Atari 2600 PlusCart-Pico

Description

Atari 2600 PlusCart-Pico is a porting on Al-Nafuur PlusCart to Raspberry Pi Pico platform.

Features

• SD card support for ROMs
• on-board flash storage (1MB or 16MB) for ROMs
• Internet access and WiFi connection (with ESP8266)
• PlusROM support
• PlusStore support

Hardware

PlusCart-Pico consists of these modules:

• Raspberry Pi Pico (purple version is recommended due to more pins available)

  

• Atari 2600 cartridge breakout board link

  

• ESP8266-01 (or ESP32)

  

• SD card breakout board

  

• USB UART (optional for debugging purposes)

  

Connections

RPi Pico pin	module pin
GP2...GP14	cartridge bus ADDR[0...12]
GP22...GP29	cartridge bus DATA[0...7]
GP16...GP19	microSD (MISO, CS, SCK, MOSI)
GP0, GP1, GP15	ESP8266 (TX, RX, RST)
GP20, GP21	USB-UART (RX, TX)

RPi Pico connections are defined in board.h

Build

Development environment is based on PlatformIO with two board profiles: pico and vccgnd_yd_rp2040. At first build all dependency library and whole development environment will be automatically installed and configured by PlatformIO.

Start the build:

pio run -e vccgnd_yd_rp2040
  or
pio run -e pico

First run takes some minutes to complete in order to setup PlatformIO environment.

Upload firmware on board:

Run upload command while pressing BOOTSEL button:

pio run -e vccgnd_yd_rp2040 -t upload
  or
pio run -e pico -t upload

ESP-AT firmware flashing on ESP

PlusCart-Pico uses ESP as wifi frontend and it requires ESP-AT firmware installed on ESP module.

In order to install ESP-AT please refer to release page and download v2.2.1.0_esp8266 if you are using ESP8266 module (ESP01, ...) or v2.2.0.0_esp32 if you are using ESP32 module (WROVER, WROOM32, ...).

Two additional tools are required to flash the ESP-AT firmware: esptool and at.py.

Patching factory_param.bin

Before flashing the file customized_partitions/factory_param.bin needs to be patched to use GPIO3 (RX) and GPIO1 (TX) as UART for AT commands. To proceed with patching use the following command with at.py script:

at.py modify_bin --tx_pin 1 --rx_pin 3 --input customized_partitions/factory_param.bin

The patched file will be named target.bin and is available in the working directory.

ESP-AT firmware flashing on ESP8266

esptool.py --before default_reset --after hard_reset write_flash --flash_mode dio --flash_freq 80m --flash_size 2MB 0x8000 partition_table/partition-table.bin 0x9000 ota_data_initial.bin 0x0 bootloader/bootloader.bin 0x10000 esp-at.bin 0xF0000 at_customize.bin 0xFC000 customized_partitions/client_ca.bin 0x106000 customized_partitions/mqtt_key.bin 0x104000 customized_partitions/mqtt_cert.bin 0x108000 customized_partitions/mqtt_ca.bin 0xF1000 target.bin 0xF8000 customized_partitions/client_cert.bin 0xFA000 customized_partitions/client_key.bin

ESP-AT firmware flashing on ESP32

esptool.py --before default_reset --after hard_reset write_flash --flash_mode dio --flash_freq 40m --flash_size 4MB 0x8000 partition_table/partition-table.bin 0x10000 ota_data_initial.bin 0xf000 phy_init_data.bin 0x1000 bootloader/bootloader.bin 0x100000 esp-at.bin 0x20000 at_customize.bin 0x24000 customized_partitions/server_cert.bin 0x39000 customized_partitions/mqtt_key.bin 0x26000 customized_partitions/server_key.bin 0x28000 customized_partitions/server_ca.bin 0x2e000 customized_partitions/client_ca.bin 0x30000 target.bin 0x21000 customized_partitions/ble_data.bin 0x3B000 customized_partitions/mqtt_ca.bin 0x37000 customized_partitions/mqtt_cert.bin 0x2a000 customized_partitions/client_cert.bin 0x2c000 customized_partitions/client_key.bin