Hello! Super excited about the Arduboy. I was looking for plans to build a simple button board around my favorite dev kit, the D1 mini, that my kids could learn to program on when I discovered Arduboy instead.
I went right to building a homemade system on breadboard using a bare 32u4, SPI OLED and flash cart. I used a combination of Billy Cheung’s ArduBaby schematic, MyAlexro’s EasyEDA design and the official schematic. One exception: I am powering the whole board from a USB breakout. Trying to minimize the power circuitry and use removable USB power banks.
I uploaded a bin of games using Mr. Blinky’s Python scripts and I burned the Cathy3k bootloader using an UNO as ISP.
My problem is, everything works fine as long as I drive the homemade system using the UNO as ISP. Once I disconnect it and apply power to the USB breakout, the system gets stuck at the USB boot mode. Pressing A or B drops me to the last game I was playing but I can’t get back to the menu unless I re-attach the UNO and disconnect the USB.
One thing of troubleshooting I did was to pull the UNO one wire at time and it seems like the SCK line is the one that, if connected, allows the system to boot to menu instead of the USB boot symbol.
I’m thinking the Cathy3k has some logic to detect a device on USB and is preventing the system from booting to menu or I just have something wired wrong. Any suggestions?
Thanks so much for the help.