ESP8266-based WiFi serial modem emulator ROM
README: Add installation instructions for the WiModem232
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## WiFiPPP
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Yet another ESP8266-based WiFi serial modem emulator ROM featuring a Hayes
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AT-style command interface that emulates a serial modem and allows old hardware
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to "dial" telnet addresses rather than phone numbers.
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It also includes a built-in PPP server that routes through the WiFi interface,
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reachable with `ATDT PPP`.
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Inside the PPP connection is a SOCKS5 proxy that can strip TLS from common
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services like HTTPS and IMAPS, allowing old hardware to talk to modern, secure
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services without needing to do any TLS.
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### WiModem232
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WiFiPPP currently targets the
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[WiModem232](https://www.cbmstuff.com/index.php?route=product/category&path=59_66)
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hardware, which includes:
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- ESP8266-12F WiFi module
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- (Optional) I2C-based
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[SSD1306 monochrome OLED](https://amzn.to/3zs39OL)
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(with blue and yellow sections)
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- [NeoPixel 5050 multi-color LED](https://www.adafruit.com/product/1655)
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with an integrated WS2811 controller
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### Installation
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For the WiModem232, installation will replace the factory ROM image, though no
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hardware modification is needed.
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The device can be revered back to stock by just flashing the
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[factory ROM](http://www.cbmstuff.com/updates/wimodem232_V2_update.bin)
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again.
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This manual installation will only be required once, since future updates can
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use the built-in `AT$UPDATE` command to do an over-the-air update over WiFi.
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First, clone this Git repo and compile the WiFiPPP ROM.
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$ git clone --recursive https://github.com/jcs/WiFiPPP
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[...]
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$ cd WiFiPPP
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WiFiPPP$ gmake
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On the back side of the WiModem232 (with the USB port facing down) are 5
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vertical sockets.
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From top to bottom, these are:
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1. GPIO0 (to enter bootloader)
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2. TX
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3. RX
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4. 3.3v VCC
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5. GND
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Connect a
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[4- or 5- pin USB TTL serial cable](https://amzn.to/3kxsssl)
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to the bottom 4 sockets.
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It is recommended to use a breadboard so the 3.3V VCC and GND pins can be
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connected to the breadboard's `+` and `-` rails, and then connect wires from
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those rails to the sockets on the WiModem232.
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Connect a jumper wire between the top port (GPIO0) port and the GND rail.
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Connect another jumper wire to the GND rail which will be used to reset the
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ESP8266.
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Run `gmake install` to launch `esptool` and prepare to flash the WiFiPPP ROM
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through the USB TTL cable.
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Touch the jumper wire from the GND rail to the RST pin on the ESP8266, which is
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the bottom-most pin along the right-hand side.
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The blue LED will flash briefly, and if the GPIO0 socket is correctly connected
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through your other jumper wire to GND, the ESP8266 will reboot to the
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bootloader.
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`esptool` should see this and start uploading the ROM automatically.
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After flashing, disconnect the GPIO0 jumper wire or else it will reboot into
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bootloader again.
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Touch the RST pin again and the device should boot and show WiFiPPP on the OLED
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screen (if your model has one).
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In a serial terminal connected to your USB TTL device at any baud rate, you
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should see some junk from the bootloader after rebooting.
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Hit enter and type `AT` and it should echo back.
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If all is working properly, you can disconnect all of your cables and connect
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through the DB25 port (but not at the same time).
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You'll need to re-establish your WiFi settings since the EEPROM layout from
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WiFiPPP is not compatible with the factory WiModem232 settings.