FreeEEG32 alpha1.0 -- test failed, wired bug fixes

24 bits, 4kSPS, WIFI, Accel & hyro,
SD, Isolated SPI, UART, USB, power

Dmitry Sukhoruchkin

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Description

use new version: FreeEEG32 + alpha1.5 https://hackaday.io/project/166893-freeeeg32-alpha15,

Old version FreeEEG32 alpha1.0 -- alpha test failed, don't work without wired bug fixes,

32 channels mobile electroencephalography under GNU AGPL,

Sources https://github.com/neuroidss/FreeEEG32-alpha1.0,

Estimation on components https://docs.google.com/spreadsheets/d/1I1SXv34KVm8_NiMJIa0ackJ7CWcz8a3qzO6xP9ym8yQ

Details

ESP8266 not worked in this configuration, because it radiates on nearby channels.

Data and power over USB only working good when clean power -- from OrangePi for example, another way there will be noise from USB line.

So better separate power from USB, what was before USB and ESP8266 was added in last moment and not tested.

So in FreeEEG32 alpha1.05 made changes that ESP8266 module was excluded, and UART isolator was not used, and only used power isolator for power supply from battery.

And SPI isolator was fixed so it can pass UART, so this isolated UART used to connect to external ESP32 devboard, to be used as USB when ESP32 disabled, or can be used as WiFi.

New changes will be tested in FreeEEG32 prealpha2 https://hackaday.io/project/165748-freeeeg32-prealpha2

Made FreeEEG32+ alpha1.5 https://hackaday.io/project/166893-freeeeg32-alpha15 with all bug fixes that was found in alpha1 test.

Files

FreeEEG32.ods BOM spreadsheet - 86.69 kB - 04/18/2017 at 08:09		Download
gerber.zip gerber Zip Archive - 165.03 kB - 04/15/2017 at 21:37		Download

Components

4 × AD7770ACPZ 8-Channel, 24-Bit Simultaneous Sampling ADC
4 × ADR4525BRZ Power Management ICs / Voltage References
1 × DA2303-ALD Inductors, Chokes, Coils and Magnetics / Current, Voltage and Power Transformers
2 × MBR0520LT1G Discrete Semiconductors / Diodes and Rectifiers
1 × ISO7341CDW Robust EMC, Low Power, Quad-Channel 3/1 Digital Isolator, Fail-Safe High