#include <hid.h> // https://www.usb.org/sites/default/files/documents/hut1_12v2.pdf // section 10, page 53, table 12 char keycodes[] = { 0, 0, 0, 0, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '\n' }; REQUEST(doKeyCallback, "ioManager", "keyCallback"); void handleKeyboard(uint32_t usage, int32_t data) { if (usage == 0) { return; } if (usage >= sizeof(keycodes) / sizeof(char)) { // doKeyCallback('E', 0); } else { doKeyCallback(keycodes[usage], 0); } }