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TinyCircuits Products => Wirelings => Topic started by: 66hades on August 25, 2020, 06:38:20 PM

Title: Multiple Soil Moisture Sensor Wireling AST1037 Sensors
Post by: 66hades on August 25, 2020, 06:38:20 PM
Hello,
The AST1037 moisture/temp sensor communicates over I2C. That means you can connect multiple of these sensors to the same I2C bus and address them individually? Or do they all share the same address?
Thanks, 66hades
Title: Re: Multiple Soil Moisture Sensor Wireling AST1037 Sensors
Post by: lennevia on August 26, 2020, 01:09:59 PM
Hello,

The Moisture Sensor Wirelings all have the same I2C address, I believe it is 0x30 - it is common for many I2C devices to have the same address amongst their copies.

To individually address each sensor, you would ideally want a multiplexer to be able to switch between different sensors with the same address. Our Wireling Adapter TinyShield, RobotZero, Wireling Pi Hat, and Arduino Wireling Shield all have a PCA9544 multiplexer (at address 0x70) for this reason. (The WirelingZero is a little different hardware-wise)

On top of the four ports available in a single Wireling Adapter TinyShield (that you can stack on any of our processor boards: TinyScreen+, TinyZero, TinyDuino) or RobotZero, you can add up to 7 more Wireling Adapter TinyShields while changing the address resistors (https://learn.tinycircuits.com/Wirelings/Wireling-Adapter_TinyShield_Tutorial/#adding-more-wireling-tinyshields) (0x70-0x77) for a total of 8 boards, meaning a total of 32 possible wirelings per processor.

I hope that answers your question and gives you a little background on how we get around address conflict with I2C devices!

Thanks,
Réna