FRITZING, CHINAand the

NP25 CALCULATOR

Presented by: Jim JohnsonHP Handheld Conference 2015 – Nashville, TN

September 26-27, 2015

FRITZING, CHINA and the NP25

Synopsis: The NP25 was developed by Chris Chung and used Eric Smith’s Nonpareil code. Chris developed a small pc board calculator that can emulate the HP21, HP25 and the HP33 calculators. He placed the code, the gerber files, the schematic on Github and it is an open source project that anyone can make. There is a moderate amount of interest in receiving the NP25 as a finished device, or as a kit. In February of 2015 I contacted Chris after he had mentioned that he would stop making the NP25 himself and so I picked up where he left off and began making fully assembled NP25’s and kit NP25’s.

This discussion is about sharing the pc board layout program that was used in developing the NP25. It show’s the simplicity and flexibility of pcb design. The process of ordering parts directly from China and the steps of assembling the NP25.

FRITZING, CHINA and the NP25

LIVE DEMONSTRATION! Always be aware of your soldering iron position in relationship to other combustible, scorching, searing, sizzling objects (such as fingers, arms, paper, plastic, close friends and relatives.

A WORD OF

FRITZING, CHINA and the NP25

What is Fritzing?

Fritzing is an open-source hardware initiative that makes electronics accessible as a creative material for anyone. They offer a software tool, a community website and services in the spirit of Processing and Arduino, fostering a creative ecosystem that allows users to document their prototypes, share them with others, teach electronics in a classroom, and layout and manufacture professional pcbs.

You can access Fritzing at: http://fritzing.org/home/

FRITZING, CHINA and the NP25Creating a Printed Circuit Board

FRITZING, CHINA and the NP25Ordering from China

Ordering parts from China is simple and easyWith eBay and PayPal. The pc board was ordered from ELECROW in China. Ten (10) pcb’sfor $12.00 total. Delivery, from Gerber files being sentto delivery at your door can be in as little as 6 daysusing DHL.

FRITZING, CHINA and the NP25Ordering from China

Ordering resisters, capacitors, switches, battery holders, batteries, LEDs, etc. is as easy as searching inside of eBay for Chinese suppliers. And most of them SHIP FREE for small quantities!

FRITZING, CHINA and the NP25

Assembling the NP25LIVE DEMONSTRATION

FRITZING, CHINA and the NP25

Summary and Conclusions

• The goal of this presentation was to share information on the Fritzing pc board layout and design application. • Show that ordering parts from China shouldn’t be daunting, confusing or difficult.• Give a quick tutorial and live demonstration on assembly techniques when assembling the NP25 pc board calculator.

FRITZING, CHINA and the NP25

Acknowledgements

1. Eric Smith – Eric’s excellent work on NONPAREIL and the High-Fidelity Calculator Simulator.

2. Chris Chung – NP25 hardware and firmware development.3. Museum of HP Calculators – (http://hpmuseum.org)

FRITZING, CHINA and the NP25

Thank you!

© All rights reserved regarding the information contained in this presentation . If you have any questions you may contact Jim Johnson. Email: jjohnson873@yahoo.com