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OT: new ebook: Build your own programmable calculator - Printable Version

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OT: new ebook: Build your own programmable calculator - Karl-Ludwig Butte - 05-30-2008

For all German speaking forum members it may be of interest that Elektor-Verlag just published a new ebook "Programmierbare Taschenrechner selbst gebaut" ("Build your own programmable calculator"). Just follow this link: http://www.elektor.de/elektronik-news/programmierbare-taschenrechner---selbst-gebaut.509623.lynkx for all the details.

Regards

Karl


Re: new ebook: Build your own programmable calculator - Walter B - 05-30-2008

Hallo & thanks for the link. Note that "UPN" (i.e. RPN) is mentioned explicitely in the abstract of this e-book. So I removed the "OT" in the subject ;)


Re: OT: new ebook: Build your own programmable calculator - DaveJ - 05-30-2008

It's hard to make out form the photo, but what kind of keypad is that? membrane or buttons?

Dave.


Re: OT: new ebook: Build your own programmable calculator - Walter B - 05-30-2008

Quote:
It's hard to make out form the photo, but what kind of keypad is that? membrane or buttons?
For me, it *looks like* a matrix of square standard buttons used for setting up bigger electronic devices for some 20 years at least.

Walter


Re: new ebook: Build your own programmable calculator - Hubert Weikert - 05-30-2008

Was too tempting, therefore I bought the book...

The book describes several diy calculator models.

The first one is a two chip LED calculator based on the old (nineteen eighties) MM5738 chip (four banger).
The keys are, as with all calculator models in this book, single switches, available in Germany at this site: Buttons

The second model in the book is a programable LED RPN calculator based on the (also old) MM5760N and MM5765N chips. These chips provide the functionality of a simple scientific calculator.

The third one is programable LCD RPN calculator with the Parallax BASIC Stamp (BS2p24) as core. The description, users guide and programming examples cover about 200 of the 259 pages of the book. Examples show how to use the two analog inputs (separate ADC chip) and four digital outputs of the BASIC Stamp.
The user level programming looks like standard HP RPN, with extension for the additional functions. The display is a two line alphanumeric LCD with 16 characters per line.
The BASIC Software of this RPN calculator and a alernative algebraic entry version is freely downloadable from the elektor site.

The book contains component and circuit descriptions, printed circuit layouts and parts lists. The software chapters cover the BASIC algorithms used for the scientific functions, and several examples of RPN programs illustrate the use of the RPN calculators.

So much for the first impression,

Hubert


Edited: 30 May 2008, 2:00 p.m.


Re: new ebook: Build your own programmable calculator - Karl-Ludwig Butte - 05-30-2008

Thank you all who have responded, especially Hubert for the first description of the contents. I'd like to use the opportunity to get your opinions, if there's a market today for special-purpose calculators e.g. like the author suggested, with two-channel voltage measurement for electricians. Other combinations could be with CAN-Bus-Interface and/or datalogger for technicians in the car industry, etc. HP tried something like that with the HP-97S and of course the HP-IL. But today notebook computers are everywhere, providing that much more functionality. So what do you think: Would people prefer smaller but more specialised devices or would they rather use their notebook computers ?

Regards

Karl


Re: new ebook: Build your own programmable calculator - Donald Williams - 05-30-2008

Would people prefer smaller but more specialised devices or would they rather use their notebook computers ?

It is not a matter of preference for the instance of control.

Calculators do not have controller capability. The last calculator that I know of that had any decent controller capabilty was the HP-41.

The USB ports on modern calculators are only capable of communicationg with a PC. They can't control anything.


Re: new ebook: Build your own programmable calculator - Egan Ford - 05-30-2008

Quote:
The USB ports on modern calculators are only capable of communicating with a PC. They can't control anything.

My 50g has a serial port. It's modern and can control things too.


Re: new ebook: Build your own programmable calculator - Donald Williams - 05-30-2008

Agreed. I do the same, but those are all legacy devices. I haven't audited all possibilities, but I also haven't seen anything produced with a serial port connection in the last 3 years. With few exceptions modern devices are supplied with USB ports not serial ports. The USB ports on calculators do not have controller capability. The TI 89 has USB OTG which is only slightly better than none.


Re: new ebook: Build your own programmable calculator - DaveJ - 05-30-2008

Quote:
Would people prefer smaller but more specialised devices or would they rather use their notebook computers ?

It is not a matter of preference for the instance of control.

Calculators do not have controller capability. The last calculator that I know of that had any decent controller capabilty was the HP-41.

The USB ports on modern calculators are only capable of communicationg with a PC. They can't control anything.


My uWatch can control stuff, just add firmware and the interface of your choice. It would be trivial to add any control capability desired into a DIY calculator.

