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Create amazing Internet of Things designs without soldering or dropping down to C. The GRiSP project makes building internet-connected hardware devices easier with Erlang!

• Real bare-metal Erlang virtual machine (no operating system!)
• Hard real-time event handling, using open source code
• Digilent Pmod™ compatible connectors for sensors and actuators

This repository contains the Erlang runtime and support code for the GRiSP hardware platform.

Getting Started

The easiest way to get started is to use the Rebar 3 or Mix plug-ins for GRiSP.

Erlang

Install the GRiSP Rebar 3 plug-in globally by adding {plugins, [rebar3_grisp]}. to ~/.config/rebar3/rebar.config.

Create a new project:

# Create a new GRiSP application (use the real mount path of your SD card)
rebar3 new grispapp name=demo dest=/path/to/SD-card
cd demo

# Deploy the application to your SD-card
rebar3 grisp deploy

Hardware

GRiSP hardware supports many different connection standards:

• GPIO
• SPI
• UART
• I²C
• 1-Wire

Peripherals can be connected to either PMOD ports or I/O pins directly.

GRiSP 2 (grisp2)

GRiSP 2 ships with the following features:

• 1 × 100 Mbit/s Ethernet port
• 1 × Wi-Fi 802.11b/g/n WLAN
• 1 × GPIO PMOD Type 1A (12-pin)
• 2 × GPIO pins (14-pin & 6-pin)
• 1 × SPI1 PMOD Type 2 (6-pin)
• 1 × SPI2 PMOD Type 2A (12-pin)
• 1 × UART PMOD Type 3A (12-pin)
• 1 × I²C PMOD Type 6 (6-pin)
• 1 × I²C Bus (8-pin)
• 1 × 1-Wire Bus (3-pin)
• 1 × USB Bus (5-pin)
• 5 × mode DIP switches
• 1 × JTAG connector

GRiSP 1 (grisp_base)

GRiSP 1 ships with the following features:

• 1 × Wi-Fi 802.11b/g/n WLAN
• 2 × GPIO PMOD Type 1 (6-pin)
• 1 × UART PMOD Type 3 (6-pin)
• 1 × SPI1 PMOD Type 2A (12-pin)
• 1 × SPI2 PMOD Type 2 (6-pin)
• 1 × I²C Bus (8-pin)
• 1 × 1-Wire Bus (3-pin)
• 5 × mode DIP switches
• 1 × JTAG connector

Testing

The project has a [hardware emulation layer in software][grisp_emulation] that allows you to use the runtime locally on a normal computer. To start a local shell for the runtime use:

$ rebar3 as test shell

Glossary

1-Wire

Long-distance serial communication bus.

GPIO

General Purpose Input/Output. Digital signal pin interface used to interface with single pins.

I²C

Inter-Intergrated Circuit. Short-distance synchronous serial computer bus.

JTAG

On-chip instrumentation and debugging interface.

PMOD

A peripheral device that implements the [Digilent Pmod™ connection form factor and interface][PMOD].

Slot

A physical slot where a component can be connected. E.g. `SPI1` where an SPI PMOD can be connected.

SPI

Serial Peripheral Interface. Synchronous serial communication interface.

UART

Universal Asynchronous Receiver-Transmitter. Asynchronous serial communication interface.