# Title The Maker's Guide to ADCs: Resolution, Speed, and Interface Compared Compare analogue-to-digital converters by bit depth, sample rate, and bus (I²C vs SPI) to pick the right chip for your Arduino, Raspberry Pi, or microcontroller project. _Updated 2026-05-18 · Reviewed by Marcus Schappi, Co-founder, Little Bird Electronics._ URL: https://littlebirdelectronics.com.au/guides/makers-guide-to-adcs --- External analogue-to-digital converters, or ADCs, are one of the easiest ways to improve sensor reading quality in an Arduino, Raspberry Pi or other microcontroller project. They let you add more analogue inputs, increase resolution beyond what your board offers on-board, or handle specialised jobs such as reading load cells and other very small differential signals. In this guide, we compare popular ADC breakout boards by the specs that matter most to makers: bit depth, channel count, interface, and intended use. We also cover when I_2_C is the simpler choice, when SPI or other interfaces make more sense, and which boards are better suited to general sensing versus precision measurement. For AU makers, these breakout-style modules are also practical because they are easy to prototype, breadboard and integrate without long lead times. **Quick comparison snapshot:** - **For general-purpose projects:** ADS1115 and ADS1015 are the most straightforward picks. - **For lots of analogue inputs:** ADS7830 gives you 8 channels over I_2_C. - **For precision differential measurement:** MCP3421, MCP3424 and ADS122C04 focus on higher resolution. - **For load cells and strain gauges:** HX711 and NAU7802 are purpose-built options. - **For PC-connected workflows:** MCP2221A is different again, acting as a USB bridge with built-in ADC inputs. ## Our picks - **ADS7830 8-Channel 8-Bit I2C ADC Breakout** — Best for many analogue inputs — https://littlebirdelectronics.com.au/products/adafruit-ads7830-8-channel-8-bit-adc-with-i2c - **MCP3421 18-Bit ADC Breakout - STEMMA QT / Qwiic** — Best for single-channel precision — https://littlebirdelectronics.com.au/products/adafruit-mcp3421-18-bit-adc-stemma-qt-qwiic - **Adafruit MCP2221A Breakout - General Purpose USB to GPIO ADC I2C - Stemma QT / Qwiic** — Best for USB-connected projects — https://littlebirdelectronics.com.au/products/adafruit-mcp2221a-breakout-general-purpose-usb-to-gpio-adc-i2c-stemma-qt-qwiic - **Adafruit NAU7802 24-Bit ADC - STEMMA QT / Qwiic** — Best load-cell ADC over I2C — https://littlebirdelectronics.com.au/products/adafruit-nau7802-24-bit-adc-stemma-qt-qwiic - **Adafruit HX711 24-bit ADC for Load Cells / Strain Gauges** — Best for load cells — https://littlebirdelectronics.com.au/products/adafruit-hx711-24-bit-adc-for-load-cells-strain-gauges-ada5974 - **MCP3424 18-Bit ADC-4 Channel with Programmable Gain Amplifier** — Best for multi-channel precision over I2C — https://littlebirdelectronics.com.au/products/mcp3424-18-bit-adc-4-channel-with-programmable-gain-amplifier - **ADS1015 12-Bit ADC - 4 Channel with Programmable Gain Amplifier** — Best for faster general sensing — https://littlebirdelectronics.com.au/products/ads1015-12-bit-adc-4-channel-with-programmable-gain-amplifier - **ADS1115 16-Bit ADC - 4 Channel with Programmable Gain Amplifier** — Best overall — https://littlebirdelectronics.com.au/products/ads1115-16-bit-adc-4-channel-with-programmable-gain-amplifier - **ADS122C04 24-Bit 4-Channel I2C ADC Breakout** — Best high-resolution general ADC — https://littlebirdelectronics.com.au/products/adafruit-ads122c04-24-bit-adc-4-channel-2-ksps - **10-bit ADC (SPI) - 4 Channel** — Budget SPI ADC — https://littlebirdelectronics.com.au/products/10-bit-adc-spi-4-channel - **10-bit ADC (SPI) - 8 Channel** — Best low-cost SPI option — https://littlebirdelectronics.com.au/products/10-bit-adc-spi-8-channel - **SparkFun Qwiic 12 Bit ADC - 4 Channel (ADS1015)** — Best Qwiic general sensing — https://littlebirdelectronics.com.au/products/sparkfun-qwiic-12-bit-adc-4-channel-ads1015 - **MCP3008 - 8-Channel 10-Bit ADC With SPI Interface** — https://littlebirdelectronics.com.au/products/mcp3008-8-channel-10-bit-adc-with-spi-interface - **Gravity: 0-10V 15-bit High-Precision Dual-Channel ADC Module** — https://littlebirdelectronics.com.au/products/gravity-0-10v-15-bit-high-precision-dual-channel-adc-module - **Adafruit PCF8591 Quad 8-bit ADC + 8-bit DAC - STEMMA QT / Qwiic** — Best ADC/DAC combo — https://littlebirdelectronics.com.au/products/adafruit-pcf8591-quad-8-bit-adc-8-bit-dac-stemma-qt-qwiic - **Gravity: I2C ADS1115 16-Bit ADC Module (Arduino Raspberry Pi Compatible)** — Best for Gravity sensor projects — https://littlebirdelectronics.com.au/products/gravity-i2c-ads1115-16-bit-adc-module-arduino-raspberry-pi-compatible --- ## ADS7830 8-Channel 8-Bit I2C ADC Breakout _Best for many analogue inputs_ **Price:** $14.20 · **Stock:** Out of stock **Product page:** https://littlebirdelectronics.com.au/products/adafruit-ads7830-8-channel-8-bit-adc-with-i2c The ADS7830 is aimed at projects where channel count matters more than fine resolution. With 8 analogue inputs over I_2_C, it is a practical way to add basic sensor reading to a Raspberry Pi or expand a microcontroller that has run out of ADC pins. Its 8-bit resolution is the main trade-off, so it suits knobs, LDRs, flex sensors and other simple inputs better than precision measurement. If you need cleaner gradation or small-signal work, the 12-bit, 16-bit and higher-resolution options below are more suitable. **Key specs:** - **Device type:** General-purpose ADC breakout - **Resolution:** 8-bit - **Channels:** 8 - **Interface:** I2C - **Operating voltage:** 2.7V to 5.25V **Pros:** - 8 analogue input channels on one board - Simple I2C connection - Useful for Raspberry Pi projects without built-in analogue input - STEMMA QT / Qwiic ecosystem support **Cons:** - 8-bit resolution is limited for precision sensing - Better suited to simple sensors than low-level measurement --- ## MCP3421 18-Bit ADC Breakout - STEMMA QT / Qwiic _Best for single-channel precision_ **Price:** $14.20 · **Stock:** Available (supplier stock) **Product page:** https://littlebirdelectronics.com.au/products/adafruit-mcp3421-18-bit-adc-stemma-qt-qwiic The MCP3421 takes the opposite approach to multi-channel ADCs: it focuses on one high-resolution differential input instead of trying to do everything. That makes it a good fit for precision sensing where channel count is less important than extracting small changes cleanly. Because it includes adjustable gain and a built-in precision reference voltage, it is more specialised than an ADS1015 or ADS1115. If you only need one channel and your signal is small, it is a more targeted option than a general-purpose ADC breakout. **Key specs:** - **Device type:** Precision differential ADC breakout - **Resolution:** 18-bit - **Channels:** 1 - **Interface:** I2C **Pros:** - 18-bit resolution for finer measurement - Differential input suits small signals - Built-in precision reference voltage - Adjustable gain - Easy I2C integration with STEMMA QT / Qwiic **Cons:** - Only 1 channel - Less versatile for multi-sensor projects --- ## Adafruit MCP2221A Breakout - General Purpose USB to GPIO ADC I2C - Stemma QT / Qwiic _Best for USB-connected projects_ **Price:** $12.68 · **Stock:** In stock **Product page:** https://littlebirdelectronics.com.au/products/adafruit-mcp2221a-breakout-general-purpose-usb-to-gpio-adc-i2c-stemma-qt-qwiic The MCP2221A is not a normal external ADC breakout in the same mould as the others here. Its main role is bridging a computer to I_2_C and GPIO over USB, with built-in 10-bit ADC inputs as part of that broader feature set. That makes it interesting for Python-on-PC workflows, lab setups or quick sensor experiments without a separate microcontroller. As