1
0
mirror of https://github.com/sjlongland/cluster-powerctl.git synced 2025-09-13 12:03:14 +10:00

Initial check-in

This commit is contained in:
Stuart Longland 2016-09-03 17:31:15 +10:00
commit 882541392f
Signed by: stuartl
GPG Key ID: 4DFA191410BDE3B7
9 changed files with 1262 additions and 0 deletions

5
.gitignore vendored Normal file
View File

@ -0,0 +1,5 @@
.*.swp
*.swp
*.o
*.elf
*.hex

340
COPYING Normal file
View File

@ -0,0 +1,340 @@
GNU GENERAL PUBLIC LICENSE
Version 2, June 1991
Copyright (C) 1989, 1991 Free Software Foundation, Inc.
51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
Everyone is permitted to copy and distribute verbatim copies
of this license document, but changing it is not allowed.
Preamble
The licenses for most software are designed to take away your
freedom to share and change it. By contrast, the GNU General Public
License is intended to guarantee your freedom to share and change free
software--to make sure the software is free for all its users. This
General Public License applies to most of the Free Software
Foundation's software and to any other program whose authors commit to
using it. (Some other Free Software Foundation software is covered by
the GNU Library General Public License instead.) You can apply it to
your programs, too.
When we speak of free software, we are referring to freedom, not
price. Our General Public Licenses are designed to make sure that you
have the freedom to distribute copies of free software (and charge for
this service if you wish), that you receive source code or can get it
if you want it, that you can change the software or use pieces of it
in new free programs; and that you know you can do these things.
To protect your rights, we need to make restrictions that forbid
anyone to deny you these rights or to ask you to surrender the rights.
These restrictions translate to certain responsibilities for you if you
distribute copies of the software, or if you modify it.
For example, if you distribute copies of such a program, whether
gratis or for a fee, you must give the recipients all the rights that
you have. You must make sure that they, too, receive or can get the
source code. And you must show them these terms so they know their
rights.
We protect your rights with two steps: (1) copyright the software, and
(2) offer you this license which gives you legal permission to copy,
distribute and/or modify the software.
Also, for each author's protection and ours, we want to make certain
that everyone understands that there is no warranty for this free
software. If the software is modified by someone else and passed on, we
want its recipients to know that what they have is not the original, so
that any problems introduced by others will not reflect on the original
authors' reputations.
Finally, any free program is threatened constantly by software
patents. We wish to avoid the danger that redistributors of a free
program will individually obtain patent licenses, in effect making the
program proprietary. To prevent this, we have made it clear that any
patent must be licensed for everyone's free use or not licensed at all.
The precise terms and conditions for copying, distribution and
modification follow.
GNU GENERAL PUBLIC LICENSE
TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
0. This License applies to any program or other work which contains
a notice placed by the copyright holder saying it may be distributed
under the terms of this General Public License. The "Program", below,
refers to any such program or work, and a "work based on the Program"
means either the Program or any derivative work under copyright law:
that is to say, a work containing the Program or a portion of it,
either verbatim or with modifications and/or translated into another
language. (Hereinafter, translation is included without limitation in
the term "modification".) Each licensee is addressed as "you".
Activities other than copying, distribution and modification are not
covered by this License; they are outside its scope. The act of
running the Program is not restricted, and the output from the Program
is covered only if its contents constitute a work based on the
Program (independent of having been made by running the Program).
Whether that is true depends on what the Program does.
1. You may copy and distribute verbatim copies of the Program's
source code as you receive it, in any medium, provided that you
conspicuously and appropriately publish on each copy an appropriate
copyright notice and disclaimer of warranty; keep intact all the
notices that refer to this License and to the absence of any warranty;
and give any other recipients of the Program a copy of this License
along with the Program.
You may charge a fee for the physical act of transferring a copy, and
you may at your option offer warranty protection in exchange for a fee.
2. You may modify your copy or copies of the Program or any portion
of it, thus forming a work based on the Program, and copy and
distribute such modifications or work under the terms of Section 1
above, provided that you also meet all of these conditions:
a) You must cause the modified files to carry prominent notices
stating that you changed the files and the date of any change.
b) You must cause any work that you distribute or publish, that in
whole or in part contains or is derived from the Program or any
part thereof, to be licensed as a whole at no charge to all third
parties under the terms of this License.
