Introduction
============
This is a temperature logging application for VESNA. It periodically logs
temperature readings from the internal temperature sensor in the STM32F103
microcontroller to SRAM. Logged data is dumped on the serial port at the
push of the button.
It puts the microcontroller to stop mode between readouts and shuts down
most of hardware on board VESNA so it is possible to run this application
on battery power. The current draw is in the order of a few milliamperes.
Compilation
===========
To compile and upload firmware to a VESNA using OpenOCD and Olimex
ARM-USB-OCD:
$ make temperature-log.u
You can adjust the logging interval via a constant in the temperature-log.c
source file.
Usage
=====
Logging starts as soon as VESNA boots.
Note that when running on battery power VESNA will start only after the
button has been pressed.
Temperature will be logged until memory is exhausted (24000 measurements by
default).
To write the log to a file, connect VESNA to a serial port and run:
$ stty -F /dev/ttyUSB0 115200
$ cat /dev/ttyUSB0 > temperature-log.csv
Or use your favorite serial terminal emulator.
Press the button on VESNA to transfer the data. Be careful to only press
the button for a short time. A press longer than 1 second will reset VESNA
and all the measurements will be lost.
Note that to obtain the temperature in degrees Celsius from the logged
samples you must use the following function:
n * 3.3 1
Tc = 25 C + ( V25 - -------- ) * -------
2^12 - 1 kslope
Where:
n - temperature sensor samples
V25 - sensor voltage at 25 C (typ. 1.43 V)
kslope - sensor slope (typ. 4.3 mV/C)
Refer to the STM32F103 datasheet and reference manual for details.
License
=======
Copyright (C) 2012 SensorLab, Jozef Stefan Institute
http://sensorlab.ijs.si
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/>.
Author: Tomaz Solc, <tomaz.solc@ijs.si>