8seg/driver_fw/mcp9801.c

42 lines
1.5 KiB
C

/* 8seg LED display driver firmware
* Copyright (C) 2018 Sebastian Götte <code@jaseg.net>
*
* 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 3 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 "global.h"
#include "i2c.h"
#include "mcp9801.h"
void mcp9801_init()
{
uint8_t config = MCP9801_ONESHOT_OFF | MCP9801_RES_12BIT | MCP9801_FAULT_QUEUE_1 | MCP9801_ALERT_LOW | \
MCP9801_MODE_COMP | MCP9801_SHUTDOWN_OFF;
uint8_t buf[2] = { MCP9801_REG_CONFIG, config };
i2c_transmit(MCP9801_I2C_PERIPH, buf, sizeof(buf), MCP9801_I2C_ADDR, I2C_GENSTOP_YES);
/* Address device here */
uint8_t buf2[1] = { MCP9801_REG_TEMP };
i2c_transmit(MCP9801_I2C_PERIPH, buf2, sizeof(buf2), MCP9801_I2C_ADDR, I2C_GENSTOP_NO);
}
int32_t mcp9801_read_mdegC()
{
uint8_t rx[2];
i2c_receive(MCP9801_I2C_PERIPH, rx, sizeof(rx), MCP9801_I2C_ADDR);
/* Fixup endianness, sign-extend */
int32_t temp = (int16_t)((rx[0]<<8) | rx[1]);
return (temp * 1000) /256;
}