c) If the modified program normally reads commands interactively
when run, you must cause it, when started running for such
interactive use in the most ordinary way, to print or display an
announcement including an appropriate copyright notice and a
notice that there is no warranty (or else, saying that you provide
a warranty) and that users may redistribute the program under
these conditions, and telling the user how to view a copy of this
License. (Exception: if the Program itself is interactive but
does not normally print such an announcement, your work based on
the Program is not required to print an announcement.)
These requirements apply to the modified work as a whole. If
identifiable sections of that work are not derived from the Program,
and can be reasonably considered independent and separate works in
themselves, then this License, and its terms, do not apply to those
sections when you distribute them as separate works. But when you
distribute the same sections as part of a whole which is a work based
on the Program, the distribution of the whole must be on the terms of
this License, whose permissions for other licensees extend to the
entire whole, and thus to each and every part regardless of who wrote it.
Thus, it is not the intent of this section to claim rights or contest
your rights to work written entirely by you; rather, the intent is to
exercise the right to control the distribution of derivative or
collective works based on the Program.
In addition, mere aggregation of another work not based on the Program
with the Program (or with a work based on the Program) on a volume of
a storage or distribution medium does not bring the other work under
the scope of this License.
3. You may copy and distribute the Program (or a work based on it,
under Section 2) in object code or executable form under the terms of
Sections 1 and 2 above provided that you also do one of the following:
a) Accompany it with the complete corresponding machine-readable
source code, which must be distributed under the terms of Sections
1 and 2 above on a medium customarily used for software interchange; or,
b) Accompany it with a written offer, valid for at least three
years, to give any third party, for a charge no more than your
cost of physically performing source distribution, a complete
machine-readable copy of the corresponding source code, to be
distributed under the terms of Sections 1 and 2 above on a medium
customarily used for software interchange; or,
c) Accompany it with the information you received as to the offer
to distribute corresponding source code. (This alternative is
allowed only for noncommercial distribution and only if you
received the program in object code or executable form with such
an offer, in accord with Subsection b above.)
The source code for a work means the preferred form of the work for
making modifications to it. For an executable work, complete source
code means all the source code for all modules it contains, plus any
associated interface definition files, plus the scripts used to
control compilation and installation of the executable. However, as a
special exception, the source code distributed need not include
anything that is normally distributed (in either source or binary
form) with the major components (compiler, kernel, and so on) of the
operating system on which the executable runs, unless that component
itself accompanies the executable.
If distribution of executable or object code is made by offering
access to copy from a designated place, then offering equivalent
access to copy the source code from the same place counts as
distribution of the source code, even though third parties are not
compelled to copy the source along with the object code.
4. You may not copy, modify, sublicense, or distribute the Program
except as expressly provided under this License. Any attempt
otherwise to copy, modify, sublicense or distribute the Program is
void, and will automatically terminate your rights under this License.
However, parties who have received copies, or rights, from you under
this License will not have their licenses terminated so long as such
parties remain in full compliance.
5. You are not required to accept this License, since you have not
signed it. However, nothing else grants you permission to modify or
distribute the Program or its derivative works. These actions are
prohibited by law if you do not accept this License. Therefore, by
modifying or distributing the Program (or any work based on the
Program), you indicate your acceptance of this License to do so, and
all its terms and conditions for copying, distributing or modifying
the Program or works based on it.
6. Each time you redistribute the Program (or any work based on the
Program), the recipient automatically receives a license from the
original licensor to copy, distribute or modify the Program subject to
these terms and conditions. You may not impose any further
restrictions on the recipients' exercise of the rights granted herein.
You are not responsible for enforcing compliance by third parties to
this License.
7. If, as a consequence of a court judgment or allegation of patent
infringement or for any other reason (not limited to patent issues),
conditions are imposed on you (whether by court order, agreement or
otherwise) that contradict the conditions of this License, they do not
excuse you from the conditions of this License. If you cannot
distribute so as to satisfy simultaneously your obligations under this
