TI-NSpire SMS Shield
Connecting my Ti-Nspire to the world of sms

Why and how
It all started in a German class I had. I was talking to a friend, and we said that it could be awesome to send sms with our TI. After one-two months, I started to do some digging and found out about some "shield" that could be snapped into the bottom connector of the nSpire. After googling a bit I found out that a few people actually did research on this, so this is what I did and here are the 4 pins that I'm interested in:

After quickly soldering some wires to it and connecting a FTDI breakout board to it, I reset the calculator, and it started dumping out the boot log, so that told me that this could actually work. Now I need a way to access it in software. I searched a bit and found ndless. It's mainly used to play games, but a full SDK to cross compile c for the nSpire. Next I found the nspire-io lib after testing I found that sending was ok the receiving was a pain due to some compatibility issue with different models of TI. After speaking to the author and some nice peoples on the codewalr forum, I modified the source code and it worked. After re-creating a function, it allowed me to receive data until a newline (\n)
char* uart_getsn(char* str, int num) {
int i = 0;
int max = num-1;
while(1 && releasefunc()) {
while(uart_ready() && isKeyPressed(KEY_NSPIRE_ESC)) {
if(i == max) {
str[i] = 0;
return str;
}
char c = uart_getchar();
str[i] = c;
if(c == '\b'){ i -= 2; }
else if(c == '\r') { str[i] =0; return str; }
i++;
}
}
}
After doing some CAD I had it all working and well. Here are source ode link and cad files: GITHUB
Photos


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