ADS1115 16-Bit ADC Modules and Arduino Interface Options

ADS1115 analog-to-digital conversion for Arduino and other controllers

Build an I2C analog-measurement path with an ADS1115 16-bit ADC board, a loose ADS1115 IC or a finished device that uses the converter internally. This collection includes blue, purple, red, mini, Raspberry Pi-oriented and connector-equipped modules; some product pages instead offer ADS1015, ADS1118, a PCA9306 I2C level translator, complete controllers or another converter. Check the actual selected model and quantity before treating a multi-model product heading as a component specification. “For Arduino” indicates an application category, not a promise that every selectable item contains a plug-and-play ADS1115 breakout or preconfigured software.

What an ADS1115 contributes to a measurement system

The ADS1115 digitizes analog voltage and communicates results over an I2C-compatible interface. Its input multiplexer permits four single-ended inputs referenced to ground or two differential input pairs, but the device performs conversions through one ADC path: “four channels” is not four independent simultaneous 860-samples-per-second ADCs. The programmable gain amplifier (PGA) selects full-scale differential ranges to better resolve an appropriately conditioned signal. The programmable data rate for an ADS1115 runs up to 860 samples per second according to several board descriptions; per-channel throughput and latency also depend on configuration, settling and I2C transactions. It is not a digital-to-analog converter, an analog amplifier that drives a load, or a voltage regulator despite miscellaneous generic catalog labels.

The ADS1115's nominal 16-bit output describes quantization, not a guaranteed 16-bit absolute measurement accuracy on any board. Sensor accuracy, divider ratio, reference and PGA behavior, offset, noise, input impedance, grounding, common-mode voltage, source impedance and conversion mode all matter. At a nominal ±2.048 V PGA span, 4.096 V divided by 65,536 is about 62.5 microvolts per output code; that arithmetic step is not the accuracy of a probe or the voltage that a pin may safely receive. Even if the PGA full-scale selection is larger than the supply, analog input pins must remain within their device-rated electrical limits. Consult the exact IC and board documentation before connecting a sensor or external power domain.

Choose the deliverable, not just the search phrase

• Populated ADS1115 I2C breakout: many offers select a single small board with VDD, GND, SDA, SCL, ADDR/ALRT and A0–A3 input connections, depending on the PCB. Other offers select 1, 2, 3, 5, 6, 10, 20 or 50 boards; blue, purple and red boards may be separate choices. A color does not guarantee the same pin header, pull-ups, footprint, connector or included cable across sellers. Some pages select “old version” versus “new version”; verify the revision-specific pin arrangement.
• STEMMA QT / Qwiic style breakout: several ADS1115 listings advertise compatible keyed I2C connectors, with separate 1, 2, 3, 5 or 10-piece choices. Check whether the selected board actually has that connector, its supply/pull-up domain and any cable inclusion. Matching connector shape does not establish safe 5 V operation on a 3.3 V host or automatic driver support.
• Loose ADS1115IDGSR / ADS1115IDGS chips: multiple listings select 2, 5, 10, 20, 50 or 100 pieces of small surface-mount ICs, with “BOGI/B0GI” printed-marking claims in some descriptions. These are components to assemble on a matching footprint, not Arduino-ready modules. Confirm exact suffix, marking, package drawing, condition and quantity for the selected offer; MSOP/VSSOP naming in seller titles is not a substitute for the manufacturer's land pattern.
• Specialized ADS1115 hardware: the KDT1115DAC-001 board appears with “Simple Driver Board,” “Old Version” and “ADS1115” options on one listing. Another KDT1115DAC-001 description specifies a 40 × 27 × 12 mm module, approximately 5 V supply and six-position interface, but also discusses a separate driver board and CH340/USART interface. Do not assume those driver-board connectors, protection features or firmware ship with the ADC-only selection. DFRobot Gravity and Raspberry Pi-targeted boards likewise have their own connector and supply arrangements.
• Finished measurement/control equipment: M5Stack Unit AMeter listings are current meters built around an ADS1115, not bare 4-channel voltage breakouts. One detailed AMeter listing describes an isolated interface, a ±4 A range, on-board fuse, factory calibration stored in EEPROM and a Grove cable. Those figures and isolation apply to that finished meter only; the ADS1115 alone cannot directly measure ±4 A. KinCony DM8 and B16 are complete ESP32-S3 controllers with analog inputs and separate dimmer or relay outputs. Their 12–24 V or 12 V supply, 0–5 V and 4–20 mA input circuitry, RS485, network, enclosure and outputs must never be attributed to a loose ADS1115 or basic module.

ADS1115 versus ADS1015, ADS1118 and other variants

ADS1115 is a 16-bit I2C ADC. ADS1015 is a 12-bit I2C ADC with a different resolution and rate envelope: several mixed board offers have both “ADS1115 blue/purple” and “ADS1015 blue/purple” choices. One page headed “ADS1115 & ADS1015 16-Bit” offers only an “ADS1015” variant, and its long description blends the two sets of specifications. That selected offer must be treated as ADS1015, not a 16-bit ADS1115. Another mixed offer labels “ADS1115” and “ADS1015” and also has cryptic numbered choices; where the numbered options do not establish the exact hardware, confirm with the product details rather than guessing.