License and any other pertinent obligations, then as a consequence you
may not distribute the Program at all. For example, if a patent
license would not permit royalty-free redistribution of the Program by
all those who receive copies directly or indirectly through you, then
the only way you could satisfy both it and this License would be to
refrain entirely from distribution of the Program.
If any portion of this section is held invalid or unenforceable under
any particular circumstance, the balance of the section is intended to
apply and the section as a whole is intended to apply in other
circumstances.
It is not the purpose of this section to induce you to infringe any
patents or other property right claims or to contest validity of any
such claims; this section has the sole purpose of protecting the
integrity of the free software distribution system, which is
implemented by public license practices. Many people have made
generous contributions to the wide range of software distributed
through that system in reliance on consistent application of that
system; it is up to the author/donor to decide if he or she is willing
to distribute software through any other system and a licensee cannot
impose that choice.
This section is intended to make thoroughly clear what is believed to
be a consequence of the rest of this License.
8. If the distribution and/or use of the Program is restricted in
certain countries either by patents or by copyrighted interfaces, the
original copyright holder who places the Program under this License
may add an explicit geographical distribution limitation excluding
those countries, so that distribution is permitted only in or among
countries not thus excluded. In such case, this License incorporates
the limitation as if written in the body of this License.
9. The Free Software Foundation may publish revised and/or new versions
of the General Public License from time to time. Such new versions will
be similar in spirit to the present version, but may differ in detail to
address new problems or concerns.
Each version is given a distinguishing version number. If the Program
specifies a version number of this License which applies to it and "any
later version", you have the option of following the terms and conditions
either of that version or of any later version published by the Free
Software Foundation. If the Program does not specify a version number of
this License, you may choose any version ever published by the Free Software
Foundation.
10. If you wish to incorporate parts of the Program into other free
programs whose distribution conditions are different, write to the author
to ask for permission. For software which is copyrighted by the Free
Software Foundation, write to the Free Software Foundation; we sometimes
make exceptions for this. Our decision will be guided by the two goals
of preserving the free status of all derivatives of our free software and
of promoting the sharing and reuse of software generally.
NO WARRANTY
11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN
OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS
TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE
PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
REPAIR OR CORRECTION.
12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGES.
END OF TERMS AND CONDITIONS
How to Apply These Terms to Your New Programs
If you develop a new program, and you want it to be of the greatest
possible use to the public, the best way to achieve this is to make it
free software which everyone can redistribute and change under these terms.
To do so, attach the following notices to the program. It is safest
to attach them to the start of each source file to most effectively
convey the exclusion of warranty; and each file should have at least
the "copyright" line and a pointer to where the full notice is found.
<one line to give the program's name and a brief idea of what it does.>
Copyright (C) <year> <name of author>
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, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
Also add information on how to contact you by electronic and paper mail.
If the program is interactive, make it output a short notice like this
when it starts in an interactive mode:
Gnomovision version 69, Copyright (C) year name of author
Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
This is free software, and you are welcome to redistribute it
under certain conditions; type `show c' for details.
The hypothetical commands `show w' and `show c' should show the appropriate
parts of the General Public License. Of course, the commands you use may
be called something other than `show w' and `show c'; they could even be
mouse-clicks or menu items--whatever suits your program.
You should also get your employer (if you work as a programmer) or your
school, if any, to sign a "copyright disclaimer" for the program, if
necessary. Here is a sample; alter the names:
Yoyodyne, Inc., hereby disclaims all copyright interest in the program
`Gnomovision' (which makes passes at compilers) written by James Hacker.
<signature of Ty Coon>, 1 April 1989
Ty Coon, President of Vice
This General Public License does not permit incorporating your program into
proprietary programs. If your program is a subroutine library, you may
consider it more useful to permit linking proprietary applications with the
library. If this is what you want to do, use the GNU Library General
Public License instead of this License.

