From 00dfa73e4c642c296bbdbb92ab8202e2e1604ce7 Mon Sep 17 00:00:00 2001 From: WarmCat Date: Sat, 24 Mar 2018 17:03:24 +0000 Subject: Added basic support for JJ50 (preonic-like based on atmega32A) (#2546) * Added support for JJ50 from KPRepublic, no rgb or backlight control yet. Added as a layout of ymd96 at the moment (same microprocessor). Basic keymap with three layers to get started. * Added support for JJ50 --- keyboards/jj50/i2c.c | 104 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 104 insertions(+) create mode 100644 keyboards/jj50/i2c.c (limited to 'keyboards/jj50/i2c.c') diff --git a/keyboards/jj50/i2c.c b/keyboards/jj50/i2c.c new file mode 100644 index 000000000..c27f3e3d1 --- /dev/null +++ b/keyboards/jj50/i2c.c @@ -0,0 +1,104 @@ +/* +Copyright 2016 Luiz Ribeiro + +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 . +*/ + +#include +#include + +#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<