a pure ADC choice, though, it is less direct than the dedicated converter boards in this comparison. **Key specs:** - **Device type:** USB bridge with ADC inputs - **Resolution:** 10-bit - **Interface:** USB, I2C / STEMMA QT, Analog, GPIO - **Operating voltage:** 3.3V / 5V **Pros:** - Works directly with a computer over USB - Includes built-in ADC capability - Also provides USB-to-I2C and GPIO functions - Breadboard-friendly and suitable for quick prototyping **Cons:** - Not a dedicated general-purpose ADC board - 10-bit ADC resolution is modest --- ## Adafruit NAU7802 24-Bit ADC - STEMMA QT / Qwiic _Best load-cell ADC over I2C_ **Price:** $12.30 · **Stock:** Available (supplier stock) **Product page:** https://littlebirdelectronics.com.au/products/adafruit-nau7802-24-bit-adc-stemma-qt-qwiic The NAU7802 is built specifically for strain gauges, load cells and Wheatstone bridge sensors, rather than being a general sensor ADC. Its 24-bit resolution, differential design and built-in gain and calibration features make it a strong match for scales and force-measurement projects. Compared with a generic ADC, it is far better aligned to tiny bridge-sensor signals. If your project is weight or force measurement and you prefer I_2_C wiring, this is one of the most targeted options in the group. **Key specs:** - **Device type:** Load-cell / bridge-sensor ADC breakout - **Resolution:** 24-bit - **Interface:** I2C / STEMMA QT - **Operating voltage:** 3.3V / 5V **Pros:** - Designed specifically for load cells and strain gauges - 24-bit resolution - Built-in gain amplification and calibration circuitry - I2C interface is simple to wire - Includes screw terminals for sensor connection **Cons:** - Not intended as a general-purpose multi-sensor ADC - Application is narrow compared with ADS1115-style boards --- ## Adafruit HX711 24-bit ADC for Load Cells / Strain Gauges _Best for load cells_ **Price:** $19.28 · **Stock:** Available (supplier stock) **Product page:** https://littlebirdelectronics.com.au/products/adafruit-hx711-24-bit-adc-for-load-cells-strain-gauges-ada5974 The HX711 is one of the standard choices for load-cell and strain-gauge projects, and for good reason: it is built around that exact task. It offers 24-bit conversion, two channels, and gain settings tailored to the tiny signals you get from bridge-based sensors. For scales and force sensors, it is usually a more logical choice than a general ADC breakout. Its main limitation is that it is specialised, so it is not the board you would pick for reading a mix of everyday analogue sensors. **Key specs:** - **Device type:** Load-cell / bridge-sensor ADC breakout - **Resolution:** 24-bit - **Channels:** 2 - **Interface:** SPI **Pros:** - Purpose-built for load cells and strain gauges - 24-bit resolution - Two channels available - Gain options suit very small bridge outputs - Breadboard-friendly breakout format **Cons:** - Specialised rather than general-purpose - Less suitable for ordinary analogue sensor expansion --- ## MCP3424 18-Bit ADC-4 Channel with Programmable Gain Amplifier _Best for multi-channel precision over I2C_ **Price:** $20.34 · **Stock:** Available (supplier stock) **Product page:** https://littlebirdelectronics.com.au/products/mcp3424-18-bit-adc-4-channel-with-programmable-gain-amplifier The MCP3424 is a useful middle ground between single-channel precision converters and mainstream 4-channel ADC boards. It gives you 4 channels, 18-bit delta-sigma conversion and a programmable gain amplifier, which makes it appealing for slower but more detailed measurements. If your project needs several precision channels over I_2_C, this is a stronger fit than an ADS1015. It is less of a plug-and-play generalist than the ADS1115, but more capable for weak-signal measurement. **Key specs:** - **Device type:** Precision ADC breakout - **Resolution:** 18-bit - **Channels:** 4 - **Interface:** I2C / STEMMA QT / Qwiic **Pros:** - 18-bit resolution - 4 channels - Programmable gain amplifier - I2C interface suits Arduino and Raspberry Pi - Good fit for weak-signal measurement **Cons:** - More specialised than common entry-level ADC boards - Not the obvious choice if simple sensor reading is the goal --- ## ADS1015 12-Bit ADC - 4 Channel with Programmable Gain Amplifier _Best for faster general sensing_ **Price:** $19.41 · **Stock:** In stock **Product page:** https://littlebirdelectronics.com.au/products/ads1015-12-bit-adc-4-channel-with-programmable-gain-amplifier The ADS1015 is a straightforward general-purpose ADC for makers who want easy I_2_C wiring, four channels and faster updates than the ADS1115. Its 12-bit resolution is enough for many classroom and hobby projects, especially where responsiveness matters more than squeezing out extra detail. At up to 3,300 samples per second, it is the better pick for quicker-changing analogue signals in this I_2_C family. The trade-off is lower resolution, so it is less attractive for fine measurement than the 16-bit ADS1115. **Key specs:** - **Device type:** General-purpose ADC breakout - **Resolution:** 12-bit - **Channels:** 4 - **Interface:** I2C / STEMMA QT - **Operating voltage:** 3.3V / 5V **Pros:** - 4 channels with single-ended or differential options - Up to 3,300 samples per second - Programmable gain amplifier - Simple I2C wiring - STEMMA QT / Qwiic support **Cons:** - 12-bit resolution is lower than ADS1115 - Less suitable for precision measurement --- ## ADS1115 16-Bit ADC - 4 Channel with Programmable Gain Amplifier _Best overall_ **Price:** $31.31 · **Stock:** Out of stock **Product page:** https://littlebirdelectronics.com.au/products/ads1115-16-bit-adc-4-channel-with-programmable-gain-amplifier The ADS1115 is the most balanced option here for everyday maker use. It gives you 16-bit resolution, four channels, differential measurement options and a programmable gain amplifier, all over a simple I_2_C connection that plays nicely with Arduino, Raspberry Pi and other boards. It is not the fastest converter in the group, but for most sensor projects that is a worthwhile trade-off for the extra detail over a 12-bit part. If you are not sure where to start, this is the safest all-round choice. **Key specs:** - **Device type:** General-purpose ADC breakout - **Resolution:** 16-bit - **Channels:** 4 - **Interface:** I2C / STEMMA QT - **Operating voltage:** 3.3V / 5V **Pros:** - 16-bit resolution suits a wide range of sensor projects - 4 channels with single-ended or differential modes - Programmable gain amplifier - Easy I2C integration - Well suited to Arduino, Raspberry Pi and general microcontrollers **Cons:** - Slower than ADS1015 at 860 samples per second - Costs more than entry-level ADC options --- ## ADS122C04 24-Bit 4-Channel I2C ADC Breakout _Best high-resolution general ADC_ **Price:** $47.62 · **Stock:** Out of stock **Product page:** https://littlebirdelectronics.com.au/products/adafruit-ads122c04-24-bit-adc-4-channel-2-ksps The ADS122C04 is a more advanced high-resolution option for makers who need more than a typical 16-bit I_2_C ADC can offer. It combines 24-bit conversion, 4 channels and data rates up to 2 kSPS, which makes it one of the more capable general ADC breakouts in this lineup. It sits above boards like the ADS1115 in both capability and cost. For demanding low-level measurement, scientific logging or more instrument-style projects, it makes sense; for everyday sensor reading, it is often more board than you need. **Key specs:** - **Device type:** High-resolution ADC breakout - **Resolution:** 24-bit - **Channels:** 4 - **Interface:** I2C - **Operating voltage:** 3.3V / 5V **Pros:** - 24-bit resolution - 4 channels - Up to 2 kSPS - Handles single-ended or differential signals - I2C connection keeps wiring simple **Cons:** - Higher cost than