Part Number:DLPC3479Other Parts Discussed in Thread:DLPA3005, DLP4710,
现象如题,固件版本8.1.1,GUI软件版本3.1.0.5;
多次尝试复现的时间不固定,一般2小时以上;
复现问题时,i2c接口可以正常读写,比如读取dmd type,发送投图start指令也会成功,但实际上没有投光;
使用TI的上位机软件DLP EVM GUI 3.1.0.5也可以连接上,没有报Error,此时使用Test Patterns有时候可以投光,但不一定;
复现时,硬件状态:
DLPA3005的SEL0和SEL1都是低电平;
DLPA3005的VOFS、VBIAS、VRST测量电压分别是10V,18V,-14V
Flash的clk和data引脚没有任何信号跳变;
另外,仅使用TI的软件DLP EVM GUI 3.1.0.5,进行连续的投图测试,没有复现类似的情况;
想问一下
1.这可能是哪个模块的问题?硬件还是软件
2.看到别的问答有提到温度保护,但在手册上只找到了芯片运行的环境温度范围,没有提到触发温度保护的具体值?
Sophie Chen:
如果使用GUI软件没有复现到问题,可以检查一下自己的程序是否频率设置,曝光时间设置的不合适,参考programmer guide
,
MA QING YUAN MA:
你好!感谢回复。
我还是这个问题的提问者,原账号登录有某些问题,因此换这个账号继续沟通;
问题:
1.目前项目采用的曝光时间exposure,是通过TI的api返回推荐的最小 pre post exposure进行设置的,我可以认为这种方式设置的曝光时间是可靠的吗?
2.回复提到的频率设置指的是什么?
3.我们在DLPC3479+DLPA3005+DLP4710的手册中未发现触发过温保护相关信息,请问能确认一下这3款芯片是否有过温保护机制吗?如果有那么触发阈值是多少?
希望工程师可以逐个回复,非常感谢!
,
Jeremy_Wu:
1. 一般是根据选择的软件配置:
https://software-dl.ti.com/dlp/pico-fw-selector/
来确定最小曝光时间:
Internal Pattern Mode Timings:
Pattern Type
Sequence Index
Exposure Time Range (us)
Sequence Min Pre-Exposure Dark Time (us)
Sequence Min Post-Exposure Dark Time (us)1-bit Monochrome
18
200 – 399
171
3117
400 – 799
171
3116
800 – 799
171
3115
1800 – 3799
171
3114
3800 – 7600
171
311-bit RGB
25
600 – 1799
171
3124
1800 – 3799
171
3123
3800 – 7600
171
318-bit Monochrome
20
2084 – 4168
171
3121*
1677 – 2083
171
318-bit RGB
22
6512 – 13024
171
31*Sequence 21 is a special sequence that displays 7-bit patterns. The least significant bit of the 8-bit pattern data will be ignored.
Notes:
For internal patterns, there will be an additional variable delay of ~3000 us at the beginning of every pattern set.
Exposure times shorter than the above values are not possible. Longer exposure times will operate with decreased timing accuracy and behavior is not guaranteed.
Shorter dark times are not possible. Longer dark times can be used. The maximum possible dark times for a desired exposure time are:Tmax pre-exposure dark time = ( 27306us + tsequence min pre-exposure dark time ) * (Tdesired exposure / tsequence minimum exposure)
Tmax post-exposure dark time = ( 27306us + tsequence min post-exposure dark time ) * (Tdesired exposure / tsequence minimum exposure)External Pattern Streaming Timings:
Pattern Type
Sequence Index
Exposure Time Range (us)
Sequence Min Pre-Exposure Dark Time (us)
Sequence Min Post-Exposure Dark Time (us)1-bit Monochrome
6
200 – 400
0*
0*5
200 – 399
171
314
400 – 799
171
313
800 – 1799
171
312
1800 – 3799
171
311
3800 – 7600
171
311-bit RGB
11
451 – 799
171
3110
800 – 1799
171
319
1800 – 3799
171
318
3800 – 7600
171
318-bit Monochrome
7
2555 – 5110
171
318-bit RGB
0
10912 – 21824
171
31和公式:
Exposure times shorter than the above values are not possible. Longer exposure times will operate with decreased timing accuracy and behavior is not guaranteed.
Shorter dark times are not possible. Longer dark times can be used. The maximum possible dark times for a desired exposure time are:Tmax pre-exposure dark time = ( 6553us + tsequence min pre-exposure dark time ) * (Tdesired exposure / tsequence minimum exposure)
Tmax post-exposure dark time = ( 6553us + tsequence min post-exposure dark time ) * (Tdesired exposure / tsequence minimum exposure)https://software-dl.ti.com/dlp/pico-fw-selector/release_notes/FWSel_DLPC3479_DLPA3005_pm2_i2c0x36_v8p1p1.html
2. 频率就是曝光时间的倒数。
3. 温度保护看您的硬件设计,TI EVM板有热敏电阻,可以读取温度数据,这样你前面MCU可以根据温度保护。
另外3005内部有温度保护。