natediggity123
Posts: 1
Joined: Wed May 15, 2019 3:19 am

Fitting a Raspberry pi into a calculator

Wed May 15, 2019 3:21 am

I was wondering if it is possible to put a raspberry pi into a calculator and use the pi as a emulator and a calculator.


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omegaman477
Posts: 148
Joined: Tue Feb 28, 2017 1:13 pm
Location: Sydney, Australia

Re: Fitting a Raspberry pi into a calculator

Fri May 17, 2019 7:23 am

natediggity123 wrote:
Wed May 15, 2019 3:21 am
I was wondering if it is possible to put a raspberry pi into a calculator and use the pi as a emulator and a calculator.
I'd use an RPI Zero.

The hardest aspects of these sorts of projects is interfacing the existing proprietary keyboard. Most calculator style keyboards are a simple crosspoint switch matrix. A keyboard of 6 rows of 4 keys, needs a 10 I/O (6 +4 = 10) lines, so it can chew up the RPI GPIO pins. I would look for a I2C GPIO extender to give you the extra I/O lines. Ti make a dedicated i2C controller chip (http://www.ti.com/lit/ds/symlink/lm8330.pdf) for the purpose. I have seen $2 breakout modules on Banggood, for 8 x 12 matrix keyboards.
..the only thing worse than a stupid question is a question not asked.

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