ADS1256: ads1256输入接地时显示为负值,在测试2.5v和3.3v电压时显示正常，为啥呢？求大佬解答

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在前面测试2.5v和3.3v是正常的，当测量接地时，会显示负值，而且每次接地时，负值都不一样。求大佬帮忙解惑。

(function(id, html, mimeType)
{
var v = document.getElementById(id + ‘_html5’),
checkVideo = function() {
if (!v.canPlayType || v.error || v.canPlayType(mimeType) == ”) {
var offset = 0;
while (v.childNodes.length > offset) {
if (v.childNodes[offset].nodeName != ‘SOURCE’) {
v.parentNode.insertBefore(v.childNodes[offset], v);
} else {
offset++;
}
}
v.parentNode.removeChild(v);
} else if (v.readyState == 0) {
window.setTimeout(checkVideo, 250);
}
};
document.getElementById(id + ‘_link’).onclick = function() {
document.getElementById(id).innerHTML = html;
return false;
};
window.setTimeout(checkVideo, 250);
})(‘video_f0477ce7-5521-4c41-bd3a-d2a00669664a’,’\r\n\u003cobject type=\”video/mp4\” data=\”https://e2echina.ti.com/cfs-filesystemfile/__key/communityserver-discussions-components-files/58/bandicam-2025_2D00_06_2D00_06-16_2D00_33_2D00_24_2D00_469.mp4?_=638848536870111120\” width=\”320\” height=\”240\”\u003e\r\n\t\u003cparam name=\”src\” value=\”https://e2echina.ti.com/cfs-filesystemfile/__key/communityserver-discussions-components-files/58/bandicam-2025_2D00_06_2D00_06-16_2D00_33_2D00_24_2D00_469.mp4?_=638848536870111120\” /\u003e\r\n\t\u003cparam name=\”url\” value=\”https://e2echina.ti.com/cfs-filesystemfile/__key/communityserver-discussions-components-files/58/bandicam-2025_2D00_06_2D00_06-16_2D00_33_2D00_24_2D00_469.mp4?_=638848536870111120\” /\u003e\r\n\t\u003cparam name=\”autostart\” value=\”true\” /\u003e\r\n\t\u003cparam name=\”autoplay\” value=\”true\” /\u003e\r\n\t\u003cparam name=\”enabled\” value=\”true\” /\u003e\r\n\t\u003cparam name=\”uiMode\” value=\”full\” /\u003e\r\n\t\u003cparam name=\”scale\” value=\”tofit\” /\u003e\r\n\t\u003cparam name=\”controller\” value=\”true\” /\u003e\r\n\t\u003cdiv class=\”message error\”\u003e此浏览器不支持此视频。\u003c/div\u003e\r\n\u003c/object\u003e’,’video/mp4′);

Eirwen：

已经收到了您的案例，调查需要些时间，感谢您的耐心等待。

,

Daniel：

您好

Blacky 说：当测量接地时

Can you clarify what it means "to measure grounding"? How are the signals applied to the ADC?

Can you also provide the register settings and a larger picture of the schematic (or just a PDF of the schematic)? I cannot make the image you provided bigger so the schematic is hard to read