opensteno_qmk/keyboards/handwired/onekey/blackpill_f401/blackpill_f401.c
Sergey Vlasov 0dee334bce
handwired/onekey/blackpill_f401: Fix I2C pin config mismatch (#10322)
By default the `i2c_master` driver for ChibiOS uses the B6 pin for
`I2C1_SCL` and the B7 pin for `I2C1_SDA`.  However, the ChibiOS board
file used for the F401 Blackpill board (`ST_STM32F401C_DISCOVERY`)
configures B6 as `I2C1_SCL` and B9 as `I2C1_SDA`, and if that
configuration is left unchanged, enabling the `i2c_master` driver
results in having two pins (B7 and B9) configured as `I2C1_SDA` at the
same time, which does not work properly (experimental results show that
the B9 pin still works as `I2C1_SDA` in that case, and the B7 pin does
not work).

Configure the B9 pin as an input with pull-up in `board_init()`, so that
the B7 pin can be configured as `I2C1_SDA` by the I2C driver.
2020-11-12 20:00:35 +11:00

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C

/* Copyright 2020 Sergey Vlasov (sigprof)
*
* 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/>.
*/
#include QMK_KEYBOARD_H
void board_init(void) {
// B9 is configured as I2C1_SDA in the board file; that function must be
// disabled before using B7 as I2C1_SDA.
setPinInputHigh(B9);
}