Guide by Tim; Set Up a Geophone with a Raspberry Pi and an ADC (ADS1115)

Hi @Masoud264880 - welcome to the forums :slight_smile:
The ADS1115 ADC is a 4 channel amplifier. To use with a geophone requires 2x channels (to take a differential measurement)

That means each ADS1115 could support 2x geophones.
To add more geophones requires additional ADS1115 ADCs, which can be added to the same I2C bus by setting a new address. Each ADS1115 requires a unique address so the Pi can talk to it individually.

Soldering the A0 jumper will allow connecting a second ADC to the I2C bus (with address 0x49) for a maximum of 4x geophones.

Hi Tim, I am trying to install the packages using the scripts. They are not working. Is there an updated path for these?

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Hi Dylan,

Welcome to the forum! Can you please share what Pi you are using and what version of the OS you have. I know there’s some issues with pip on Bookworm so you may need to install Bullseye.

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Could this be adjusted to make a triaxial geophone? That would require 3 elements (2 horizontal SM-24) - can they be sourced?

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The python code has no waits or sleeps. When you read from i2c, does it wait for the next reading before continuing? ie its however-many samples per sec (Hz), so how do you ensure you read each sample and not double-read or miss a sample?

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Why do you say you need the 3V supply for the ADC,
when the webpage for that ADS1115 says it can accept " * Wide supply range: 2.0V to 5.5V"

?

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Hi Paul,

Welcome!

Unfortunately, we don’t have any suppliers currently stocking horizontal geophones - if you’re after a bulk QTY let us know!

I’m not too sure how Adafruit or Tim crafted the code for this one, in more modern drivers sometimes waits are added to ensure that data

Raspberry Pi’s operate on a logic level of 3.3V, the module has internal pull-up resistors to that supply voltage, so if a 5V supply was used the Pi would be damaged.

Liam

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