Part Number:ADS1299
上图可以看到输出信号中ch1,2,3,4的噪声从小变大,而且不一致,感觉不像是电源噪声
设备是自己做的
一部分寄存器信息
ADS1299 ID = 111100
CONFIG1 = 11110101
CONFIG2 = 11000000
CONFIG3 = 11101100
LOFF_SENSP = 0
LOFF_SENSN = 0
LOFF_STATP = 0
LOFF_STATN = 0
BIAS_SENSN = 1111
BIAS_SENSP = 1111
CH1SET = 1100001
CH2SET = 1100001
CH3SET = 1100001
CH4SET = 1100001(4个通道的配置一模一样,但是ch1噪声偏少,ch4最多)
Amy Luo:
您好,
您将每个通道的CHnSET最高位都设置为1了,即power down了,在这种情况下应该不进行ADC转换了,DOUT上还有输出吗?您可以用示波器实测一下这种情况下的DOUT的波形吗?看下上面是否有数字信号?
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Aknife:
不好意思,实际上寄存器里的内容应该是,高位的0没有打印出来
ADS1299 ID = 00111100CONFIG1 = 11110101CONFIG2 = 11000000CONFIG3 = 11101100LOFF_SENSP = 00000000LOFF_SENSN = 00000000LOFF_STATP = 00000000LOFF_STATN = 00000000BIAS_SENSN = 00001111BIAS_SENSP = 10000111CH1SET = 01100001CH2SET = 01100001CH3SET = 01100001CH4SET = 01100001(4个通道的配置一模一样,但是ch1噪声偏少,ch4最多)
DOUT的输出我用Python画成上边的图了,有很多椒盐脉冲噪声
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Aknife:
我刚刚发现我的4pag芯片其他通道也有读数
开头24bit+后边8个通道的读数:
110000000000000000000000,FFFC01,FFFB09,FFFB9F,FFFB98,C00000,FFFC01,FFFB9F,FFFB9F110000000000000000000000,FFFC05,FFFB0E,FFFBA3,FFFB9A,C00000,FFFC05,7FFE0,7FFE0110000000000000000000000,FFFC03,FFFB06,FFC000,FFFC,5FFFB,DFFFB,97C000,97C000110000000000000000000000,FFFC07,FFFB0F,FFFB9F,FFFB99,C00000,FFFC07,FFFB9F,FFFB9F110000000000000000000000,FFFC08,FFFB0D,FFFBA2,FFFB99,C00000,FFFC08,FFFBA2,FFFBA2110000000000000000000000,FFFC03,FFFB0E,FFFB9E,C00000,FFFC05,FFFB0C,FFFB99,FFFB99110000000000000000000000,FFFC06,FFFB10,FFFBA5,FFFB9E,C00000,FFFC06,FFFBA5,FFFBA5110000000000000000000000,FFFC02,FFFB0F,FFFBA1,FFFB9B,C00000,FFFC02,FFFBA1,FFFBA1110000000000000000000000,FFFC07,FFFB0E,FFFBA3,FFFB9E,C00000,FFFC07,FFFBA3,FFFBA3110000000000000000000000,FFFC06,FFFB0C,FFFBA4,FFFB9A,C00000,FFFC06,FFFBA4,FFFBA4110000000000000000000000,FFFC08,FFFB10,FFFBA3,FFFB9C,C00000,FFFC08,FFFBA3,FFFBA3
刚刚发现开头的24bit会变的(CHnSET最高位都设置为1的结果)
110000000000000000000000,0,0,0,0,C00000,0,0,0110001111000000000000000,0,0,0,0,18000,0,0,0110000000000000000000000,0,0,0,C00000,0,0,0,0110000000000000000000000,0,0,0,0,C00000,0,0,0110000000000000000000000,0,0,0,0,C00000,0,0,0110000000000000000000000,0,0,0,0,C00000,0,0,0111110000000000000000000,0,0,0,0,180000,0,0,0
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Amy Luo:
根据数据表如下截图所描述,输出8通道应该是正常的,但是后面4通道应该是0才对:
关于开头的24bit,1100不应该变,后面的 LOFF_STATP + LOFF_STATN 可以不用管它,因为在您的配置中LOFF_SENSP 和 LOFF_SENSN都是Disabled的;
您可以附上您读取数据时的SPI示波器波形吗?
另外,是否验证了寄存器写入后可以正确读出?
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Amy Luo:
抱歉,我上面回复错了,对于ADS1299-4 输出应该是(24 status bits + 24 bits × 4 channels) = 120 bits,这样才对,我不确定您的为什么输出8通道的数据,您可以确定一下您读出的ID值是00111100 吗?
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Aknife:
我没有示波器,我很抱歉
但我能确定ID是00111100,毕竟我买的就是这个4PAG芯片,ADS1299-x的输出统一是216bits,读取4通道还是8通道都一样的,只不过后边都是0,我读取其他通道主要是为了看看可能是啥问题
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Amy Luo:
感谢反馈,我还是想确认下寄存器是否已验证了可以正确读写,以及读取AD转换结果时的SPI(DRDY、CS、SCLK、DOUT)的示波器波形
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Aknife:
泪目调好了,抄了一遍OpenBCI cyton的配置,但是到底啥情况导致的还不清楚
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Aknife:
新配置,是不是以前信息增益设的低了
ADS1299 ID = 00111100CONFIG1 = 10010110CONFIG2 = 11000000CONFIG3 = 11101100LOFF_SENSP = 0LOFF_SENSN = 0LOFF_STATP = 0LOFF_STATN = 0BIAS_SENSN = 00001111BIAS_SENSP = 00001111CH1SET = 01101000CH2SET = 01101000CH3SET = 01101000CH4SET = 01101000
不过还有个问题是是不是的有点脉冲