求教。。

3homer · 发表于 2007-12-5 20:00:29

I checked the I2C waveforms. I can see the address byte(0x20) being sent. But the ACK bit is high(If the sensor is good and has matching address, it should pull ACK low). So this means no reply. I also tested with address 0x30 with the same result. I checked the power, reset, camera_en, etc, and they seem to be correct.
I have attacked a test program. If the I2C works, it will output "success" in \msg.txt. You may also use it to check the I2C waveforms on osciloscope(you may show I2C_SDA and I2C_CLK at the same time, and looking at I2C_SDA values at rising edge of I2C_CLK, it should be the slave address followed by ACK bit). I don't know why the I2C waveform seems correct but there is no ACK. The only problem I can think of is the sensors are damaged. Please have a test. Please also check if power, reset, camera_en are correct. Thank you.

由于一些特别原因，我没有直接和客户接触，所以就是这么多反馈，我第一感觉是初始的code可能有问题。Sensor是MT9D112

coma · 发表于 2007-12-6 11:41:37

I2C address is wrong?

KING11 · 发表于 2007-12-6 13:46:33

楼上的正解。应答位没有是因为IIC的读写地址没有设好的原因。

检查一下MT9D112的IIC的读写地址是多少，跟客户沟通一下，看他们那边设的是多少？

[em01]

3homer · 发表于 2007-12-7 16:06:05

MT9D112的是0x20写0x21读,没错啊还有别的原因么大家帮忙一下我这边也没什么实物好搞..

fredo · 发表于 2007-12-9 14:25:53

不会的，MT9D112的ID应该是 R0X0019和R0X003B，不会是0X20和0X21，CHECK一下。

3homer · 发表于 2007-12-9 21:56:43

[upload=jpg]UploadFile/2007-12/07129@52RD_0.JPG[/upload]

fredo · 发表于 2007-12-10 13:34:34

write address use 0x78 & read address use 0x79,try this good luck![em01][em01]

KING11 · 发表于 2007-12-10 16:23:22

[upload=jpg]UploadFile/2007-12/071210@52RD_2.jpg[/upload]

呵呵在多试一试
如图地址[br]<p align=right><font color=red>+3 RD币</font></p>

francisli · 发表于 2007-12-10 22:13:11

建议检查一下Sensor初始化的Rset\Power Down\AVDD/DVDD/DOVDD等顺序是否正确.

3homer · 发表于 2007-12-21 13:17:12

客户说I2C address 0x7A有response
请问各位具体是那个呢？？

ly8211 · 发表于 2007-12-21 14:08:42

Bits [7:1] of this byte represent the device slave address and bit [0] indicates the data
transfer direction. A “0” in bit [0] indicates a write, and a “1” indicates a read. The default
slave addresses used by the MT9D112 are 0x78 (write address) and 0x79 (read address[/COLOR]).
Alternate slave addresses of 0x7A (write address) and 0x7B (read address) can be
selected by asserting the SADDR input signal.

3homer · 发表于 2007-12-21 20:19:17

To King11
你的MT9D112的datasheet 是哪个版本请给我一下，谢谢。。

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