mainstream options - Overkill for many basic maker projects --- ## 10-bit ADC (SPI) - 4 Channel _Budget SPI ADC_ **Price:** $5.53 · **Stock:** In stock **Product page:** https://littlebirdelectronics.com.au/products/10-bit-adc-spi-4-channel This 10-bit SPI ADC is a low-cost way to add analogue inputs to a Raspberry Pi or other board that lacks them. It suits straightforward sensor, potentiometer and control-voltage projects where speed and price matter more than high resolution. The SPI interface is quicker than typical I2C ADCs, but it does use more pins and needs a little more wiring. **Key specs:** - **Resolution:** 10-bit - **Interface:** SPI - **Channels:** 4 - **Operating voltage:** 3.3V / 5V - **Chip:** MCP3008 - **Breadboard friendly:** Yes **Pros:** - Inexpensive option for adding analogue inputs - SPI interface is well suited to faster sampling - Works with 3.3V and 5V systems - Breadboard-friendly for quick prototyping **Cons:** - 10-bit resolution is modest compared with 12-, 16- and 24-bit ADCs - SPI uses more microcontroller pins than I2C --- ## 10-bit ADC (SPI) - 8 Channel _Best low-cost SPI option_ **Price:** $6.94 · **Stock:** In stock **Product page:** https://littlebirdelectronics.com.au/products/10-bit-adc-spi-8-channel The MCP3008 is the familiar 8-channel, 10-bit SPI ADC many makers reach for when a Raspberry Pi or digital-only microcontroller needs analogue inputs. It is not the highest-resolution converter in this guide, but it gives you plenty of channels, a straightforward SPI interface, and a useful 200 ksps sample rate at 5V for general sensor and potentiometer work. **Key specs:** - **Resolution:** 10-bit - **Interface:** SPI - **Channels:** 8 single-ended - **Sample rate:** 200 ksps at 5V - **Operating voltage:** 5V - **Chip:** MCP3008 **Pros:** - 8 single-ended analogue input channels - SPI interface suits Raspberry Pi and microcontroller projects - 200 ksps sample rate at 5V - Breadboard-friendly for prototyping - Low-cost way to add analogue inputs **Cons:** - 10-bit resolution is modest compared with 12-bit, 16-bit, and 24-bit options - SPI uses more wiring than I2C modules --- ## SparkFun Qwiic 12 Bit ADC - 4 Channel (ADS1015) _Best Qwiic general sensing_ **Price:** $38.28 · **Stock:** Available (supplier stock) **Product page:** https://littlebirdelectronics.com.au/products/sparkfun-qwiic-12-bit-adc-4-channel-ads1015 The SparkFun Qwiic ADS1015 is a neat pick when you want to add four analogue inputs to a Qwiic-based project without much wiring fuss. Its 12-bit resolution is a practical step up for everyday sensors, and the programmable gain amplifier helps when you need to measure smaller signals more carefully. Compared with higher-resolution ADCs in this guide, it is more about convenient general sensing than precision lab-style measurement. **Key specs:** - **Resolution:** 12-bit - **Interface:** I2C / Qwiic - **Channels:** 4 - **Input modes:** Single-ended or differential - **Operating voltage:** 3.3V - **Gain:** Programmable gain amplifier **Pros:** - Qwiic connector makes I2C wiring straightforward - Four analogue input channels - Supports single-ended or differential inputs - Programmable gain amplifier for small signal ranges - Breadboard-friendly for prototyping **Cons:** - 12-bit resolution is lower than 16-bit and 24-bit options - 3.3V operation may need level consideration in some 5V projects --- ## MCP3008 - 8-Channel 10-Bit ADC With SPI Interface **Price:** $6.95 · **Stock:** In stock **Product page:** https://littlebirdelectronics.com.au/products/mcp3008-8-channel-10-bit-adc-with-spi-interface --- ## Gravity: 0-10V 15-bit High-Precision Dual-Channel ADC Module **Price:** $24.00 · **Stock:** Available (supplier stock) **Product page:** https://littlebirdelectronics.com.au/products/gravity-0-10v-15-bit-high-precision-dual-channel-adc-module --- ## Adafruit PCF8591 Quad 8-bit ADC + 8-bit