[Keyboard] Add Budget96 by Donut Cables (#5550)

* initial commit of budget96

* non logic changes

* add my name to readme

* update matrix.c

* make the matrix representation of the layout macro

* fix up LAYOUT macro

* add missing character

* initial keymap commit

* put KC_NO where they belong

* basic keymap

* fix matrix row and col definition

* The diagram I was sent and the pins used I was sent were in opposite order from each other. This should fix the issues

* update the readme

* change up manufacturer for budget96

* update copyright date

* fix up the switch matrix and provide a keymap

* forgot the keymap

* other matrix fixes

* missing a few keys in the switch matrix

* messed up the row tracing

* tweak keymap a bit

* use a lower case k

* fix spacing for markdown rendering

* put in the reset key documentation

* clean up the file a little

* use LAYOUT_96_ansi

* add a second layer for lighting controls

* add in lighting support

* add QMK Configurator support

* use pragma once

* remove un needed matrix.c

* convert to GPIO methods

* turn on rgblight_enable and get rid of custom matrix

* set bootloadhid_bootloader to 1

* set bootmagic to lite and set it to k50

* add reset information to readme

* use i2c_master instead of custom i2c

* restore the custom i2c code

* introduce reset key and eep_rst in function layer 1

* fix up pip3 install commands

* fix up device and manufacturer names

* remove un needed comments

* add an ALL layout macro along with QMK Configurator support

* move budget96 into donutcables directory since he actually has different boards

* add a short donut cables blurb taken from his website

* update readme for make instructions to point to the new path

* Update keyboards/donutcables/budget96/config.h

Co-Authored-By: mechmerlin <30334081+mechmerlin@users.noreply.github.com>

* Update keyboards/donutcables/budget96/readme.md

Co-Authored-By: mechmerlin <30334081+mechmerlin@users.noreply.github.com>

* Update keyboards/donutcables/budget96/info.json

Co-Authored-By: mechmerlin <30334081+mechmerlin@users.noreply.github.com>

* turn on backlight

* Update keyboards/donutcables/budget96/readme.md

Co-Authored-By: mechmerlin <30334081+mechmerlin@users.noreply.github.com>

* remove extra UART and BOOTLOADER settings that are not needed

1 files changed, 106 insertions, 0 deletions

diff --git a/keyboards/donutcables/budget96/i2c.c b/keyboards/donutcables/budget96/i2c.c
new file mode 100644
index 000000000..e8c4455ad
--- /dev/null
+++ b/keyboards/donutcables/budget96/i2c.c
@@ -0,0 +1,106 @@
+/*
+Copyright 2016 Luiz Ribeiro <luizribeiro@gmail.com>
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+// Please do not modify this file
+
+#include <avr/io.h>
+#include <util/twi.h>
+
+#include "i2c.h"
+
+void i2c_set_bitrate(uint16_t bitrate_khz) {
+    uint8_t bitrate_div = ((F_CPU / 1000l) / bitrate_khz);
+    if (bitrate_div >= 16) {
+        bitrate_div = (bitrate_div - 16) / 2;
+    }
+    TWBR = bitrate_div;
+}
+
+void i2c_init(void) {
+    // set pull-up resistors on I2C bus pins
+    PORTC |= 0b11;
+
+    i2c_set_bitrate(400);
+
+    // enable TWI (two-wire interface)
+    TWCR |= (1 << TWEN);
+
+    // enable TWI interrupt and slave address ACK
+    TWCR |= (1 << TWIE);
+    TWCR |= (1 << TWEA);
+}
+
+uint8_t i2c_start(uint8_t address) {
+    // reset TWI control register
+    TWCR = 0;
+
+    // begin transmission and wait for it to end
+    TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN);
+    while (!(TWCR & (1<<TWINT)));
+
+    // check if the start condition was successfully transmitted
+    if ((TWSR & 0xF8) != TW_START) {
+        return 1;
+    }
+
+    // transmit address and wait
+    TWDR = address;
+    TWCR = (1<<TWINT) | (1<<TWEN);
+    while (!(TWCR & (1<<TWINT)));
+
+    // check if the device has acknowledged the READ / WRITE mode
+    uint8_t twst = TW_STATUS & 0xF8;
+    if ((twst != TW_MT_SLA_ACK) && (twst != TW_MR_SLA_ACK)) {
+        return 1;
+    }
+
+    return 0;
+}
+
+void i2c_stop(void) {
+    TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO);
+}
+
+uint8_t i2c_write(uint8_t data) {
+    TWDR = data;
+
+    // transmit data and wait
+    TWCR = (1<<TWINT) | (1<<TWEN);
+    while (!(TWCR & (1<<TWINT)));
+
+    if ((TWSR & 0xF8) != TW_MT_DATA_ACK) {
+        return 1;
+    }
+
+    return 0;
+}
+
+uint8_t i2c_send(uint8_t address, uint8_t *data, uint16_t length) {
+    if (i2c_start(address)) {
+        return 1;
+    }
+
+    for (uint16_t i = 0; i < length; i++) {
+        if (i2c_write(data[i])) {
+            return 1;
+        }
+    }
+
+    i2c_stop();
+
+    return 0;
+}