24 bit AD
brain-duino 24 bit AD operation
24 bit AD board VS Arduino 10 bit AD.
8000 times more dynamic range, VS 10 bit AD.
25 times max input : +-2.5 mV max
320 times more low power calculation resolution.: 0.00059 µV
it is same noise as 10 bit version, but calculation resolution is 0.00059 µV
usually people mistake to understand this difference.
any case use with 24bit AD is more easy to setup at different condition and location.
specially noisy AC location is nice to use this. 25 times more AC noise effect rejection.
mean easy setup headset.
need to change brain-duino followings to connect 24 bit AD ADC7173 Breakout board.
next amp gain : X 250 to X 10 : R15 & R17 to 10 K ohm, R16 & R19 to 100 K ohm, C35 & C36 to 470 pF.
connect brain-duino amp output to ADC7173 BREAKOUT BOARD AIN0 .. AIN3 ( or AN 12 .. AN 15 as drawing )
only 2 ch 24 bit operation with Arduino UNO
ADC7173 BREAKOUT BOARD V1.0 connection to ICSP
PIN number is ADC7173 BREAKOUT BOARD
PIN 1 :
PIN 2 : AIN3 : GND
PIN 3 : AIN2 : A1
PIN 4 : AIN1 : GND
PIN 5 : AIN0 : A0
PIN 6 : MOSI : DOUT/RDY ICPS : 1 : MISO (IO12)
PIN 7 : MISO : DIN 3.3 V logic ICPS : 4 : MOSI (IO11)
PIN 8 : SCLK : SCLK 3.3 V logic ICPS : 3 : SCK (IO13)
PIN 9 : CS : CS 3.3 V logic : GND is select chip
PIN 10 : VDD1 : 5.5 V .. 28 V : set 2-3 for 3.3V & set 2-3 for 5 V
PIN 11 : VDD2
PIN 12 : GND: ICPS : 6 : GND
PIN 13 : AIN4 to PIN 24 : AIN15
https://github.com/brain-duino/AD7173
https://github.com/brain-duino/Arduino-Shield/tree/master/AD7173-Arduino-interrupt-test-with-IBVA
Raspberry pi doesn’t has AD input.
use this ADC7173 BREAKOUT BOARD with SPI connection is one of the way.
currently only 2 channel support with IBVA application.
also with Arduino UNO speed, max 2 channel operation.
more channel operation need to use high speed Arduino such as Arduino Zero, etc.
=============== VS with TI ads1299 =====================================
Use TI chip : ads1299 OpenBCI.com can make small size. use for multichannel is easy too.
few years ago i was thinking use same chip for 24 bit version IBVA.
but problem i found was TI chip amplifier is not so high quality low noise.
I think, for some purpose / for some people is ok to use TI chip.
followings are difference.
brain-duino 24 bit AD version ( 500 Hz sampling ) is :
10,000 times more high input impedance.
1/100 low input bias current.
max 2 K Hz sample 16 channel.
same as resistance noise when source impedance is 10 K to 30 M ohm
8nVrootHz (input v noise)
1fArootHz (input current noise)
Noise test, 10 bit AD, ADC7173 and ads1299
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question : contact@psychiclab.net
