iCESugar Nano Development Examples

A comprehensive collection of Verilog projects for the iCESugar Nano FPGA board demonstrating LED control, PWM effects, UART communication, and microcontroller implementations.

Structure

• constraints/ - Pin Constraint File (.pcf) for iCESugar Nano
• src/PE-Library/ - Verilog library templates
• src/projects/ - Example projects organized by complexity

Quick Start

git clone https://github.com/abhinav937/icesugar_nano_examples.git
cd icesugar_nano_examples
cd src/projects/blinky

Projects Overview

Basic LED Projects

Project	Description	Pin Mapping
blinky	Simple LED blink at 1 Hz	LED → B6
pwm_led	PWM-based LED breathing effect	LED → B6
train_leds	Pulsating effect across PMOD3 pins	B4, B3, B2, B1, A4, A3, A2, A1
fpga_done_led	Turn off B4 LED when FPGA is programmed	LED → B4

UART Communication Projects

Project	Description	Pin Mapping
uart_pwm_led	UART-controlled LED brightness	LED → B6, UART → B7, B8
multi_led_uart	Multi-LED UART control with brightness setting	PMOD3 pins, UART → B7, B8
lowpass_pwm_uart	Low-pass filtered PWM demo with bar graph	B6 (filtered PWM), PMOD1-8 (bar graph)

Advanced Control Projects

Project	Description	Pin Mapping
pwm_microcontroller	8-bit microcontroller with dual PWM channels	PWM0 → B4, PWM1 → C6, UART → A3, B3
closed_loop_control	Closed-loop control system with UART feedback	PWM → B6, UART → A3, B3

Project Details

Basic LED Projects

blinky - Simple LED toggle at 1 Hz frequency, perfect for first-time FPGA users.

pwm_led - Demonstrates PWM (Pulse Width Modulation) to create a smooth breathing effect on an LED.

train_leds - Creates a moving light pattern across 8 LEDs on PMOD3, simulating a train of lights.

fpga_done_led - Shows how to control an LED based on the FPGA's programming state.

UART Communication Projects

uart_pwm_led - Controls LED brightness via UART commands, demonstrating serial communication.

multi_led_uart - Advanced UART control for multiple LEDs with individual brightness control.

lowpass_pwm_uart - Combines PWM with low-pass filtering and includes a visual bar graph display.

Advanced Control Projects

pwm_microcontroller - Implements a simple 8-bit microcontroller with:

• Dual PWM channels (1kHz frequency)
• UART RX/TX communication
• Command protocol for PWM control
• Acknowledgment system

closed_loop_control - Demonstrates closed-loop control with:

• UART voltage input (0-255 representing 0.0V-25.5V)
• Proportional control law: d[n] = 0.4167 + Kp*(5 - Vout[n])
• 10kHz PWM output
• Real-time duty cycle feedback via UART

UART Settings

• Baud rate: 115200
• Data format: 8N1 (8 data bits, no parity, 1 stop bit)
• Compatible with: iCELink USB CDC interface

Building and Programming Projects

This repository uses a custom workflow with the Lattice_NanoIce flash tool and ssh-push for FPGA programming.

Prerequisites

1. Install Lattice_NanoIce Flash Tool:

   bash <(curl -s https://raw.githubusercontent.com/abhinav937/Lattice_NanoIce/main/install.sh)

2. Install ssh-push (if not already installed):

   # Clone and install ssh-push
   git clone https://github.com/abhinav937/ssh-push.git
   cd ssh-push
   ./install.sh

Building and Programming

# Navigate to any project directory
cd src/projects/[project_name]

# Build and program using the flash tool
flash [module_name].v [module_name].pcf

# Example for blinky project:
cd src/projects/blinky
flash blinky.v blinky.pcf

# Example for pwm_microcontroller:
cd src/projects/pwm_microcontroller
flash pwm_microcontroller.v pwm_microcontroller.pcf

Advanced Flash Tool Options

# Verbose output for debugging
flash [module_name].v [module_name].pcf --verbose

# Build only (skip programming)
flash [module_name].v [module_name].pcf --build-only

# Set clock frequency (1=8MHz, 2=12MHz, 3=36MHz, 4=72MHz)
flash [module_name].v [module_name].pcf -c 2

# Force drag-and-drop programming
flash [module_name].v [module_name].pcf --force-dragdrop

Alternative: Using ssh-push

For remote development or automated builds:

# Navigate to project directory
cd src/projects/[project_name]

# Push and program via SSH (uses .ssh_push_config.json for connection details)
ssh-push [module_name].v [module_name].pcf

# Example for blinky project:
cd src/projects/blinky
ssh-push blinky.v blinky.pcf

# Example for pwm_microcontroller:
cd src/projects/pwm_microcontroller
ssh-push pwm_microcontroller.v pwm_microcontroller.pcf

Each project directory contains a .ssh_push_config.json file that specifies the SSH connection details (hostname, remote directory, authentication method, etc.).

Testing

Most projects include Python test scripts for UART communication:

• uart_pwm_led/set_brightness.py
• multi_led_uart/set_led_brightness.py
• multi_led_uart/test_multi_led.py
• pwm_microcontroller/program.py

Troubleshooting

• LED not responding: Check pin mapping in .pcf file
• UART issues: Verify baud rate is 115200 and port settings
• Build errors: Ensure correct constraint file is used
• Programming issues: Check USB connection and driver installation
• Flash tool issues: Run flash --help for available options
• Device not detected: Check USB connection and run flash -c 2 to test device status

Hardware Requirements

• iCESugar Nano FPGA board
• USB cable for programming and UART communication
• Optional: External LEDs or PMOD modules for expanded functionality

Contributing

Feel free to submit issues, feature requests, or pull requests to improve these examples.

License

See the LICENSE file for details.