And TI do a range of data collection calcultors:
http://education.ti.com/educationportal/sites/US/productCategory/us_data_collection.html


Dave.


Edited: 30 May 2008, 6:31 p.m.


Re: new ebook: Build your own programmable calculator - Donald Williams - 05-30-2008

And TI do a range of data collection calcultors: http://education.ti.com/educationportal/sites/US/productCategory/us_data_collection.html

Once again the USB OTG limitations rear their ugly head. The calculator can only control one device at a time. It cannot connect to a USB hub. Nothing like the capabilities of HPIL or the HP 41.


Re: new ebook: Build your own programmable calculator - Karl-Ludwig Butte - 05-31-2008

Thank you all who have responded so far to my question if there's a market for specialised calculators with I/O-capabilities. But reading through your comments I got the impression you discussed the possibilities of devices available today. But I meant future devices that are not available today. So I'd like to ask my question again: Would people like to buy specialised calculators with I/O-capabilities and/or controller capabilities like HP-IL ? With the ebook by elektor as a startingpoint such devices could be developed. But such a device could only be mass produced, if there's a big enough market for it. What do you think ?

Regards

Karl


Re: new ebook: Build your own programmable calculator - Donald Williams - 05-31-2008

Just my thoughts on the matter

I think your hypothetical calculator-controller might be competing in these 2 market segments

Laptops and embedded controllers

So what might be its potential advantages be?

1. Small form factor - smaller than a laptop
- embedded controllers can be very small

2. Longer operating time - better than a laptop
- embedded controllers can have really small power requirements

3. Price - should be cheaper than a laptop hardware & software
- Embedded hardware is cheap, but programming labor costs are expensive

4. Programming - Requirement- should (must) be easier to program than a laptop
- Requirement- should (must) be easier to program than an embedded controller

5. Communications ? - Modern Laptops are usually limited to USB or 1394
- Embedded controllers have many protocols

Items 1, 2 & 3 are what they are. So I think you would have to pay paticular attention to Items 4 and 5.
If you could create a programming enviroment similar to, and as robust as, HP-41 RPN and HPIL then you
would have a winner. 100 lines of RPN/HPIB was the eqivalent of 1000 lines of C and less likely to have
bugs. Communications is problematic. The real reason USB controller capability is absent on calculators
is that it really doesn't make much sense. USB communications is going to suck the life out of the
calculator batteries in a very short time. HPIL was invented for this very purpose, but unfortunately
it is proprietary and will likely remain so.

I wish I could read German.

(I apologize for the formatting of the post. I know it was hard to read but I couldn't make it look any better)


Edited: 31 May 2008, 7:31 p.m.


Re: new ebook: Build your own programmable calculator - DaveJ - 05-31-2008

Quote:
Thank you all who have responded so far to my question if there's a market for specialised calculators with I/O-capabilities. But reading through your comments I got the impression you discussed the possibilities of devices available today. But I meant future devices that are not available today. So I'd like to ask my question again: Would people like to buy specialised calculators with I/O-capabilities and/or controller capabilities like HP-IL ? With the ebook by elektor as a startingpoint such devices could be developed. But such a device could only be mass produced, if there's a big enough market for it. What do you think ?

What sort of "controller" capabilities?

To cover all bases these days you'd (seriously) need RS232, USB, RS485, CAN, Ethernet (Internet), IrDA, Bluetooth, Zigbee, WiFi, RFID, and GSM mobile phone options etc.

Note that I left out HP-IL in that list, it's just not an interface that anyone would seriously consider these days.

I've designed countless industrial devices that use all sorts of flavours of the above "control" interfaces, not to mention custom stuff. I've even been involved in the design of a hand held controller of sorts that has all of those interfaces built in. See the hand held device in the video here (not on the market yet):

http://www.altium.com/summer08/

A controller is nothing more than a bit of hardware with the appropriate hardware interface, appropriate user interface, and the appropriate software.

As I said, my uWatch is a product available now, and you can customise it to have have some basic interfaces, and then write the software you want.

There would be almost a ZERO commercial market for a calculator/controller. They are just two things that really don't need to be combined.

Hand held calculators exist and there is a big market.

Hand held controllers exist and there are big more specific markets for those.

The more you combine the two the more you compromise in all sorts of ways.

If anything, the current hand held PDA *is* almost exactly what you want - just add software and any appropriate hardware interface by way of compact flash expansion cards etc.

And considering that most products that require control will already have a PC based control application available, the only sensible option for a hand held controller is a pocket PC. So that the large software investment can be leveraged.

Dave.


Edited: 31 May 2008, 7:48 p.m.