If someone does not like to solder SMD, I could also offer individual assembly of the boards. I hope there is demand, and if there is I may offer a kit or the bare PCBs.
![ti 84 emulator software linux ti 84 emulator software linux](https://hackaday.com/wp-content/uploads/2014/12/proto2-1.png)
I guess I can already warrant a sneak peak at the keypad matrix The Uno is also connected to the 128圆4 screen and will go into high impendance mode to let the Pi access the screen, once the Pi is booted and ready.
Ti 84 emulator software linux serial#
Otherwise, the serial console will be displayed on boot in a serial terminal mode of the Uno. You should be able to reflash the Uno from the Pi, if you disable the Linux console on the serial port. The Uno is connected to the Pi via SPI and UART. The headphone/Link jack will either expose the Pi Zero's analog video signal plus one GPIO pin or the I2C bus, depending on solder jumper configuration.
![ti 84 emulator software linux ti 84 emulator software linux](https://www.maketecheasier.com/assets/uploads/2012/07/ti_emulator-tilem_config.jpg)
Therefore you can decide whether you want to provide your own single board computer or if you want to go for a Pi Zero and my preferred, matching LCD. The bottom half of the board (including keypad matrix, RTC, Uno and the Adafruit PowerBoost500 for LiPo operation) will be attachable to the upper board through a few solder links. On the upper board, there is space for fitting a Raspberry Pi Zero (W) and a 128圆4 monochrome/grayscale LCD that I would provide.
![ti 84 emulator software linux ti 84 emulator software linux](https://i.ytimg.com/vi/1I_1KLw_0hk/mqdefault.jpg)
There will be an upper and a lower board. It features an ATmega328P-AU Arduino Uno compatible keyboard processor and power management controller and real time clock (to keep the time running, while the Pi is turned off). You almost can't differenciate the original from a modded one. This will enable you to build your completely own, Linux powered, TI-84+ I have been very busy lately, developing a complete replacement main board that will fit into the empty shell of a TI-84+.