node-red-contrib-minimodem

A node red node for text (de)coding to audio.It essentialy just executes the minimodem in the background.

Instalation

To setup the nodes to work in the node-red there are several things that needs to be setup first. We essentialy first need minimodem to be installed via packet manager.

sudo apt install minimodem

The node was originaly developed on Manjaro, and it worked perfectly. So i wanted to test it on the Raspberry PI 4. For the RPI (Raspberry Pi OS) you would need to setup pulseaudio and set it on boot. You can follow this stackexchange answer

To install the node open pallet manager and search for node-red-contrib-minimodem

Nodes

Listen Node - Node for receiving/listening for audio to decode to text. Send Node - Node for converting msg.payload to audio, and playing the audio.

Additional Functions

Send node accept options overwrite via msg.payload

msg.baudmode == number
msg.autocarrier == boolean
msg.inverted== boolean
msg.bandwithval == number
msg.markval == number
msg.spaceval == number
msg.startbitsval == number
msg.stopbitsval == number
msg.invertstartstop == boolean
msg.syncbyteval == string
msg.quiet == boolean
msg.samplerateval == number
msg.floatsample== boolean

Repeat

Send node also haves a repeat function , it can be triggered via send node options or by passing some msg values via payload. Example:

msg.repeatdelay = 1000 
msg.repeatxtimes = 3

Confirm if whole message arrived

I wanted to implement a function that will check if whole message arrived. So i wrote an option if checked on the send node Send letter number to add msg.payload lenght between square brackets ([]) and append it to the end of the message.

If this option is also checked on the listen node Check received string when the message is received msg.minimodem.receivedmatch will output true and msg.minimodem.receivedlenght will output the lenght of the message.

Output

Depending on the selected options of listen node, msg.payload will always be the message that is received trought minimodem. Listen nodes also outputs the msg.minimodem object that contains:

1. Received Lenght info.
2. Time of received.
3. Selected options from node options.

NOTE

I have not tested this node whole lot, but i know that in order to send and receive a message you will need to setup same options on both listen and send nodes!

Bugs

There are some bugs for node status messages, that i plan to fix in the future, but i wanted to see what node red community thinks about my of coding skills.