Ti-84 and arduino

Projects General Guidance
1

Hi,

I'm working on a project using a TI-84 calculator and arduino.

I'm trying to start by using the send() command on the calculator to send a string to the arduino, and then have the same string appear on the serial comm on the computer.

I'm not sure if i should use the mini-USB plug on the calculator or the 2.5mm link plug.

I know how to write the code on the calculator, but I'm a bit lost when it comes to the hardware and arduino software.

Any advice from anyone is welcomed!

Thanks

2

can you connect it to a PC and capture the serial output using a terminal capture program like RealTerm or EasyTerm and post that so we know what to expect from the calculator and at the same time verify it is sending serial at some specific speed ?

3

I tried this before.
When plugged into a PC, the calculator isn't recognized as a serial port.
Instead it is recognized as a TI handheld educational device, and the drivers from TI are installed.

4

If a PC can't communicate without a driver , I don't know how you will be able to communicate with an arduino. You can try it but generally it is necessary to know the communication protocol before attempting such a thing. Have you figured out if it is RS232?

5

I'm not sure about the protocol, it would be easier if it was rs-232...

I know that 2 ti-84's can be linked together using a usb-mini to usb-mini cable.

6

You didn't say what arduino you have.

7

booliminator:
Hi,

I'm working on a project using a TI-84 calculator and arduino.

I'm trying to start by using the send() command on the calculator to send a string to the arduino, and then have the same string appear on the serial comm on the computer.

I'm not sure if i should use the mini-USB plug on the calculator or the 2.5mm link plug.

I know how to write the code on the calculator, but I'm a bit lost when it comes to the hardware and arduino software.

Any advice from anyone is welcomed!

Thanks

The May 2014 issue of Nuts and Volts magazine has a project to wire a TI calculator to an arduino. They have a download library and example programs.

8

Hey,

I have an arduino Uno R3, and a MEGA 2560

That article actually looks perfect!
I guess it came out recently because I have been researching this for a while.

Because I'm not a subscriber to that magazine, if you are, can you let me know if they are using the 2.5mm link cable or the USB?
Doesn't specify in the download files.

Thanks

9

booliminator:
Hey,

I have an arduino Uno R3, and a MEGA 2560

That article actually looks perfect!
I guess it came out recently because I have been researching this for a while.

Because I'm not a subscriber to that magazine, if you are, can you let me know if they are using the 2.5mm link cable or the USB?
Doesn't specify in the download files.

Thanks

They are using the 3 conductor 2.5mm cable directly wired to a arduino digital input, digital output, and ground.

10

Perfect,
Thank you for everything!

11

sorry,
One more question before I begin work.
Are any resistors used to connect the data pins or is it direct between the calc and arduino?

12

Yes, both lines use series 1K resistors. Arduino pin D7 wires to the ring connection, D8 wires to the tip and the sleeve connection wires to an arduino ground pin.