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DIY electronic Speed test

A DIY replica of electronic speed test game, manufactured by Coinline in Finland. A similar game is also manufactured by DPS-Promatic in Italy. These games became very popular in Finland in 90s because they were part of a tv-show competition. The speed test game is still fun and addictive. You must press the buttons as they lit up. The speed gradually increases. See links to videos from below to understand how it works.


See this youtube video of the game in action. Another video which has the latest version of electronics.


The circuit is based on PIC16F15355 micro controller. Piezo buzzer and button lights are driven with ULN2003 Darlington array. 7-segment display is driven directly from micro controller pins. It is possible as long as the used display has high efficiency LEDs. The display types listed in BOM work well. Switches connect to ground and their readout uses PIC internal pull-ups.

The PCB uses only though-hole components so it is easy to build by beginners. It is 2-side PCB with plated through holes so it is easiest to order the bare PCB from factory. See below section Getting parts. The board has screw terminals for connecting wires. It is advisable to solder the screw terminals to bottom side of board, so you have easy access to those even when the board is attached to front panel of enclosure.

nopeustesti_v1_circuit_diagram.pdf Circuit diagram
nopeustesti_v1_assy_and_bom.pdf Assembly drawing and bill of materials
nopeustesti_v1_hw.zip PCB design files, made with Eagle 5.12.0
nopeustesti_v1_gerbers.zip Manufacturing files in Gerber 274-X format
nopeustesti_v1_idf_and_step.zip 3d-model in IDF and STEP formats


Firmware source code and compiled .HEX available below. Compiled with CCS compiler version 5.081.
nopeustesti_v1_fw_v09.zip (22.8.2019)

Getting parts


I have used case aluminum enclosure Hammond 1550J. Design mimics the features of original game.

Enclosure with holes waiting to be painted. Holes were made with milling machine. Artwork will be placed under transparent PC sheet which is fixed with mushroom head bolts as in original.

Painted enclosure and parts which will go inside. Picture above shows 60 mm arcade buttons, but you can use smaller ones. The original game uses 45 mm buttons.

Rear panel has power switch and IEC mains connector with integrated fuses.

Inside view. I really recommend to use external, approved mains supply and not place it inside the enclosure. When there's only +12V DC voltage in the enclosure the risk of electric shock is greatly reduced. Picture above still shows old version of electronics which is split to two boards.

Finished game. You can download the artwork below in .pdf format by clicking the picture. Original Inkscape svg -file available here. The used font is K22 Xanthus.

Modifications and improvements

If  you are using adjustable power supply, you can set the voltage to slightly higher, ca. 13.2 V. This way you can get full 12 V to button lights, because the reverse protection diode D1 and Darlington array ULN2003 will cause ca. 1.2 V voltage drop. Alternatively, you can replace D1 with Schottky -type e.g. 1N5815 and IC2 with MOSFET -type e.g. TBD62003APG. You could even replace D1 with just jumper wire but then you must be careful about correct polarity. However, difference of one volt is not significant to button illumination brightness. The used LED type has much bigger effect, see below.

You get better contrast to score display if you use red or smoked display lens. It also makes display easier to read in daylight.

The micro switches delivered with the big arcade buttons are usually crap. The are stiff and have poor contact. It is advisable to replace those with quality, low force micro switches. E.g. 75 gram Cherry switches or 50 gram E-Switch switches work well. With these, a skilled player can easily gain tens of points to high score.

Also the LEDs delivered with arcade buttons are usually quite dim. Good in dusk, but in daylight they could be brighter. I have tested many types of LEDs and so far best have been 'bevinsee' branded LEDs from eBay which should look like this. You get best results when you use same color LED as the button color. When using while leds the color will be pale.

kair.us/ projects/ nopeustesti/

page created 7.8.2013
last updated 30.8.2019 webmaster@kair.us