Proto HAT

This documentation includes hardware info, installation guidelines and sample code for your hardware.

Overall Info

Proto HAT is a prototyping board with an onboard analog-to-digital converter for Raspberry Pi.



  • I2C Pads: Provides I2C connectivity with the 'SCL' and 'SDA' pads. There are three 'SCL' and three 'SDA' pads onboard.

  • UART Pads: Provides serial port connectivity with the 'TX' and 'RX' pads.

  • SPI Pads: Provides SPI connectivity with the 'MO' (MOSI), 'MI' (MISO), 'SCK', and 'CE1' pads. (CE0 is connected to the ADC IC.)

  • Analog Pads: Provides four single-ended ('A1', 'A2', 'A3', and 'A4') or two differential analog inputs. ('A1'-'A2' and 'A3'-'A4')

  • Free Pads: 5x22 Empty pads.

  • Breadboard Style Pads: 2x22 Columns breadboard style pads.

  • Power Pads: One '5V', two rows '3.3V' and two rows 'GND' pads.

  • Stackable Raspberry Pi Connector: Connects the board to the Raspberry Pi. The connector is stackable.

I2C, UART, SPI, GPIO, and Analog ports are 3.3V tolerant.


  • 5x22 Free pads.

  • 2x22 Columns breadboard style pads.

  • 13 GPIO, I2C, SPI, UART (Serial), and 5V pads on the top row.

  • 2 Rows 3.3V, 2 Rows GND pads.

  • Additional I2C Pads on the breadboard area.

  • Analog-to-Digital Converter over the SPI CS0.

  • 4Ch single-ended or 2Ch differential analog inputs are available.

  • Board temperature reading on the ADC IC.

  • Slot for Raspberry Pi's CSI Camera Port.

  • Stackable Raspberry Pi header.

  • ID EEPROM for Raspberry Pi HAT specification compliance.

  • Pads are numbered for easy content creation.


Proto HAT's specifications are as follows:

TI ADS1018 Analog-to-Digital Converter

Measures 4x analog inputs and internal temperature.

  • 4 Channel Single-Ended Sampling:

    • 0V to 3.3V measurement with 1/1650 resolution. (2.000mV)

    • 0V to 2.048V measurement with 1/4096 resolution. (1.000mV)

    • 0V to 1.024V measurement with 1/4096 resolution. (0.500mV)

    • 0V to 0.512V measurement with 1/4096 resolution. (0.250mV)

    • 0V to 0.256V measurement with 1/4096 resolution. (0.125mV)

  • 2 Channel Differential Sampling:

    • Same of above resolutions.

  • Internal Temperature Measurement:

    • Used for system-level temperature monitoring or cold-junction compensation for thermocouples.

    • 2C max error.

  • Programmable Continuous Sampling:

    • 128 to 3300 samples per second.

    • High speed SPI bus.

This device uses the CS0 line of the SPI bus.


This memory holds manufacturer information, GPIO setup and device tree. The OS loads required drivers and configures GPIO pins according to the data on this memory. ID EEPROM is required for Raspberry Pi HAT specification compliance.

Do not try to overwrite or erase the contents of the EEPROM as it may block the device's operation.

The EEPROM is connected to the I2C1 bus and requires root privileges for user access.


To get maximum performance from your hardware, please make sure you'll meet the following requirements.


We designed Proto HAT to work with Raspberry Pi. Alternatively, you may wish to use any Raspberry Pi pin compatible device as an host.

Operating System

You can use Proto HAT with any operating system that supports I2C, UART and SPI communications and GPIO access. We officially support Raspbian operating system.

Development Environment

Proto HAT's Raspbian library supports Python. You can write Python code in any text editor. We recommend using Visual Studio Code as an editor.


Select your operating system for set-up and programming guidelines.

Raspberry Pi OS

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