Comparing Android apps for the hp15c

[Johnh]

What a great couple of weeks its been for the world of RPN calculation! Just about every current model has had an upgrade with firmware, or apps, or both, across both HP and Swissmicros.

I’m interested in HP15c and its family, and I was happy to see the HP15c-CE updates and the official HP15c Android app available again as announced yesterday. So I decided to get the re-released App and compare to others for the ’15.

I think that having an App on a phone, that corresponds to a real calculator, enhances the use of each. The App can act as a test bed for the calculator, and works better in low light and for when you don't want to get the real calculator out. Having the two based on the same design allows familiarity to develop. Hp15c-CE is the one I reach for now, so I wanted to make sure I have the best available App to go with it.

For Android, I think there are currently three available Apps that aim to match the look and user experience of a real HP15c, being the official HP one from Moravia, TouchRPN from Stendec and JRPN15 from Jovial.

All can be massively faster than the original ’15, so that's not really a point of comparison. In terms of cost, the HP app is the most expensive, TouchRPN is less than half, (or free if ad supported), JRPN is free. But really, for the thousands of hours that went into the original design and the coding of these apps, and for what you get, I think $ are minimal.

I set each one up on my S22, with settings chosen to optimise each one. This phone is only about 85% of the width of a real Voyager, although it is quite long. So to get the fullest view, it’s the width that constrains it.

Appearance

See screenshots below.

HP15c from Moravia

Out of the three, this one looks to me to be most like the real thing with its Hewlett-Packard and HP15c logos, details of keys and bezel with shading and shadowing and a metallic look to the bezel and deep tones for the keyboard body with realistic colours.

The full calculator with bezel and logos is fitted to the available screen, which also shows the general phone info such as battery, connections, time etc. So the calculator working area is compressed to suit, at least on my S22.

Touch RPN

This also has a 3D look, but it’s a bit more simplified, slightly less realistic than the HP, not quite as deep a background tone, and a bit lighter LCD. This may actually make it a bit clearer in use. Most usefully, settings can suppress the background phone info and also trim the bezel to get the maximum full screen expansion of the working area. Hence it looks significantly bigger for keys and digits, approaching full size.

JRPN15

This one also shrinks the calculator with the full bezel, similarly to the HP, but digits are a bit smaller again. Graphics are clear and 3D, fairly similar to TouchRPN and less real than HP. It has a nice feature though, whereby you can adjust RBG colour-codes for the key and label tones. So I boosted the f and f-reference colours to make them less red and brighter and more golden, similar to my HP15c-CE.

Feel and feedback

All offer sound and haptic feedback, and TouchRPN can also set a slight glow on key pressing. I found the haptic feedback on TouchRPN to be the best, with a clear solid thump, the best representation of a HP key I've felt in an app. The Moravia app is fine for haptic, but is more subtle. I cant get the JRPN feedback to work, probably a phone setting needs adjusting.

Portrait mode

All offer portrait modes and these are very useful on a phone app. For TouchRPN and JRPN it’s a fully-featured transposition of all the keys (slightly different to each other). However, in portrait mode the HP app goes to a stripped down 4-function RPN calc. I could see that has its use for quick numbers. I wish it just brought over a bit more of the full set though, particularly the ability to enter powers of 10 without having to go back to landscape.

Key codes and output.

JRPN15 can copy the program listing to the clipboard, with line numbers, key codes and key names, which is very useful. TouchRPN also works with the text file, if you find it, but doesn’t do key names to date. I didn’t any see such features offered in the HP app. Also TouchRPN and JRPN can save states within the phone, which I didn’t see on the HP App.

One more difference is that TouchRPN creates key-codes which include the label letters A to E, where called up as labels. That could actually be a good feature in principle, but of course it's not as per the original.

Wish list…

I think the ideal would be:

1. Trim and stretch the display like TouchRPN, suppressing phone information to maximise the working area
2. Program code text output as JRPN
3. Save states as JRPN and TouchRPN, very useful for testing
4. Graphics like the official HP app, maybe with a tad lighter LCD
5. Stretch wish…. Connectivity compatibility with HP15c_CE windows app and firmware for program transfer from the real calculator to the pc to the App.

Sorry if I missed or misrepresented anything, and thanks for reading!

John