93 lines
2.4 KiB
C
93 lines
2.4 KiB
C
/*
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ChibiOS - Copyright (C) 2006..2015 Giovanni Di Sirio
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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/**
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* This is device realize "read through write" paradigm. This is not
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* standard, but most of I2C devices use this paradigm.
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* You must write to device reading address, send restart to bus,
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* and then begin reading process.
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*/
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#include <stdlib.h>
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#include "ch.h"
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#include "hal.h"
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#include "lis3.h"
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#define addr 0b0011101
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/* autoincrement bit position. This bit needs to perform reading of
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* multiple bytes at one request */
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#define AUTO_INCREMENT_BIT (1<<7)
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/* slave specific addresses */
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#define ACCEL_STATUS_REG 0x27
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#define ACCEL_CTRL_REG1 0x20
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#define ACCEL_OUT_DATA 0x28
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/* buffers */
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static uint8_t accel_rx_data[8];
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static uint8_t accel_tx_data[8];
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/*
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*
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*/
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void lis3Start(void){
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msg_t status = MSG_OK;
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systime_t tmo = MS2ST(4);
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/* configure accelerometer */
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accel_tx_data[0] = ACCEL_CTRL_REG1 | AUTO_INCREMENT_BIT;
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accel_tx_data[1] = 0b11100111;
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accel_tx_data[2] = 0b01000001;
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accel_tx_data[3] = 0b00000000;
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/* sending */
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i2cAcquireBus(&I2CD1);
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status = i2cMasterTransmitTimeout(&I2CD1, addr,
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accel_tx_data, 4, accel_rx_data, 0, tmo);
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i2cReleaseBus(&I2CD1);
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osalDbgCheck(MSG_OK == status);
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}
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/*
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*
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*/
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#include <math.h>
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void lis3GetAcc(float *result) {
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msg_t status = MSG_OK;
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systime_t tmo = MS2ST(4);
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size_t i = 0;
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int16_t tmp;
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accel_tx_data[0] = ACCEL_OUT_DATA | AUTO_INCREMENT_BIT;
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i2cAcquireBus(&I2CD1);
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status = i2cMasterTransmitTimeout(&I2CD1, addr,
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accel_tx_data, 1, accel_rx_data, 6, tmo);
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i2cReleaseBus(&I2CD1);
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osalDbgCheck(MSG_OK == status);
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for (i=0; i<3; i++){
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tmp = accel_rx_data[i*2] + (accel_rx_data[i*2+1] << 8);
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result[i] = tmp;
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result[i] /= 16384; /* convert raw value to G */
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}
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}
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