Roger Gordon and the Newspaper and Sticker Vending Machine Projects

A coworker at LLNL contacted me in 1993 about a possible EE contracting job with a fellow who was developing a single-copy newspaper vending machine. I had some free time from my LLNL job and decided to look into the project. The project was with Roger G. Gordon who had retired as Operations Manager of a Marin County newspaper. Roger was nearly 80 years old but was pretty spunky and full of ideas and enthusiasm. And he had a lot of contacts in the newspaper business to whom he was hoping to sell battery-operated electronic newspaper vending machines. He had already patented several of his ideas for a single-copy vending machine in the 70's and 80's and asked me if I would develop a battery-operated electronic coin mechanism for his vending machines. For example see his patent US5197589. Roger designed a single copy mechanism to feed out a single newspaper at a time, preventing theft of a stack of newspapers. He already had an electronic system that had been developed for his machines but it didn't include a coin mechanism, just controls for the vending machine. It was a hardwired CMOS design and consequently was not flexible or expandable. Since I was knowledgeable about microcontroller-based systems from my work at LLNL, it seemed like a perfect application for a microcontroller. Another fellow on the project was Gerald "Jerry" Zelmer, working on the mechanical aspects. Roger, Jerry and I would meet at Johnny's Donut Shop in nearby Lafayette on Saturdays to have a donut or two and discuss the project. I learned that Roger wasn't going to pay for my work and that was the reason that my LLNL coworker had bowed out. However, it seemed promising, that we could develop a system, get some funding and start manufacturing and selling battery-operated newspaper vending machines. Later on Roger would enlist the help of Stephen D. Searle who was the owner and engineering manager of Techmetric Inc. or Techmetric Machine Works Inc., a Concord Calif. engineering and manufacturing company. Techmetric was developers of various mechanisms for hard disk drives and had several patents, such as patent no. 5423524. Techmetric's designer was Donald W. Kelsey.

For a coin mechanism for the newspaper vending machine, I designed a electro/mechanical mechanism to detect coins based on their size and for this mechanism I designed a microcontroller-based board using a Zilog Z86E21. The coin mechanism detected the different coins by their size as they slid down the coin chute. Steve Searle had one of the mechanisms machined in his shop. Below on the left shows one face of the clam-shell design and on the right is shown the "Flipper" which rotates when the coin strikes it. A small magnet on the Flipper triggers a reed switch on the printed circuit board to cause an interrupt and restart the code in the Zilog microcontroller.

Two views of my Coin Mech mechanical design.

My First Coin Mech Electronic Design.

The circuit design of my first coin mechanism is shown above. I used Eagle CadSoft to design the printed circuit board and had Teltec Corp. in San Jose etch four boards for testing. I programmed the Zilog chip using their macro assembler, developing structured macros to emulate C code. The board was bolted to the coin mechanism with a second small board with infrared LED's was mounted on the opposite side. The coins were detected by the set of infrared photodiodes shown in the middle of the board layout, illuminated by LEDs on a board mounted on the opposite side of the coin mechanism. Also for testing purposes, I purchased a Zilog Z86C21AP microcontroller evaluation board, added an Optrex LCD display module and programmed the Z86C21AP chip to acquire data from the coin mech circuit board and display the amount of money inserted. My coin mechanism and circuitry worked fairly well but occasionally would misread a dime as a nickel since the dimes would bounce a little traveling down the chute. I figured that wasn't a big problem as the coins would be returned to the customer if he tried to retrieve a newspaper and the amount of money inserted was insufficient. Then the customer could re-enter the coins and usually the coin mechanism would correctly detect the coins the second time. In the next few years I would design and build two more coin mechanism controller boards with Microchip PIC microcontroller chips and develop the code for the controller boards with the CCS C-compiler.

Roger had previously incorporated his company as UniRac and in early 2000, Roger incorporated GVA (Gordon Vending Associates) as a California corporation and we were on our way to fortunes in the vending machine business. I received 3000 shares in the new corporation work for my work and expenses that I incurred.

In about 2000, Roger conceived of a new newspaper rack design that he called The Elevator, that held the newspapers on a vertically movable shelf to elevate the newspapers, presenting a single copy to the customer. I enlisted my brother, Richard Baker (http://bakerstudio.carbonmade.com/) to produce some advertising material for Roger's Elevator and he produced the flyer idea below.

