Smart Response XE

Smart Response XEs are one of those handheld electronic student answer things used by schools. It's been discontinued for a while, and there a bunch out there on eBay for pretty cheap (~$5-$8)

What makes these nice is that they have a big graphical LCD and a qwerty keyboard. The microcontroller is an atmega128rf, which includes 2.4ghz radio hardware (zigbee or similar), as well as 128K flash, and 16K ram.

I bought a few the last time they were featured on Hackaday. These were poised to be the next IM-Me style hacked device, but I haven't seen that much development on them (just a couple in 2018-2019). Perhaps that's because there isn't a whole lot of information about them.

Software

The system is almost directly Arduino compatible, we just need to figure out a few things about the hardware.

Board/core

Sparkfun released a dev board several years ago with the Atmega128RF on it. We can use the hardware definitions they provided - see https://learn.sparkfun.com/tutorials/atmega128rfa1-dev-board-hookup-guide for both the software and the pin definitions

LCD

The u8g2 lib supports this screen/controller - https://github.com/olikraus/u8g2/wiki/u8g2setupcpp#st7586s-s028hn118a

Configuration for SW spi and the other control pins is:

U8G2_ST7586S_S028HN118A_1_4W_SW_SPI u8g2(rotation, clock, data, cs, dc [, reset]);
U8G2_ST7586S_S028HN118A_1_4W_SW_SPI u8g2(U8G2_R0, 13, 11, 7, 24 ,18);

HW SPI works too, you just don't need to specify pins 13 and 11 (clock and data).