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RPN Scientific Firmware for the Spikenzielabs Calculator Kit
07-03-2020, 10:14 PM
Post: #31
RE: RPN Scientific Firmware for the Spikenzielabs Calculator Kit
(03-01-2016 10:19 AM)Maximilian Hohmann Wrote:  Regarding your projects I have a couple of questions and a suggestion:

- Does the housing of the Spikenzie calculator offer enough space for mounting the microcontroller in a socket? I ask because I have already "fried" a couple of them, mostly because loose wires on the breadboard got in contact with the wrong pin. And in-site-programming always comes with a certain risk of connecting the wires in the wrong order... De-soldering the controller from that calculator PCB would be beyond my capabilities.

- On one of the pictures I can see a MacBook pro, similar to what I am using. What ISP programmer and which software are you using to flash the controller in-site? And what settings do you use for bringing down the power consumption that low?

I got for myself a SpikenzieLabss Calculator Kit because I was inspired by the RPN capability (thanks to securd for sharing his code).
I bought it for $18 from it's nominal $45 price.
I didn't see it as a soldering project, and I didn't want to solder the ATmega328P on the PCB either. Instead I left it un-soldered. The chip comes with its pins flared out slightly (I skipped the SpikenzieLabs instruction step 11). I used a ruler to spring-press the pins while I was placing the chip pins into the pcb holes. At first, segment "a" was not lighting up. I bent outward the chip pin #15 and reinstalled the chip (un-soldered). It worked as advertised by SpikenzieLabs. I didn't want to solder the programming header either. I used a male 6-pin header on my FTDI programming cable and placed it in the PCB programming holes at an angle to make a contact. I programed the RPN firmware, tested it our (only 0.2uA when it is OFF) and assembled the plastics. I placed 0.5" wide Kapton tape on the LED seven segments to protect the black coating from being scratched. I was not pumped with the double sided tape on the keys. If I have an issue with the keys coming apart down the road, I will use cyanoacrylate glue.
This calculator is better than this:
I own that Sinclair piece of "rubbish" with a VFD display, which is a good reminder of the "Worse is Better" design principle.
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RE: RPN Scientific Firmware for the Spikenzielabs Calculator Kit - tarantula - 07-03-2020 10:14 PM

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