ICE-V-Arduino

Arduino-based ESP32 firmware for the ICE-V Wireless board

Abstract

This project is a version of the ICE-V Wireless firmware ported to the Ardunio ESP32 environment. It includes the well-known WiFiManager SoftAP captive portal to do the initial SSID/Password setup as well as an option to restart the setup at any time by pressing the BOOT button for three seconds. It supports power-on initialization of the ICE40UP5k FPGA from a stored default as well as wireless programming of the FPGA, SPI access after configuration, PSRAM read/write and battery voltage monitoring.

Prerequisites

You'll need the following resources:

• Arduino IDE. Get it here: https://www.arduino.cc/en/software
• ESP32 for Arduino. Get it here: https://github.com/espressif/arduino-esp32
• WiFiManager library. Get it here: https://github.com/tzapu/WiFiManager

Go to each of the above sites and follow the directions for a normal installation. Once that's complete you should be able to build this project.

Building

Open up the ICE-V.ino project in the Arduino IDE.

Prior to building you need to do the board configuration in the Arduino IDE. Navigate to the "Tools" menu and set the following options:

• Board: ESP32C3 Dev Module
• Upload Speed: (anything - the USB port max speed will be used)
• USB CDC On Boot: Enabled
• CPU Frequency: 160MHz (WiFi)
• Flash Frequency: 80MHz
• Flash Mode: QIO
• Flash Size: 4MB
• Partition Scheme: Default 4MB with spiffs
• Core Debug: Verbose
• Port: (see below)

Connect the ICE-V board to your build host by USB and drag down to the "Tools->Port" menu item - drag right and select the port your device has connected to.

Now open up the "Tools->Serial Monitor" so you can see the log messages when you firmware boots up.

Click the (->) Upload button to compile and flash the project to your hardware. This may take some time and you will see progress messages scrolling by in the IDE status window. Once the board boots up new firmware you should see progress in the Serial Monitor window telling you what's going on. On the first boot there will be a slight delay while the SPIFFS file system is initialized and then the WiFiManager SoftAP should start up.

Provisioning

Use any device with a web browser and Wifi connection to configure the WiFi credentials. Open up your WiFi network browser and search for a network named ICE-V_AP. Connect to that network and provide the password ice-vpwd.

After the captive portal webpage appears you will see several buttons - press the "Configure WiFi" button and a list of available networks will appear. Select your network and provide the password. The captive portal will shut down and the ICE-V board will join your network.

Resetting Credentials

If you want to clear out the network credentials for any reason you can do so by pressing the BOOT button on the ICE-V board for approximately 3 seconds. This will wipe the existing network SSID and password and force a restart into the SoftAP/Captive Portal to re-enter new credentials.

Network Addressing

The WiFi networking stack in this firmware uses DHCP to request an IP address on your router and mDNS to advertise its name. Each ICE-V board will have a unique mDNS name of ice-v_XXXXXX.local after it successfully connects to your network, where XXXXXX is the hexadecimal value of the last three octets (bytes) in the MAC address assigned to the ESP32C3 chip by the factory. You can determine this name by reading it from the Serial Monitor window of the Arduino IDE during boot-up.

In addition to the hostname, the firmware also advertises a TCP service _FPGA on port 3333. You can use an mDNS browser such as avahi-browse on Linux to find the hostname (without the .local suffix) without needing to see the serial log output.

Note: after the SoftAP/Captive Portal shuts down your ICE-V board will have a name of esp32c3-XXXXXX.local. On subsequent boots with good network credentials it will be named ice-v_XXXXXX.local so once your board is able to access your network you may want to touch reset to restart with a more normal network name.

Default FPGA configuration

After installing the firmware for the first time, the SPIFFS filesystem will be empty and the FPGA will not be configured on power-up. If you want to have a default FPGA configuration at power-up then you need to use the host-side python script send-c3sock.py to send the desired configuration to the ICE-V board. That python script is available in the baseline ICE-V firmware repository here:

https://github.com/ICE-V-Wireless/ICE-V-Wireless/tree/main/python