Episode 286: Logic Gate Board Game 02: Interface, Expert Advice, and LCDs

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    Karen laser cuts a prototype while Felix hot glues the light emitting diodes and solders some wire, puts in leads under the button ends, and at the end of the leads he puts in some headers. He adds resistors to each of the light emitting diodes and an NPN transistor to supply the voltage for the LEDs. Karen brings in a guest from her past who specializes in game design. He gives her some advice on making a game that's educational but also fun. Meanwhile, Ben has his hands full with one microcontroller that doesn't have enough of a breakout board and another that doesn't have enough RAM!


    Karen measures all the components to laser the face piece of the prototype.  The prototype includes 8 connector buttons for inputs on each side of the screen, 8 connector buttons for source at the top, 4 connector buttons for the results at the top, and room at the top for LEDs. Felix adds some sides to the face piece.  He hot glues the light emitting diodes and solders some wire and puts in leads under the buttons ends, and at the end of the leads he puts in some headers. He adds resistors to each of the light emitting diodes, as well as, an NPN transistor so they can supply 5 volts to the LEDs and then trigger them with a 3.3 Volt logic or whatever the logic might be.  Felix wires it up to a 3 V battery pack to trigger the green source lights. They all work.  He then triggers the red and blue Result LEDs and they all work as well.  He then hands it off to Ben to connect it to the microcontroller.


    For help with the Logic Board game, Karen enlists the expertise of JT, a proprietor of the Game Crafter, a company she used to work for.  JT works at a company that manufactures thousands of games every year, goes to dozens of conventions every year that focus specifically on game design, he’s designed lots of games including some best-selling games like the “Captain is Dead”, and has 20 plus years of experience in the industry.  According to JT, making an educational game to be something that is marketable is the hardest type of game to make.  You need to not only make it educational but you need to make it fun.  His first bit of advice is that if it’s a single player game then you need tension to be created by the game and if it’s a multiplayer game the tension is created by your opponents. Since it’s a single player game they need to come up with a tension element. You also need to make it fun. One way to do that is through engagement.


    Ben looks at a couple of LCD screens including a bigger screen which the manufacturer was kind of enough to put test pins for every signal on the back of it and even label it.  Afterwards, Ben pins it all out and removes the driver chip so he can take control of the screen. Ben looks at various PIC 32 microcontrollers before settling on a goal of just getting a PIC32 to drive an LCD screen. Ben and Felix make a breakout board for the adafruit screen. Ben uses 15 pins in his schematic. They aren’t going to be able to do 18 bits of color with the amount of RAM they have so they go with 3 bits per color.


    Ben adds switches for mode select.  There’s four bits that set how this LCD is accessed.  He puts in pull-up resistors and a DIP switch back so he can set this manually without doing it with a microcontroller. There are several modes for the LCD and they want parallel RGB. He puts several pins on it for prototyping.  The LED backlight is labeled anode and cathode whereas the screen had four parallel resistors going into the backlight. To make up for that Ben adds a larger resistor on the cathode side, which is the negative side, of the LED backlight. He’s able to turn the backlight on after doing this. Ben uses an 18 bit buff interface so it’s 0, 0, 1, 1. He hooks up a power and ground connection and then hooks up a bunch of data connection so he can attempt to hook it up to a display of some kind. Ben takes the Microchip starter dev board. It works with older units with less RAM so he hooks it up to the smaller screen. He wires directly up to the LCD pin out.  Because of the challenges with the microcontrollers he’s working on, one microcontroller doesn’t have enough of a breakout board and another doesn’t have enough RAM, Ben looks to get it running in the meantime with an FPGA.