9/19/2016 – White wood mode with Gen2

Basically just going to mention a new video is on YouTube running white wood mode using Gen2 hardware.  Why it took me so long to do the rewire…I will never know.  I haven’t hooked up the switch bulb voltage yet because I haven’t received the DC to DC buck converter in the mail.  That is supposed to be in sometime next month.

Basically you can watch my poor pinball skills and laugh.  The drop target resets when the center target is hit.  Since it isn’t running any frameworks, there is no scoring, no ball counting, etc.  After this, it’s moving back onto MPF to start rewriting the rules in their framework.

I’ll try to take a quick video of the bottom of the playfield and give a quick summary of the changes.  I don’t have the energy for shooting a video and taking pictures and cropping tonight.  Sorry.  (Maybe you can tell that I’m writing this before I’ve actually shot the video.)

Hey, I did take a shot of the Cypress USB to serial port adapter and the back of the playfield.  Sorry but it is really blurry.  I hate taking videos without the camera on the tripod but I was trying to show different sections.

I also just noticed 14 people are watching the YouTube channel.  Hey, that has more followers than the OPP blog.  Weird.


2 responses to “9/19/2016 – White wood mode with Gen2

  1. I’m subscribed to both. 😀 That seems really cool that it works without code. But how are you linking switches to solenoid firings? Somehow you must be associating a switch with a coil?

    Also, I’m still struggling to see how this can be so much cheaper than Fast/Proc. Obviously there is a saving if we are making the boards ourselves and you aren’t making any money out of it. Components wise it looks like you are using less. My electronics/hardware knowledge isn’t strong enough to really see the differences, maybe more fault tolerances in the other boards? From what I see your boards seem to be able to do what the others do so I take that as a win.

    I’ll keep following progress.

  2. Each board has a static configuration. (Now I’ll link to Jeremy’s site because it is easier to point to.) http://pinballmakers.com/wiki/index.php/OPP#Firmware down in the Gen2Test subsection shows how the static configuration is programmed. (Basically each solenoid has a single switch that can be used in white wood mode). You also configure which solenoids are flippers, and which are one-shots such as pop bumpers, kickout holes, and length of the driving solenoid pulse, etc.

    Fast/PROC use much different technologies. I believe they are both based on FPGA designs. (Heck, the very first OPP hardware design was based on a Spartan 3A FPGA and I couldn’t get the costs to work out like I wanted them to.) FPGAs are relatively expensive versus hardened designs such as processors. So those chips are $8.05 on digikey right now. A nice rule of thumb to use is take the price of the parts and double them to figure out how much it costs to manufacture something. So that’s about $16 with no surrounding logic. The processor I use soldered onto the board (which includes the USB to serial interface chip) costs $4. (You’ll actually see on my costs estimates that I use $4.25 because I add tax in, because well I have to pay state tax. NH people don’t have that issue.) So right there, it is about 4 times more expensive just from the start.

    Communications, they both use differential signals. No questions in my mind that differential signals are more electrically noise resistant. I chose instead to use a UART which over-samples each signal 16 times for each bit. Y’up a solenoid fires and if you have the power wires to the solenoid tie wrapped together with the switch wire to something else for a couple of feet, you may see a single bit get swapped. Oversampling helps reject that noise, and I also embed a CRC with each message. (I have error checking on messages which I don’t think the other platforms have). Don’t run power wires in the same bundle as signal wires. Separate them as much as you can. Adding a differential signal would have added another $5 in parts. I don’t believe that it is necessary. (It’s not like this is a piece of medical gear).

    Their communication channels are really fast. (I think 1 Mbps or more). My communication channel is running at 115200 bps. If you are clever with the messages, you can get a lot of functionality out of a single command. Their commands are more generic and are human readable.

    Different choices for different people.

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