Random Seeds and Random Numbers

Projects Programming
30

You're implying (or, I'm inferring) that the input impedance affects the response characteristics of the filtration. That makes sense to me, as the cap and the impedance of the op-amp together resemble a high-pass filter. Can I analyze that as simply a low-pass filter, followed by a high-pass? IOW, treat them separately, using f=1/(2piRC)?

I decided to go ahead and breadboard this, using on-hand parts. Oddly, that doesn't include any zeners, or 470pF caps. So I got a 3.9V zener from the landlord, and sorta randomly selected capacitors.

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This is a plot of the values on A0, measured every 1/2 second.

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The values:

113 119 064 041 034 044 071 083 079 056 042 047 072 089 089 069 052 051 070 091
094 081 060 057 070 095 103 083 064 063 079 104 107 077 066 072 097 113 105 074
070 085 108 116 088 075 077 100 121 107 081 080 098 120 123 093 083 087 111 128
113 087 089 109 131 123 093 091 105 134 131 100 095 114 140 132 101 100 132 144
121 101 113 143 144 112 104 132 149 136 110 115 145 151 126 112 129 151 147 120
116 144 157 140 120 127 156 160 135 123 140 162 158 130 126 152 165 151 128 131
161 166 142 127 141 167 164 136 129 154 171 157 132 134 164 172 147 132 146 172
170 141 135 161 175 160 137 142 172 176 150 138 157 178 170 143 142 170 180 157
141 153 179 177 149 144 169 183 167 144 151 181 183 157 146 167 188 177 150 149
179 188 166 148 160 188 187 157 150 177 193 177 153 160 190 194 166 157 180 198
186 161 164 194 199 173 161 180 201 193 166 166 195 204 179 168 187 214 200 163
154 206 214 165 138 151 200 189 131 133 202 205 160 130 161 228 211 132 144 224
231 174 140 172 245 229 142 152 235 242 183 144 167 241 225 141 150 228 237 182
142 170 248 230 139 149 242 246 186 141 166 250 236 139 148 220 194 185 161 165
196 202 171 154 181 200 188 161 164 197 200 172 162 185 204 191 164 171 202 205
175 163 186 206 192 164 165 197 202 173 159 178 201 192 161 163 194 202 177 160
180 206 199 168 168 200 209 181 153 198 238 209

// Checking out reading white noise

void setup()
{
  Serial.begin(9600);          //  setup serial
  analogReference(DEFAULT);
  delay (1000); // give me time to turn on the power supply.
}

void loop () {

  Serial.println(analogRead(0));
  delay (500);
}

At this point, I can just let it run for a bit and see what happens, but I wouldn't mind some feedback before I do that.