ADS1118 is a different 16-bit ADC with an SPI digital interface and an internal temperature-sensing function; it is not a drop-in I2C ADS1115 board. Some listings combine ADS1115, ADS1015, ADS1118 and PCA9306 as variant options. PCA9306 is an I2C level translator, not an ADC: choosing its module or chip will not add an analog input. ADS1113 and ADS1114 are related ADC part numbers but should not be assumed to have the ADS1115's full input-multiplexer functions merely because a board description says “compatible.” A mixed IC listing specifically selects ADS1113IDGSR, ADS1114IDGSR, ADS1115IDGSR or ADS1118IDGSR; another selects ADS1013/1014/1015/1018, ADS8319, ADS8867 or ADS1118. Select the exact part, interface and footprint, not an umbrella claim that every choice is 16-bit I2C.

A large multi-option listing also offers ADS1115IDGSR loose ICs, ADS1015IDGSR, ADS1110, ADS1118, ADS1120, ADS1220, MCP3421, SGM58031, AD5593, PCF8591 and MCP4725 alongside ADS1115 boards. Its purple/blue board choices and 1/2/5/10-piece counts apply only to their corresponding variant. MCP4725 is a DAC, PCF8591 is an 8-bit ADC/DAC, and the other converters have their own bus protocols, resolutions, channel counts and pinouts. Generic statements about a 12-bit 3,300-SPS ADS1015 or a 24-bit ADS1220 do not describe an ADS1115. A separate mixed-chip product pairs ADS1115 with unrelated MCU, MOSFET, RS485 and power devices: a title listing all part numbers is not a mixed-component pack.

Addressing, wiring and input-domain decisions

For a typical ADS1115 module, inspect the actual board's supply and pin labels before connecting VDD/GND and the two I2C lines SDA/SCL to an appropriately configured controller. The ADS1115 supports four address selections determined by its ADDR pin connection; descriptions give common seven-bit addresses 0x48, 0x49, 0x4A and 0x4B for ADDR tied to GND, VDD, SDA and SCL respectively. That makes multiple separately addressed boards possible if the particular boards expose and wire ADDR correctly. Check bus pull-up resistors and their voltage domain on each board: joining several boards can produce excessive pull-up strength, and a 5 V bus is not automatically safe for a 3.3 V-only controller. A PCA9306 option is an interface component for appropriate level translation, not a universal cure for incorrect analog input voltage or grounding.

A0 through A3 are analog inputs; ALRT/RDY is a digital alert or conversion-ready function when supported and configured. Choose single-ended or differential measurement in firmware, select the PGA range to cover the expected differential signal, and account for allowable absolute input and common-mode voltage. Do not connect a bipolar external signal, mains conductor, current-loop wiring or high-voltage battery directly to a bare module just because a selected PGA range has a plus/minus sign. For 4–20 mA sensing, use an engineered current-sense circuit within rated input limits; the KinCony finished controller's conditioned 4–20 mA channels are not bare ADS1115 capabilities. Similarly, a finished ammeter's fuse and isolation do not extend to an unprotected breakout.

Sampling, resolution and software validation

1. Identify the actual silicon: inspect whether the chosen option says ADS1115, ADS1015, ADS1118, ADS1110 or another model. Select the matching Arduino/host driver and bus type. An ADS1118 SPI sketch cannot read an ADS1115 I2C device without adapting the architecture.
2. Match supply and logic: ADS1115 chip descriptions cite 2.0–5.5 V device operation, while individual boards can introduce regulators, pull-ups, LEDs or other restrictions. A “3.3 V for Raspberry Pi” board and a “3.3–5 V Gravity” board should be assessed separately. Verify the selected module's actual supply pin and controller I/O voltage.
3. Select channel mode and range: four single-ended inputs or two differential pairs are alternative MUX configurations; setting a gain does not turn the board into four synchronized converters. Compute expected sensor voltage under worst-case conditions and leave margin for reference, noise and overvoltage limits.
4. Specify rate realistically: 8–860 SPS is an ADS1115 programmable rate described on several listings, not a promise of 860 readings each second on each of four channels. High gain, switching channels, single-shot conversions and host bus latency affect usable throughput. ADS1015's faster headline rate must not be relabeled as ADS1115 performance.
5. Calibrate the whole chain: check offsets, reference behavior, sensor tolerance, filtering, wiring, ground return and repeatability at the expected operating temperature. “High precision,” “16-bit” and a small calculated LSB do not document an assembled measurement system's traceable accuracy or certification.
6. Confirm what arrives: inspect variant labels for model, PCB color or revision and 1/2/3/5/10/20/50/100-piece quantity. A 3D imaging layer-meter kit offers “ESP32” or “Atmega 328” variants with little detailed BOM; do not assume both processors, ADS1115 and every accessory ship together without item-specific confirmation.

This guide helps separate component-level ADS1115 purchasing from assembled Arduino-friendly development boards and integrated industrial or educational equipment. Preserve the distinction between device specification, seller's board claim and finished-system capability. No universal certification, chip provenance, interchangeability or ready-to-use software is implied for every listing; the selected product option and its current technical documentation govern the actual deliverable.