12C SDK projects

[tgwell2]

Hey all, new guy here!

I was just wondering if anyone had any interesting projects with the 12C dev kit/SDK that was released several years ago?

I'm definitely not new to HP calculators, but I've not had much free time the last several years... Something I've always wanted to do is try and repurpose one of these ARM based 12Cs... so this past week I finally got around to looking at it.

I'm a firmware engineer, but I don't have a 16C (though I do have a DM16... love it). So similar functionality seemed like a great first target. I've got a project going right now that does both hex and decimal bases, along with simple integer math/bitwise operations. I figure I will just continue to add functionality as I have time. I was just wondering if anybody else had anything interesting (or tips)? I'm using IAR, but I'd really love to switch to GCC... not sure if anybody has converted the dev code that was released? Also have some issues to work through on the power management or key handler side, I have to hit a couple buttons to get the screen to turn on.

Thanks!

[andylithia]

Not with the old 12C+ SDK, but I did play with the 12C+ rev2 a little bit before. I’m able to get the LCD and Keyboard working.
Checkout: https://lithcore.cn/hp12c-modding-assets/

Unfortunately, I left my dev machine at home before I come to the US. So the development is halted. The dev platform I used was simply Microchip Studio (eeeevil proprietary software)

[tgwell2]

Appreciate the link, will check it out! I currently only have the 12c+ version, have not seen a rev2. My fall back was going to be Microchip Studio.

Thanks!

[rprosperi]

(05-14-2022 08:40 PM)andylithia Wrote:  Not with the old 12C+ SDK, but I did play with the 12C+ rev2 a little bit before. I’m able to get the LCD and Keyboard working.
Checkout: https://lithcore.cn/hp12c-modding-assets/

Unfortunately, I left my dev machine at home before I come to the US. So the development is halted. The dev platform I used was simply Microchip Studio (eeeevil proprietary software)

How do you load images into a rev2 12C+ machine, the pins in the battery compartment are no longer present? Cyrille confirmed that the rev2 board does have a USB interface, but that requires cutting the plastic case to access the port and have not heard of anyone doing that successfully yet.

[andylithia]

(05-15-2022 01:10 AM)rprosperi Wrote:  

(05-14-2022 08:40 PM)andylithia Wrote:  Not with the old 12C+ SDK, but I did play with the 12C+ rev2 a little bit before. I’m able to get the LCD and Keyboard working.
Checkout: https://lithcore.cn/hp12c-modding-assets/

Unfortunately, I left my dev machine at home before I come to the US. So the development is halted. The dev platform I used was simply Microchip Studio (eeeevil proprietary software)

How do you load images into a rev2 12C+ machine, the pins in the battery compartment are no longer present? Cyrille confirmed that the rev2 board does have a USB interface, but that requires cutting the plastic case to access the port and have not heard of anyone doing that successfully yet.

The USB pogo pin interface is still there. And in my unit, the USB footprint on the PCB is still there but covered by solder mask. To access it you need to remove the solder mask with a piece of sandpaper.
And there’s also a JTAG connector footprint, covered by solder mask as well.

I basically have my unit completely disassembled to use that JTAG interface

[andylithia]

By the way. Actually, two important reasons why I didn't continue on that repurposing project is that: the rev 2 I have at hand seems to be quite rare compared to rev 1. Worse still, both models are notorious for a number of QC issues: Bad LCD flex contact, bad keyboard contact, keys stucking, and more.
Those problems can be fixed by reheating, alcohol washing, etc. But it makes repurposing very difficult for an average user compared to that on the HP20b.
As of today, the easiest way to obtain a rev1 12C+ is to search for "HP 12C for parts" on eBay. Most of those units you see with missing LCD segments are 12C+.

[java4hp]

Hello andylithia
Is it possible to repost content under https://lithcore.cn/ because it is not accessible anymore