How does the ads1115 I2C external ADC work?
Introduction to ADS1115 External ADC ADS1115 is a 16-bit analog to digital converter that consists of four analog channels. It can be used in to measure both positive and negative voltages. It works in Single Ended, Differential and comparator mode. It works on I2C communication. It has a programmable comparator. It can be used in four modes.
How does ads1115 communicate with ESP32 pins?
As mentioned in previous sections, ADS1115 communicates data to ESP32 over I2C communication. We need to use I2C pins of ESP32 to read data. To handle communication and receive measured voltage over I2C, we can use ADS1115 library of Adafruit.
Why do we need to use external ADC with ESP32?
ADS1115 provides data over I2C communication. It consists of four analog channels. At the end of this guide, I will provide an example of analog voltage measurement with ADS1115 and ESP32. Why we need to use external ADC with ESP32?
What are the address of the ads1115 chips?
You can setup the ADS1115 with one of four addresses, so you can place 4 ADS1115 chips on a single I2C bus: 0x48, 0x49, 0x4a, 0x4b. The addressing control is unusual in that you only need to use one input pinas the address controlpin .
What kind of temperature sensor does ads1115 use?
LM35 temperature sensor gives output of 1mv per one degree centigrade of temperature. Built-in adc can not measure 1mV accurately and so is ESP32. ADS1115 is a 16-bit analog to digital converter that consists of four analog channels.
Why does an ADC need a reference voltage?
An ADC needs some kind of reference value because it outputs a number and that number is related to the value of the input. If the input voltage is 1.00 V but the ADC has no idea “how much” 1.00 V is then it cannot output the correct number. For that a reference voltage is needed. The supply could be used but sometimes the supply voltage varies.