Prototype 9.1

This basically Prototype 8 with minor bug fixes, higher amplification gain, an optional power LED, and easier assembly. See its description for more information.

Changes to Prototype 9:

• Increased amplification gain on electrode modules from x51 to x501. This increases the signal-to-noise ratio significantly.
• Reduced amplification gain of Signal 2 by half, compared to the other signals. (x251 compared to x501.) This compensates for a signal interference problem on the out2 trace of the electrode module PCB.

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• Bill of materials: bom_p9.1.ods
• Components:
• Power Module 4.1
• Electrode Module 3.1
• Circuit 10.2 (electrodes)
• Circuit 12 (power)
• AnalogToBLE 1.1 Firmware
• Python Library + GUI
• GNURadio Flowgraph for P10
• Date: 2022-02-01