50
Makefile Normal file
View File

@ -0,0 +1,50 @@
# Solar Powered Personal Cloud Power Controller
# (C) 2016 Stuart Longland
#
# 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, write to the Free Software Foundation, Inc.,
# 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
-include local.mk
CFLAGS = -Os -g -mmcu=attiny24a -Wall -Werror
LDFLAGS = -mmcu=attiny24a -Wall -Werror
CPPFLAGS = -DF_CPU=1000000UL
CROSS_COMPILE ?= avr-
CC = $(CROSS_COMPILE)gcc
OBJCOPY = $(CROSS_COMPILE)objcopy
OBJDUMP = $(CROSS_COMPILE)objdump
SIZE = $(CROSS_COMPILE)size
PROG_ARGS ?=-c stk500v2 -P /dev/ttyACM0
PROG_DEV ?= t24
.PHONY: clean all
all: powerctl.ihex
clean:
-rm *.ihex *.elf *.o
%.ihex: %.elf
$(OBJCOPY) -j .text -j .data -O ihex $^ $@
%.elf:
$(CC) $(LDFLAGS) -o $@ $^
$(SIZE) -d $@
powerctl.elf: powerctl.o uart.o
powerctl.o: board.h
uart.o: uartcfg.h uart.h
%.pgm: %.ihex
avrdude $(PROG_ARGS) -p $(PROG_DEV) -U flash:w:$^:i

111
README.md Normal file
View File

@ -0,0 +1,111 @@
Power controller for solar powered personal cloud
=================================================
This firmware is intended to control the charging of a battery bank that
powers a small computer cluster running a private cloud system. The
idea is to try to keep the battery within a small range of voltages,
charging from solar or mains based chargers as necessary to top the
battery back up.
Circuit description
-------------------
An ATTiny24A microcontroller runs from a 5V rail derived from the
battery. It uses its internal RC oscillator running at 1MHz.
Connected to PB0 and PB1 are the two MOSFETs that turn on the input
sources, one for solar (PB1), the other for a mains charger (PB0).
The source pins of these connect to the battery positive input, so when
the FET is on, power may flow from that source to the battery.
A third MOSFET connects to PB2, this is PWM-controlled to manage some
cooling fans. The internal temperature sensor is used to decide whether
the fans should be on or off, and at what speed.
Connecting to each input, and to the battery, are separate voltage
dividers, comprising of a 1.5kOhm and 100Ohm resistors. These divide
the input voltage by 16, and the divided voltage is fed into the ADC
pins PA0 (mains), PA1 (solar) and PA2 (battery).
LEDs connect to PA7, PA6, PA5, PA4 and PA3 to 0v. ICSP is shared with the
LEDs.
GPIOs
-----
PB0: Mains MOSFET (active HIGH)
PB1: Solar MOSFET (active HIGH)
PB2: Fan MOSFET (active HIGH)
PB3: nRESET
PA7: Temperature Low LED (active HIGH)
PA6: Temperature High LED (active HIGH) + ICSP MOSI
PA5: Battery Voltage High LED (active HIGH) + ICSP MISO
PA4: Warning LED (active high) + ICSP SCK + Debug Tx
PA3: Battery Voltage Good LED (active HIGH)
PA2: Analogue Input: Battery voltage
PA1: Analogue Input: Solar voltage
PA0: Analogue Input: Mains voltage
Firmware description
--------------------
The firmware may be compiled in DEBUG mode by adding -DDEBUG to the
CPPFLAGS. In this mode, PA4 is used instead for a UART Tx pin at 1200
baud, 8 bits, no parity, one stop bit. This is done in software, using
Timer 1 as a baud rate generator.
Timer 1 also does double-duty managing timings for events.
Timer 0 is used in PWM mode to control the fans.
The firmware does some quick initialisation before entering the main
loop. If DEBUG is enabled, "INIT xx" will be displayed, where xx is the
value of the MCUSR register.
Two counters are decremented by the Timer 1 overflow interrupt.
`led_timeout` causes the main loop to update the state of the LEDs when
it hits zero, and `adc_timeout` triggers a new ADC capture run when it
reaches zero.
The three analogue inputs and temperature sensor are scanned when
`adc_timeout` reaches zero, then the state analysed. The battery
voltage is compared to the previous reading to dissern if the battery is
charging, discharging or holding steady.
If this state has not changed, a battery state counter increments,
otherwise it is reset.
The current state of the FETs is checked. Three states are valid:
- Idle state: all FETs off
- Mains charge: MAINS FET turned on
- Solar charge: SOLAR FET turned on
IF statements at this point compare the battery voltage to the
thresholds, and decide whether to switch voltage or not.
LED indications
---------------
The LEDs have the following meanings:
Warning LED (PA4; DEBUG undefined):
- Off: No warning condition
- Flashing: Battery below critical threshold or temperature above
maximum threshold
- On: Not used
When in DEBUG mode, this LED may flicker with serial activity, and will
remain ON when idle.
Temperature LEDs (PA6, PA7):
- PA7 On, PA6 Off: Temperature below minimum threshold
- PA7 Flashing, PA6 Off: Temperature above minimum threshold
- PA7 Off, PA6 Flashing: Temperature above maximum threshold
- Other states: not used
Battery LEDs (PA5, PA3):
- PA3 Flashing, PA5 Off: Battery below low threshold
- PA3 Off, PA5 Flashing: Battery above high threshold
- PA3 On, PA5 Off: Battery is in "good" range (between low and high)
- Other states: not used

