== sesor.set_framesize(sensor.QVGA)
=== sensor.set_vflip(0)
=== sensor.run(1)
=== while Tre:
===     img=sensor.snapshot()
===     if receive_finish and len(receive_buf):
===         receive_finish = 0
===         print("receive_buf",receive_buf)
===         receive_buf=[]
init i2c2
[MAIXPY]: find gc3028
True
True
receive: 1
receive: 2
receive: 3
receive: 4
receive: 5
receive: 6
receive: 7
receive: 8
receive: 9
receive: 10
receive_buf [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
receive: 1
receive: 2
receive: 3
receive: 4
receive: 5
receive: 6
receive: 7
receive: 8
receive: 9
receive: 10
receive_buf [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
receive: 1
receive: 2
receive: 3
receive: 4
receive: 5
receive: 6
receive: 7
receive: 8
receive: 9
receive: 10
receive_buf [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
receive: 1
receive: 2
receive: 3
receive: 4
receive: 5
receive: 6
receive: 7
receive: 8
receive: 9
receive: 10
receive_buf [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
receive: 1
receive: 2
receive: 3
receive: 4
receive: 5
receive: 6
receive: 7
receive: 8
receive: 9
receive: 10
receive_buf [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
receive: 1
receive: 2
receive: 3
receive: 4
receive: 5
receive: 6
receive: 7
receive: 8
receive: 9
receive: 10
receive_buf [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
receive: 1
receive: 2
receive: 3
receive: 4
receive: 5
receive: 6
receive: 7
receive: 8
receive: 9
receive: 10
receive_buf [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
receive: 1
receive: 2
receive: 3
receive: 4
receive: 5
receive: 6
receive: 7
receive: 8
receive: 9
receive: 10
receive_buf [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
receive: 1
receive: 2
receive: 3
receive: 4
receive: 5
receive: 6
receive: 7
receive: 8
receive: 9
receive: 10
receive_buf [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
receive: 1
receive: 2
receive: 3
receive: 4
receive: 5
receive: 6
receive: 7
receive: 8
receive: 9
receive: 10