Well, over this last week I finished my version of the Ultimate Calculator. It does not have all of the fancy additions such as a mouse port, backlight, or touchpad, but I feel that these things were not really necessary for what I wanted. After asking to see what other people's ideas were on this topic: http://www.cemetech.net/forum/viewtopic.php?t=10264, I ended up taking what I was given and running with it, so to speak.

And now, I present:

A good old Ti-84+:



USB connector for recharge of batteries and use without batteries:



Powering the calculator with a solar panel:



Powering the calculator with a wall outlet:




Calculator powering a 5V regulator:


Calculator + 5V regulator powering an LED inside a halogen bulb socket:



Used in conjugation with this easy 5V regulator, you can charge your phone and other devices if all you have is your cords and no wall outlet. 🙂

Although it may not be much, it definitely solved my problems of battery usage. I guess that I could have just bought a TI-84+CSE, but hey, this is for those who don't want to spend the money.

That's a lot of ways to power a calc (In my opinion)

Yep. And a lot of ways to power other things as well. 🙂

I am wondering if it's possible to sort of integrate the solar panel onto the back and have it as another way to recharge (leave it upside down in the sun).

I could also flip the solar panel upright so that it is facing upward and use the calculator at the same time. 😁 The solar panel is on a hinge, of course.

Yeah. Then the solar panel could also be used as a stand.

I think it's almost impossible to run out of batteries on yours... Mine already has 3 times in under one year.

Mine ran out nearly every month... And now I no longer need batteries!

That is great! How does it function? Like a TI-84?

1.How much did you use it?
2. I wish I had enough skills to open my calc... I can't even fix a 4 function calculator after taking it apart.

1. Way to much...
2. It's really not that difficult; I imagine that it would also be extremely difficult if not impossible to repair a 4-function calculator, as the the processors are usually soldered and covered on the actual board. 🙂

Would it be possible for you to detail how you made this, if it's not too much effort?

I'm just afraid of breaking a cable or something, I couldn't get the keyboard membrane for the 4 function calc out so I ripped it out. That's how I broke it (plus disconnecting the lcd screen, ripping out all wires possible.

Nice job, this looks spiffy. Let me understand exactly what the electrical setup of this is, though: a USB port connected directly to the + and - lines of the calculator? If so, I have a number of concerns, not the least of which is what happens when you have normal alkaline AAAs in your calculator and connect it to a power source. If the batteries are above 5V, they may raise the voltage on the USB +V line, and if the calculator is connected to something delicate, this might not be good. On the other hand, if they are weak and their aggregate potential is below 5V, the USB may end up trying to "charge" them, with possibly disastrous results. Thanks in advance for any clarification.

Those are definitely some valid concerns! However, it is a little different than that. Here is a quick little schematic -- not a great one, but it should work.



The batteries are connected to a switch, which must be in the on position to charge the batteries. The diodes themselves are rated at a substantial DC reverse voltage in order to prevent their blowing out. In addition, there is a 5.6V zener diode in order to regulate the voltage. As with any alkaline batteries, hopefully I won't try to recharge them using anything. 🙂 And to be extra precocious, I did hook up the wiring to the actual USB a little differently, so that way even if someone tried to plug something in, it would not work. That is why it needs the separate 5V regulator in order to actually do anything. Hopefully this clears some things up; and if you notice any errors in my reasoning, please tell me before I blow up my calculator! Thanks! Kerm++

EDIT: Wow, I just realized that I had the USB as a battery... Meh, I guess that it could be; you never really know... 🙂

It could be neat if there was a way to plug in a flash drive with a 8xp or 8ck on it, and you could either run it from there or download it! However, that's a software project 😉

Check out this. 🙂

Of course, that is only for the monochrome calculators...