37
board.h Normal file
View File

@ -0,0 +1,37 @@
#ifndef _BOARD_H
#define _BOARD_H
/* LEDs */
#define LED_TEMP_LOW (1 << 7)
#define LED_TEMP_HIGH (1 << 6)
#define LED_BATT_HIGH (1 << 5)
#define LED_WARNING (1 << 4)
#define LED_BATT_GOOD (1 << 3)
#define LED_PORT PORTA
#define LED_PORT_DDR_REG DDRA
#define LED_PORT_DDR_VAL ( LED_TEMP_LOW \
| LED_TEMP_HIGH \
| LED_BATT_HIGH \
| LED_WARNING \
| LED_BATT_GOOD )
/* MOSFETs */
#define FET_MAINS (1 << 0)
#define FET_SOLAR (1 << 1)
#define FET_FAN (1 << 2)
#define FET_SRC_MASK (FET_MAINS|FET_SOLAR)
#define FET_PORT PORTB
#define FET_PORT_DDR_REG DDRB
#define FET_PORT_DDR_VAL ( FET_MAINS \
| FET_SOLAR \
| FET_FAN )
/* ADC channels */
#define ADC_CH_MAINS (1 << 0)
#define ADC_CH_SOLAR (1 << 1)
#define ADC_CH_BATT (1 << 2)
#define ADC_CH_EN ( ADC_CH_MAINS \
| ADC_CH_SOLAR \
| ADC_CH_BATT )
#endif

