Re: Arduino HP-25 Simulator

[Maximilian Hohmann]

Hello!

(03-23-2022 03:28 PM)TellyS Wrote:  Nigel, from the forum, suggested this library: Big Numbers on Arduino, that seems to provide more accuracy than I could ever imagine.

Yes, but... the BigNumber library does not come with transcendental functions (I know this because I used it some time ago for a project). You will have to add them yourself. In the examples section they only provide code for the sine function, and this is probably very slow.
Maybe Teenix's approach will be less tediuos in the end and will certainly result in something more similar to the original HP-25.

Otherwise an interesting project and you really made the best of the display concerning the graphic rendering of the calculator.

Regards
Max

NB: They have been out of production for some time, but some years ago the company "Micromega" sold a 64bit FPU for use with microcontrollers such as the Arduino, called "uM-FPU64". It could be accessed using the I2C bus, thus requiring very few connections. I don't know if they can still be found somewhere, but this may also solve your accuracy problem.