DAC - STEMMA QT / Qwiic _Best ADC/DAC combo_ **Price:** $13.15 · **Stock:** Available (supplier stock) **Product page:** https://littlebirdelectronics.com.au/products/adafruit-pcf8591-quad-8-bit-adc-8-bit-dac-stemma-qt-qwiic The Adafruit PCF8591 is a handy pick when you need a few simple analogue inputs and a basic analogue output on the same I2C breakout. Its 8-bit resolution is modest compared with the ADS1115 or MCP342x boards, but it keeps wiring easy with STEMMA QT/Qwiic and suits potentiometers, light sensors, and classroom experiments where convenience matters more than fine precision. **Key specs:** - **Resolution:** 8-bit - **Interface:** I2C / STEMMA QT - **ADC Channels:** 4 - **DAC Channels:** 1 - **Ecosystem:** QT Py / STEMMA QT **Pros:** - Four analogue input channels - Includes an 8-bit analogue output - Easy I2C connection via STEMMA QT/Qwiic - Good fit for basic sensor and teaching projects **Cons:** - Only 8-bit resolution - Not suited to precision measurement or fast sampling tasks --- ## Gravity: I2C ADS1115 16-Bit ADC Module (Arduino Raspberry Pi Compatible) _Best for Gravity sensor projects_ **Price:** $27.37 · **Stock:** Available (supplier stock) **Product page:** https://littlebirdelectronics.com.au/products/gravity-i2c-ads1115-16-bit-adc-module-arduino-raspberry-pi-compatible This DFRobot ADS1115 module is a tidy fit when you want to add 16-bit analogue input to a Raspberry Pi, Arduino, or other I2C-capable board. In this comparison it sits close to the general ADS1115 breakouts, but the Gravity ecosystem angle makes it especially convenient for plugging in DFRobot analogue sensors without much wiring fuss. **Key specs:** - **Resolution:** 16-bit - **Channels:** 4 - **Interface:** I2C / STEMMA QT / Qwiic - **Function:** ADC - **Compatibility:** Arduino, Raspberry Pi - **SKU:** DF-DFR0553 **Pros:** - 16-bit resolution for finer sensor readings - 4 analogue input channels - I2C interface keeps wiring simple - Handy match for Gravity analogue sensors - Suitable for Raspberry Pi projects that lack analogue inputs **Cons:** - Only 4 channels, so larger logging setups may need another ADC - I2C is not the pick for very high-speed sampling --- ## How we chose We assessed these boards using the factors makers usually care about most in real projects rather than datasheet trivia alone. That means balancing resolution, speed, wiring complexity, channel count and how broadly useful each board is across common classroom, hobby and prototyping jobs. - **Resolution:** More bits can help with small-signal work, but only if the application actually benefits from it. - **Channels:** A single precision channel suits some instruments, while data logging and sensor arrays often need 4 or 8 inputs. - **Interface:** I_2_C is usually easier to wire and expand; SPI and specialised digital interfaces can be better for speed or dedicated sensor front ends. - **Application fit:** Some products here are general ADCs, while others are tuned for load cells, USB-connected measurement, or power monitoring. - **Ease of use:** Breadboard-friendly layouts, STEMMA QT / Qwiic support and compatibility with Arduino or Raspberry Pi matter for faster prototyping. - **Value in context:** We looked at what each board offers relative to its intended job, not just its price tag. ## What is it & how does it work? An ADC is a chip that converts an analogue voltage into a digital number your microcontroller or computer can read. If you are measuring something like a potentiometer, light sensor, thermistor or microphone signal, the sensor output is usually analogue. The ADC samples that voltage and reports it as a value based on its resolution, such as 10-bit, 12-bit, 16-bit or higher. In practice, a higher-resolution ADC can show finer changes in signal level, while a faster ADC can capture changing signals more quickly. The interface also matters: **I2C** uses fewer wires and is very beginner-friendly, while **SPI** or other specialised digital links can be preferable for higher throughput or dedicated measurement tasks. An external ADC is often worth adding when your board has no analogue inputs at all, when its built-in ADC is too low-resolution, or when you need more channels or better differential measurement. ## What to look at when comparing If you are choosing between ADC boards, start with the actual signal you need to measure and work backwards. The right choice for a weight scale is very different from the right choice for reading a few knobs or logging several analogue sensors. - **Resolution:** 8-bit and 10-bit suit simple controls and rough measurements. 12-bit and 16-bit are better for general sensor work. 18-bit to 24-bit boards are more appropriate for small differential signals and precision measurement. - **Sample rate:** Faster converters are more useful for changing signals. Slower, high-resolution delta-sigma parts are often better for stable measurements. - **Channel count:** Think about how many sensors you need to read now and later. Extra channels can save redesigns. - **Single-ended vs differential:** Differential inputs are useful for tiny signals and noisy environments. - **Gain and reference features:** A programmable gain amplifier or built-in precision reference can make a big difference for low-level sensors. - **Interface and pin use:** I_2_C is simpler and suits many education and maker builds. SPI or dedicated load-cell interfaces can be a better fit for specialised jobs. - **Voltage compatibility:** Check supply and logic voltage against your board, especially when moving between 3.3V and 5V systems. - **Platform fit:** Raspberry Pi users often need an external ADC for any analogue sensing at all, while many Arduino boards already have some built-in analogue capability. **Which should I buy?** - **Choose ADS1115** if you want the safest all-rounder for general analogue sensor projects. - **Choose ADS1015** if you want similar ease of use but care more about speed than extra resolution. - **Choose ADS7830** if channel count matters more than precision. - **Choose MCP3421 or MCP3424** for precision differential measurements over I_2_C. - **Choose HX711 or NAU7802** for load cells and strain gauges. - **Choose ADS122C04** if you want a more advanced high-resolution I_2_C option. - **Choose MCP2221A** if your measurement workflow starts from a computer over USB rather than a standalone MCU. ## Alternatives to consider If none of these boards quite fits, there are a few nearby categories worth considering. A microcontroller with a decent built-in ADC may be enough for basic potentiometers, LDRs and temperature sensors. For current, voltage and power measurement, a dedicated power monitor is often more useful than a general ADC. For magnetic field, motion or environmental sensing, a digital sensor breakout with its own onboard conversion can simplify wiring and software. And if you are working with audio or high-speed acquisition, a dedicated codec or faster data-acquisition hardware may be a better match than the slower precision ADCs covered here. ## Bottom line For most makers, the **ADS1115** is the easiest recommendation because it balances useful 16-bit resolution, four channels, differential options and simple I_2_C wiring. If your priority is faster updates on a budget, the **ADS1015** is a sensible step down; if you need many channels, look at the **ADS7830**; and if you are reading load cells, go straight to a dedicated board such as the **HX711** or **NAU7802**. The more specialised high-resolution parts make sense once you know your signal is small enough, slow enough or demanding enough to justify them. --- Reviewed by **Marcus Schappi** — Co-founder, Little Bird Electronics. Working with Australian makers, educators and engineers since 2011.