How to trick out your TI-83 Calculator (Modification)

How to make your TI-83 Silver Edition really shine

Yesterday, I realized that my calculator was too plain and needed a little pizzazz. I own a TI-83 Silver Edition calculator which I have used throughout high school and will use through college. I decided that I could mod my calculator easily since it used standard T6 TORX and the shell was made out of frosted acrylic. Since the shell is clear, and there is quite a bit of space inside, I decided to throw in some under glow. I had a bunch of blue LED's left over from a computer case mod which I finished a year or so ago. The LED's are rated for 7.5 volts and 0.001Amperes each. First I opened the shell of my calculator and found some leads on the PCB, which I could siphon power from. The battery cage has two spring steel hinges which push against large traces on the PCB. I used those as a starting point. I measured the voltage across the board and found 6.05volts, which is normal since the calculator uses 4 AAA batteries. Mine doesn’t use any standard AAA batteries, but some high powered NIMH 800mah cells from ZUKZ. On a single charge my calculator runs for a year or so, and the LED's do not take that much power, so why not mod it.



Here is the power source traces on the PCB:


First I soldered the LED's into a simple circuit, with one fixed end, and one I could control. One of the ends was soldered to one of the leads on the battery tray. The other one was purposely left unattached. Reason being, is that I can control whether the lights are on or off on demand.



After making the circuit, I used hot glue to hold the LED's in place and to separate the leads on each of the LED's. At first I covered the LED's with hit glue to diffuse the light, but it did not work out too well, so I cleaned up the hot glue with the hot tip of the hot glue gun and my Dremel. After installing the LED's I made sure to wire everything correctly and use the smallest amount of wire possible in order to keep the inside uncluttered and clean.



After everything was connected, I made a little notch in the battery cage to run the loose wire through. The wire has a trimmed edge, so that I can simply stick the bare end of the wire between the battery and the battery cage to turn the lights on. It is a little bit tedious, but I did not want to put a switch on the side of the calculator, as I wanted it to look stock.



While I had the calculator open, I thought that I might as well make it run cooler. So I applied arctic silver thermal compound to the Texas Instruments chip. This way the chip should run cooler with the massive heat sink inside. The heat sink may look like aluminum foil, but it is what TI uses to cool the calculator processing chip. Hopefully I can install core temp on my calculator and I can see glow cool she is running





Here is the final product, and I am very proud of the hour or so that this project took:






I hope you guys enjoy this, it was a fun little project and the results are awesome

K-TRON

 

Ha, I love it! That is just too funny!

 

cool little MOD there K-TRON..... i like the choice of BLUE.... a bit more expensive,,, but CLASS is not cheap

 

Wow, pretty cool...looks almost radioactive! Almost wants me want to buy a Silver Edition, especially considering I lack a graphing calculator.

Perhaps this could become a side business? Adding LED's to people's calculators? I'm sure you could find some customers.

 

I have the silver one... i like a lot, but don't think i would do it.

PS,i think the thermal paste is excessive

 

As always...awesome job, Chris.

Kudos! Kudos! Kudos! :yes:

 

can you turn the lights on and off?...

just kidding...

its pretty sweet. how long does the battery last with the lights?

 

I don't think you want the "out of battery" prompt pop up during 3 hours long math exams. plus you probably gonna need TI-89.

 

I think I am going to be good for battery life. Typical AAA batteries are 150-175mah, and mine are 800mah each, so I can surely get more than 8-10 months of battery life per charge. A 3 hour test is no problem I have used the thing on one charge for over a year in school, which has got to be more than 30 hours of battery life. I hope I dont need to buy a TI-89, I am an architecture student, so I dont think I will be needing anything more advanced than an 83
Its a awesome calculator, and I am glad that what I have done worked out the way I wanted it to.

As far as the thermal paste, I thought: why not if I have some lying around right in front of me. Next time I may throw in a nice cooling fan, but I dont think its necessary.

I can see others like it too, the next step is to put a microcontroller inside which can be configured to make the lights flash or do tricks with one another.

I am glad you guys like it, I dont know if I should do this to other people's calcuators, cause then mine wont be as special
Anyways it was just a fun project to keep me busy,

K-TRON

 

i call BS.

that is the new texas instrument PDA. =P

jk man. pretty damn cool lol

 

lol ti-89 ftw!!

anyways, i used to own the ti-83, and its so underpowered.

But back on topic, for those people wondering about battery problems, mine can last for a year without switching out. the light shouldn't add any big significance decrease.

 

Agreed, but a cool mod nonetheless.

 

Just wait till I mod my slide rule

 

haha thats so cool. i wish i could do that with my calculator but i have a ti-84

 

You should totally try to add a backlit keypad.

 

This can't be right, because if this is right, then they wouldn't work.
You only have 4*1.2V=4.8V and the LEDs would need at least 7.5V to work, so this can't be right.

But your LEDs work, that means they will need about 3.1V, each, like almost every blue LED needs. But you run them with 4.8 V without a resistor, that's not good.

You use normal 4 800mAh AAA batteries, which are normal nowadays. That means they have a power of 3.84 Watt.

The calculator runs one year, 365 days, 21900 hours. That means it consumes 0.175 mW/h.
Your LEDs will consume min 10mA @3.1V (even special low current LEDs consume at least 1 or 2 mA. And your LED is a normal LED). You run them with 4.8V, that means they will consume min 48 mW/h each. That means they will consume min. 96 mW/h together.

Your batteries only have 3.84Watt, that means with the LEDs switched on all the time your batteries will last max. 40 hours.
You operate the LEDs at a too high voltage and they will consume more than 10mA.

Just measure it.

Sorry, but this project was crap (I think so)


edit: sorry, after reading your post a second time I saw that you connected them in series to 6V, however, they'll need more than only 1mA. The calc will last longer than I calculated but still shorten the battery life extremely.

 

Interesting MOD, K-TRON. I wonder how obnoxious it would be to sit next to you during an exam

And for all you people saying you need a TI-89... yes it's more powerful, but if you actually learn the math, there is no need for a TI-89.

 

FrankT, I am just using the values which were stated on the datasheet on the LED's. If that value is wrong, than its out of my control.
I am not an electrical engineer, I am an architect, so excuse me if my knowledge is not as high as yours.
The led's do run at a very low voltage. I have a variable dc power transformer, and the lights will come on at around 2.8volts, they are not very bright, but they come on, at 4.8V, which the power source provides, they are pretty bright, so I am not worried. I dont think I will have any overvoltage problems with the LED's cause they are in series. If they burn out, I have a bunch more which I can replace them with. I can always throw in a appropriate resistor, but I dont think I will have any problems.
It was a fun build, and it still looks stock (well when the lights are disconnected), but when the lights go out, its going down

I cant really make the keypad backlit, because the rubber sheet which fits into the buttons is a thick gray rubber, which will not let light pass through. It would be cool though

K-TRON

 

K-Tron... Only you could make a calculator cool.

I swear, you're a beast

Cool mod mate