Richard Baker's Suggested Flyer Design for Roger's Elevator Newspaper Vending Machine.

Later in 2003, Roger contacted a sticker vending company in South San Jose to see if we could retrofit one of their vending machines with a battery-operated electronic coin mechanism. We were invited to meet with the principals of the company and they gave us the go-ahead and one of their machines, similar to the photo below but six columns instead of the four columns. The machine used the washing machine type coin mechanism as shown in the picture and the company was interested in changing to an electronic mechanism to keep track of sales and inventory in each of their many machines.

Sticker Vending Machine example.

Steve Searle and Don Kelsey of Techmetrics designed a new coin mechanism for the machine that used a different principle of kicking the coins off a sloping coin track to sort them to individual chutes depending on the size of the coin; quarter first then nickel, penny and dime. I designed a new microcontroller-based circuit board with infrared LED's and photodiodes to detect the coins, accumulate the coin amount and also to control a motor to operate a flap that would either accept the quantity of inserted coins or reject them in case either the customer wanted to return his coins or in case the coin amount wasn't sufficient for the sticker purchase. I don't have an image of Techmetrics' coin mechanism but an photo of my unloaded electronic board is shown below. For this design I used a PIC16F877A microcontroller chip and a low-cost C compiler for the software development. Nowadays Microchip provides a free GCC GNU C Compiler with an Eclipse IDE. Also I purchased a Sony Clie' PDA and programmed it to be able to retrieve and set prices on the coin mechanism board, to retrieve sales information and battery status via a serial connection between the coin mechanism electronics and the Sony PDA.

Controller Board for Sticker Vending Machine, Top Design and Etched Board.

There are many sources for CAD programs to design your printed circuit boards, many companies that will fab your printed circuit board and many distributors from which to purchase your electronics components. I have used Eagle CadSoft (www.cadsoftusa.com/) and ExpressPCB (www.expresspcb.com/). ExpressPCB provides free design software and will fab boards for you. Currently I am using Kicad (www.kicad-pcb.org/) since it's open source software and also I can get Gerber files using Kicad. Teltec and ExpressPCB have fabbed boards for me but I am considering using OSH Park (oshpark.com/) for my next boards as they have been recommended as providing high quality low-cost boards. I like Digikey (www.digikey.com/), Mouser (www.mouser.com/) and Newark (www.newark.com/) for components but there are many other distributors including Allied (www.alliedelec.com) and Avnet (www.avnet.com). Also I have gone direct to Zilog (www.zilog.com/) and Microchip (www.microchip.com) for microcontrollers and Maxim (www.maximintegrated.com), Linear Technology (www.linear.com), Analog Devices (www.analog.com) and Texas Instruments (www.ti.com) for various IC's. Zilog is famous for the Z80 microprocessor, of course, and I have used various versions of their Z8 chips. Also, for faster to market, I have used microcontroller boards from Z-World, now Digi International (www.digi.com), who also have an excellent C development software called Dynamic C.

Below is a photo of my controller board set up for testing.

Testing of My Coin Mech Controller Board.

The system that we (Techmetrics and myself) developed for the sticker vending machine worked beautifully to:

1. accept and accumulate the coins to allow a purchase from the vending machine,
2. reject coins if the customer wished to do so or if the amount was insufficient,
3. allow the purchase of a sticker,
4. enable setting the purchase price of a sticker for each different vending machine column,
5. provide the sales and inventory information on the Sony Clie' PDA.

The sticker vending machine company owner and others in his company were delighted at the operation of our retrofitted sticker vending machine and wanted to go ahead with a deal for us to provide more systems. We all thought we were ready to sell the retrofit battery-operated coin mechanism to the vending machine company but Techmetrics decided that their coin mechanism was not manufacturable because of tedious tweaking of the mechanical coin mechanism required to get it to work reliably. So unfortunately the deal fell thru and sadly we had to abandon the project after all the work by Techmetrics and myself. So all was for naught, but I had given the projects a lot of effort and had put considerable funds into the development, designing and building a coin mechanism, designing and programming three different coin mechanism controller boards, purchasing Eagle CadSoft printed circuit board development software, purchase-fabbing several printed circuit boards and components, purchasing the MCS and CCS C-compilers for the PIC microcontrollers, purchasing the Sony Clie' PDA and the C compiler. So at least I felt I had given much to Roger's projects and was disappointed that we weren't able to sell any systems with our designs.