ADS1115 Lower Counts than Expected

Other Hardware 3rd Party Boards
1

I bought a ADS1115 board (16 bit version) from Amazon recently (Amazon.com: HiLetgo 3pcs ADS1115 16 Bit 16 Byte 4 Channel I2C IIC Analog-to-Digital ADC PGA Converter with Programmable Gain Amplifier High Precision ADC Converter Development Board for Arduino Raspberry Pi : Industrial & Scientific). It seems to work fine in differential and single sided mode and it has almost no noise. However, the maximum values which it can output is 2047 which is a 11 bit number. I am using the Adafruit ADS1X15. I am powering the board though the 5V and gnd on the Arduino uno, SCL is connected to A5 and SDA is connected to A4. The signal wire from a potentiate is connected to A0. Also, in the code I am declaring the read value as a 16 bit integer.

I think this could be due something within the library or possibly my board is a fake. Please let me know!

Code: ADS1115Speed.ino (958 Bytes)

.h file: Adafruit_ADS1X15.h (8.6 KB)

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Adafruit_ADS1015 ads1115;

You're declaring instance as a 12bit product...
Also, get 11bit positive value because is 12bit including the negative part in the differential.

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Awesome! Thanks a ton for the speedy response. The code works great now by using "Adafruit_ADS1115 ads1115;"

Also, I know this dosent really belong here but I wanted to see if someone has an opinion on small voltage readings (~5mV) and using a high resolution adc or an opamp and a normal adc, or a combination I guess like the ADS1115 is (but preferably I would have a larger range of the gains).

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First of all, it is bit difficult to getting microvolt resolution correctly with hobbyists project due to problems such as noise.
If still try it, I think put a pre-amplifier right after the sensor output for noise prevention.
Of course this is my idea and not everyone else does.
The analog circuit is very very mystic and fantastic.

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Thanks for your input

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