RPN scientific calculator firmware for $13 calculator kit

[DWiskow]

Could you just use a STC15F2K60S2 MCU instead of the IAP15W413AS that comes with the kit? . . . that would provide 60k of flash rather than the 13k for the standard MCU and therefore enable space for a whole raft of additional functions.

[toml_12953]

(03-18-2020 10:02 PM)DWiskow Wrote:  Could you just use a STC15F2K60S2 MCU instead of the IAP15W413AS that comes with the kit? . . . that would provide 60k of flash rather than the 13k for the standard MCU and therefore enable space for a whole raft of additional functions.

Is the STC15F2K60S2 MCU pin-compatible with the IAP15W413AS? If so, that'd be ideal!

[DWiskow]

(03-19-2020 02:14 AM)toml_12953 Wrote:  Is the STC15F2K60S2 MCU pin-compatible with the IAP15W413AS? If so, that'd be ideal!

Yes, just bigger flash (60k) and RAM (2K) and for under $2 delivered

[jklsadf]

Yes, it's a pin-compatible drop in replacement. The only disadvantage is that when programming the flash, it takes longer to erase. To program a blank microcontroller, you have to add a couple of additional options to stcgal: -l 1200 -t 12000

Just as an update, haven't made any progress on anything, but hopefully eventually...

[Paul Dale]

Some of the extra flash could be used for keystroke programs, if the base firmware is programmable. This is a very space efficient method to add functions -- the WP 34S included quite a number of functions in its XROM and allowed user libraries in flash.

Pauli

[toml_12953]

(03-23-2020 05:19 AM)jklsadf Wrote:  Yes, it's a pin-compatible drop in replacement. The only disadvantage is that when programming the flash, it takes longer to erase. To program a blank microcontroller, you have to add a couple of additional options to stcgal: -l 1200 -t 12000

Just as an update, haven't made any progress on anything, but hopefully eventually...

Now that you have all that extra space to play with, go for it! I still have my key label template ready to modify for whatever additions you make so once you announce a new version the new labels can be ready in a few minutes.

[toml_12953]

I have version 1.13 installed on two calculators. Neither one will display PI. When I press shift then divide, PI is supposed to be put in the X register but only 0 appears there.

SOLVED! In file decn.c, line 1594, there's a call to mult_decn. Why? PI is not a conversion factor so there's no need to do that. Now that I've commented out that line, the constant PI appears properly, including stack lift, etc.

One problem shows up when you do this:

7
Enter
PI
*

The display should show

0
21.9911485751285

but instead it shows

7
21.9911485751285

instead of replacing the 7 in the X register, pressing PI pushes the 7 up.

After Enter, there should be no stack lift of the next number typed.

FIXED:
Added check for Nolift to Calc.c. Now

7
Enter
PI
*

results in

0
21.9911485751285

as it should.

[MinkLib]

To make this amazing DIY RPN calculator truly portable, I converted it to LiPo so you don't have to dismantle it every 14 hours to change the coin cells. Attached is a Word doc with the details. More pictures to follow later.

Enjoy!

[MinkLib]

Here is the full 'Conversion to LiPo' article in pdf form, shrunk in size.
regards,
Chris.

[Ren]

jklsadf!!!!
Why did you post this?
Now I'm wanting one!
B^)

[MinkLib]

Here are annotated photos of the LiPo hookup for the DIY RPN calculator.
regards,
Chris.

[toml_12953]

(03-23-2020 05:19 AM)jklsadf Wrote:  Yes, it's a pin-compatible drop in replacement. The only disadvantage is that when programming the flash, it takes longer to erase. To program a blank microcontroller, you have to add a couple of additional options to stcgal: -l 1200 -t 12000

Just as an update, haven't made any progress on anything, but hopefully eventually...

Any progress yet? The new chip gives plenty of room for full-precision trancendentals, allowing degress, radians or gradians for trig functions, etc.

[gentzel]

Just a quick note that I did try using a STC15F2K60S2 as a drop-in replacement for the IAP15W413AS. No code changes, just an experiment.

It works... sort of. It's flakey. Hard to turn on, when turning off it will often immediately restart by itself, etc. But it's partially functional.

My guess is that there are timing routines or delay loops that would need to be recalibrated for what appears to be a faster processor.

[Ren]

Looking on TAS for the calculator kit
I got mixed results, (several different types , none of which seemed right to me)
Does someone have a specific link I could use?
Thanks!

Ren
dona nobis pacem

[toml_12953]

(12-01-2024 11:06 PM)Ren Wrote:  Looking on TAS for the calculator kit
I got mixed results, (several different types , none of which seemed right to me)
Does someone have a specific link I could use?
Thanks!

Ren
dona nobis pacem

Here's one. Remember, it comes as a resistor color code calculator. You have to flash the MPU with the scientific calculator firmware.

DIY Calculator Kit

[gentzel]

This is the one I ordered (though there are a lot of both AE and TAS): https://www.aliexpress.us/item/3256806645290525.html

[Ren]

Thanks for the links!
Ren
dona nobis pacem

[MinkLib]

Apologies for leaving out two references from my PDF on adding a LiPo to the DIY calculator (see 3 November post).

Here they are:
3. https://www.stcmicro.com/rjxz.html
4. https://www.amazon.co.uk/Emergencies-Por...BFDTQGIH4U
Similar versions on Ali Express for even sillier prices.

regards, Chris.