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For Want of a Pin the Project Remains Thus Far Unfinished

A project log for Think-a-Tron 2020

In 1960 Hasbro unleashed its first personal "computer" to the masses, decades before IMSAI, Apple, or Commodore. Remembering Think-a-Tron.

Michael GardiMichael Gardi 01/23/2021 at 21:300 Comments

I'm coming down to the wire, literally, for my Think-a-Tron 2020 project. The anticipation is killing me but I have a couple of small problems. For one I'm a pin short.  I thought I was OK based on the documentation I had on hand.  This was my plan.

ESP32-CAM PINThink-a-Tron 2020 Connection
GPIO 0 Not Available Camera XCLK
GPIO 1Trigger Sound Effect
GPIO 2Player 1 Answer Buttons (ADC)
GPIO 3NeoPixels (all 45 of them)
GPIO 4Camera LED
GPIO 12Score Counters SDI
GPIO 13Score Counters SCLK
GPIO 14Player 2 Answer Buttons (ADC)
GPIO 15Score Counters LOAD
GPIO 16? Button ***

The problem is that GPIO 16 is in fact used by the Camera although this is not documented anywhere I could find. Any use of GPIO 16 causes the camera to crash when capturing an image (sigh).

The other issue is that the analog readings that I am getting from the player inputs suck. Even averaging multiple analog reads sometimes results in the wrong button being "selected".  

So I have ordered a 16 bit high precision 4 channel I2C IIC Analog-to-Digital Converter based on the ADS1115 PGA ADC converter chip (Amazon). 

So in a couple of days I'll see if I can convert two pins for an I2C bus into 3 inputs: Player1, Player2, and ? buttons. Hopefully I can kill two problems with one piece of silicon.

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