Folks,
Next is the internal guts. I refuse to organize my wiring, as I am still tweaking the insides. So excuse the mess.
Shown here is my rats nest of all my electronic goodies inside my machine. On the left and right side you can see my vibe motors. In the middle is a 6″ subwoofer. in the foreground of the subwoofer is my open chassis audio amp delivering Class A/B 2.1 sound. On the right front is my plunger system. This is a kluge and will be replaced with a PLA 3-D printed assembly. In the rear you can barely see my compact size Lenovo PC which can be had for ~$70 (used with Win 7). I upgraded the CPU for 3.1GHz and up the DDR3 memory to 4 gigs. Last I tossed in a HD6450 video card which is more than adequate for a non-moving table.
Note
I have read people recommending faster CPUs and video cards. I can vouch that the video card is not causing any performance problems. However, on some of the more demanding games I am experiencing some audio stuttering when playing some of the more intense games. I am still looking into this.
Audio and Subwoofer
During experimentation I went through 3 subwoofers and four amplifiers in attempting to best my first cabinet attempt. I eventually settled on an open chassis, low-power, with a three channel amplifier driving a 6 inch woofer. The two 4” coaxial front speakers remained, as these sounded great and were relatively cheap. The complete audio section was only ~$45, as long as I am not driving it beyond 5 watts it can stand up to the best and still come out as a close second. I am in-process of exchanging audio amplifiers again. This time I am going forward with a 24V Class D audio system that provides 20W @ under .1% THD and a bridge amp for subwoofer rated at 40watts @.1 THD. I am currently composing an audio guide that discusses all audio options for virtual pinball. I urge all to read it, as it will have some great information.
Haptics using Audio and DOF
Haptics (tactile feedback) is still eluding me. I placed two DOF controlled vibe motors close to the flipper buttons. When activated, the rumble can be felt, but my subwoofer can almost reproduce this effect too. The knocker sounds realistic using a cheap $9 solenoid from one of those Arduino supply sites. I have concluded that using superior wave files and an optimized speaker system can faithfully reproduce 90% of all the sounds and feel of real pinball.
To fill the gap further, I am now experimenting with audio exciters thanks to “Poor man’s DOF article I read on the Aussie pinball boards”. Exciters are sound transducers that use a mounted surface to transmit sound instead of air. This results in an increased tactile response. The problem with my setup is that my vibrations are not rich in low vibration. I attribute this to my audio amplifier having a built-in 3 dB cross over at ~240 Hz. So to make these exciters fully effective, I need to upgrade my amplifier. Exciters are best for reproducing playfield events such as ball bounce, roll, and solenoid. Amazon has a full line of Dayton Exciters. Mine was only $9 on Amazon.
Plunger
My current plunger works with a linear 10k potentiometer that is both cheap and effective. Mike Roberts, author and designer of the Pinscape suggest using his CCD linear array. I remember Mike posting his research on You-Tube a few years ago and I am happy that he has finally perfected it. The CCD linear array is great, as the only moving part is the plunger that is used to progressively interrupt a light source white it is being pulled. Unfortunately, the CCD linear array is cost prohibitive for my project. I attempted to use a smaller and cheaper CCD solution, but complications of the increased optics made this idea impractical. I also played with a variable reluctance system, but it was not stable and became too complicated to implement. I am currently researching an alternative solution using an Adafruit VL6180X Time of Flight Distance Ranging Sensor (VL6180). This solution is slightly more expensive than the linear potentiometer, but should offer the same performance as the Mike’s CCD array at half the price. Provisions for I2C interface and applicable coding will need to be mitigated into the next version of the Bang! Board and into the Pinscape firmware. As mentioned this is still in the research stage.
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