I am a member of a local search and rescue team.
I found this Linux project : [login to view URL]
And i got the idea for a device that can be plugged in to any vox device and send text messages of course the raspberry pi has to use a usb sound card for mic=Rx, speaker=Tx.
so the idea is to have a Raspbeerry pi with an lcd module on, there will be 16 ss49 linear hall effect sensors that will sent their signal to an ADC so it provide the values to one of the pins of the raspberry pi. the use of the 16 sensors will be like buttons to an old mobile phone ( read the value, and when the pass a thresshold, consider it as key press). 12 of them for numbers 0 to 9, *, # and 4 buttons on the right with special functions ( send, read, clear, backspace). like this arduino project : [login to view URL]
Only this time everything will be under plastic, no moving parts and all you need to operate is a magnet attached to the point of a stylus. ROBUST.
The raspberry pi has to have functions for storring old messages, access and reading them, and ofcourse the edit and transmite a new one. The transmitting of the message will be pipped to minimodem so it can be transmitted through sound over a vox VHF/UHF TRANSEIVER.
When the device will be turned on it will automatically turn on the rx of minimodem so it can receive any incomming message. If there is an incomming message no message will be sent untill the receiving message is finished.
An other functionality that i would like to have is set a hartbeat function, for example 1 minute or 1 seccond to transmite on repeat data from sensors to the base camp device( practically a clone of this device, located to base camp ) so the base knows gps coordinates, air presure, temperature, compass ect of people out there on missions. of course the people that will be using those devices can have a screen to look at their data : gps coordinates, air presure(altitude), temperature, compass.
I will need the code for visual represantation of the texter and sensor representation, and gerber schematics of the sheild.
I've managed to have this mcp3002 ADC and a 4067 16 to 1 multiplexor work with raspberry pi in python so i can read 16 analogue devices and work as a texter in terminal of my raspberry pi with minimodem installed, find the code in uploaded files.
All I need is some help with the visualisation part of the of the data and the gerber files of PCB so i can have a prototype ordered.