ADC Expansion
The ADC Expansion allows you to read analog signals up to 5V with your Omega2. Now you have an opportunity to convert analog signal such as sound, temperature, humidity and others into a digital signal. It has 4 analog input channels, 16 BIts of precision and up to 860 samples per second. The expansion also communicates with the Omega over I2C.
The Hardware
The ADC Expansion features the following:
- 4 analog input channels and provides 5V and GND female headers for each of the 4 inputs
- provides 5V and GND female headers for each of the 4 inputs
- An address switch
- 3x Grove connectors
The ADC Expansion is based on the TI ADS1115 analog-to-digital converter chip.
Connecting to a Dock
To use the ADC Expansion, plug it into a Dock that has Expansion header pins (Expansion Dock, Power Dock 2, Arduino Dock R2).
The ADC Expansion is stackable! Each Omega2 can support up to 2 stacked ADC Expansions, giving you 8 analog input channels in total. Just be mindful of wires that are connected to the bottom Expansion.
Analog Input Headers
A female header provides access to all 4 analog input channels, making analog input plug and play.
5V and GND female headers are also provided for each of the 4 inputs, to make powering the analog sensor easier.
Grove Connectors
The ADC expansion includes 3 grove connectors, 2x analog, 1x digital (I2C) allowing you to easily connect any Grove sensors and peripherals.
The digital Grove connector is connected to the Omega’s I2C bus. Since I2C is a bus, it’s acceptable, and in fact, intended, that many I2C devices are connected to the bus. So it’s alright to have an I2C Grove peripheral connected as well as other I2C devices.
IMPORTANT NOTE: Only a single input is allowed for each channel. If a Grove peripheral is connected and occupying an analog input channel, you CANNOT “re-use” the input channel by connecting a different input signal to the female header. This can lead to damage of the ADC Expansion, the connected Omega, or both.
The Address Switch
The address switch changes the I2C device address of the ADC Expansion, allowing users to use two ADC Expansions with a single Omega, providing EIGHT analog input channels
The switch changes the I2C address of the ADC chip on the ADC Expansion. That way, two ADC Expansions can be included on the Omega’s I2C bus
| Switch Position | I2C Device Address |
|---|---|
| 0x48 (Farther from Expansion Header) | 0x48 |
| 0x49 (Closer to Expansion Header) | 0x49 |
Using the ADC Expansion
Read our guide to using the ADC Expansion to learn how to read analog voltages from the command line.