This is a firmware for the ESP8266 module that emulates an Hayes-compatible modem.
| Command | Description |
|---|---|
| A | Answer incoming call |
| D | Connect (dial) to the following host/ip Examples: ATDP n.n.n.n[:port]. Connect to IP addres n.n.n.n. ATDT hostname.com[:port]. Connect to hostname.com. If not specified, the default port number is 23. |
| E0 | Will not echo commands to the computer |
| E1 | Will echo commands to the computer (so one can see what one types if the computer software does not support echo) |
| H | On hook. Hangs up the phone, ending any call in progress. |
| I0 to I6 | Inquiry, Information, or Interrogation |
| L | Speaker loudness (ignored, always returns OK). |
| M | Speaker off (ignored, always returns OK). |
| O | Return online. Returns the modem back to the normal connected state after being interrupted by the "+++" escape code. |
| Q0 or Q | Quiet mode off, displays result codes, user sees command responses (e.g. OK) |
| Q1 | Quiet mode on, result codes are suppressed, user does not see responses. |
| Sn? | Display register n value |
| Sn=r | Set register n value to r |
| V0 or V | Verbose mode off, display numeric result codes |
| V1 | Verbose mode on, display english result codes (e.g. CONNECT, NO CARRIER, etc.) |
| X0 | Disables extended result codes |
| X1 | Enables extended result codes |
| Z | Reset modem to stored configuration |
| &F | Restore factory settings |
| &W | Store current configuration into eeprom |
When a call is established, type the escape sequence "+++" to switch to command mode.
The firmware supports a small subset of the original EspressIf AT commands.
| Command | Description |
|---|---|
| +UART=baud,data,stop,parity,flow | Serial port configuration. baud - UART baud rate data - data bits (5-8) stop - stop bits (1-2) parity - 0 (none), 1 (odd), 2 (even) flow - flow control (ignored) |
| +CWJAP=ssid,pwd | Connect to access point ssid - string, access point SSID pwd - string, password (ASCII) |
| +CWQAP | Disconnect from access point |
| +CWLAP | List available access points. Response: +CWLAP: ecn,ssid,rssi,mac,ch |
| +CWCIPMUX=mode | Enable multiple connections or not. Only single connection (mode=0) is supported |
| +CWCIPSTART=type,addr,port | Establish a connection to a remote host. type - string, "UDP" only is supported addr - string, remote IP or host name port - number, remote port |
| +CWCIPSEND=length | Send data. Returns ">" to begin receiving the data, when length bytes are received the is are sent. |
| +CWCIPCLOSE | Close connection |
The firmware allows to set and store all registers from 0 to 255, however only a small number have a meaning.
| Register | Description | Range | Default |
|---|---|---|---|
| S0 | Number of rings before Auto-Answer | 0-255 (0=Never) | 0 |
| S1 | Ring counter | 0-255 rings | 0 |
| S2 | Escape character | 0-255, ASCII decimal | 43 ("+") |
| S3 | Carriage Return character | 0-255, ASCII decimal | 13 (Carriage Return) |
| S4 | Line Feed character | 0-255, ASCII decimal | 10 (Line Feed) |
| S5 | Backspace character | 0-255, ASCII decimal | 8 (Backspace) |
| S12 | Escape Code Guard Time | 0–255 fiftieths of a second | 50 (1 second) |
| S15 | Telnet Protocol | 0=Disable, 1=Enable | 0 |
| S37 | Desired telco line speed. | 0-11 | 0 |
By default the module will send and receive its information as fast as the serial connection baud rate allows. However, if you want the true nostalgic feel of a slow modem connection, you can limit the speed by setting the "Desired Telco Line Speed" register (S37). Before dialing, issue the command "AT S37=N" where N is an index defining the desired baud rate: 0=auto (default), 1=75, 2=110, 3=300, 4=600, 5=1200, 6=2400, 7=4800, 8=7200, 9=9600, 10=12000, 11=14400
This firmware is based on the WifiModem code by David Hansel.