506
powerctl.c Normal file
View File

@ -0,0 +1,506 @@
#include <avr/interrupt.h>
#include <avr/io.h>
#include <stdint.h>
#include <avr/pgmspace.h>
#ifdef DEBUG
/*! If enabled, the warning LED doubles as UART Tx pin */
#include "uart.h"
#endif
#include "board.h"
/*! ADMUX setting for selecting 1.1V reference */
#define ADC_REF_1V1 (2 << REFS0)
/*! ADMUX setting for mains input voltage reading */
#define ADC_MUX_MAINS (ADC_REF_1V1 | 0x00)
/*! ADMUX setting for solar input voltage reading */
#define ADC_MUX_SOLAR (ADC_REF_1V1 | 0x01)
/*! ADMUX setting for battery input voltage reading */
#define ADC_MUX_BATT (ADC_REF_1V1 | 0x02)
/*! ADMUX setting for temperature reading */
#define ADC_MUX_TEMP (ADC_REF_1V1 | 0x22)
/*!
* For state machine, the last state of the ADC MUX so we know whether
* to ignore the sample or not. Datasheet recommends discarding samples
* to let things stabalise when switching sources/references.
*/
static volatile uint8_t last_admux = 0;
/*!
* For state machine, determines what the battery was one sample ago so
* we know if it's charging, discharging, or remaining static. ADC units.
*/
static volatile uint16_t last_adc_batt = 0;
/*!
* Current reading of the battery voltage in ADC units.
*/
static volatile uint16_t adc_batt = 0;
/*!
* Current reading of the solar charger voltage in ADC units.
*/
static volatile uint16_t adc_solar = 0;
/*!
* Current reading of the mains charger voltage in ADC units.
*/
static volatile uint16_t adc_mains = 0;
/*!
* Current reading of the internal temperature sensor in ADC units.
*/
static volatile uint16_t adc_temp = 0;
/*!
* How long before we next take a reading?
*/
static volatile uint16_t adc_timeout = 0;
/*!
* How many Timer1 ticks between ADC readings?
*/
#define ADC_TIMEOUT (1200)
/*!
* State of the battery.
* -1: discharging
* 0: remaining steady
* 1: charging
*/
static volatile int8_t batt_state = 0;
/*!
* The state of the battery at last check.
*/
static volatile int8_t last_batt_state = 0;
/*!
* The number of readings that the battery has maintained this state.
*/
static volatile uint8_t batt_state_counter = 0;
/*!
* How long before we can consider switching sources.
*/
static volatile uint8_t src_timeout = 0;
#define SRC_TIMEOUT (15) /*!< How long to wait before switching */
/*!
* How long before we change LED states?
*/
static volatile uint8_t led_timeout = 0;
#define LED_TIMEOUT (150)
/*
* Temperature ranges and fan PWM settings
*/
#define TEMP_MIN (275 << 6) /*!< ~20°C, approx ADC reading */
#define TEMP_MAX (295 << 6) /*!< ~30°C, approx ADC reading */
#define FAN_PWM_MIN (128) /*!< Minimum PWM value */
#define FAN_PWM_MAX (255) /*!< Maximum PWM value */
/*
* ADC Voltage divider settings
*/
#define VDIV_R1 (1500ULL) /*!< R1 = 1.5kOhm */
#define VDIV_R2 (100ULL) /*!< R2 = 100 Ohm */
/*
* ADC settings
*/
#define ADC_REF (1100ULL) /*!< AREF = 1.1mV */
#define ADC_MAX (65535ULL) /*!< ADLAR = 1 */
/*!
* Macro for computing ADC measurements. This assumes the input to the
* ADC pin is via a voltage divider made up of resistors R1 and R2, with
* the input voltage applied across both resistors and the ADC measuring
* across R2.
*
* @param mv Voltage in millivolts
* @returns Approximate ADC reading
*/
# define ADC_READ(mv) ( \
(ADC_MAX * ((uint64_t)(mv)) * VDIV_R2) \
/ \
(ADC_REF * (VDIV_R1 + VDIV_R2)) \
)
/*!
* "Critical" battery voltage. This is considered a serious condition.
*/
#define VBATT_CRIT ADC_READ(11800)
/*!
* "Low" battery voltage. Indication that we should turn a charger on.
*/
#define VBATT_LOW ADC_READ(12000)
/*!
* "High" battery voltage. Indication we should turn the charger off.
*/
#define VBATT_HIGH ADC_READ(13500)
/* Debug messages */
#ifdef DEBUG
const char STR_INIT[] PROGMEM = {"INIT "};
const char STR_ADC[] PROGMEM = {"ADC "};
const char STR_START[] PROGMEM = {"START "};
const char STR_READ[] PROGMEM = {"READ "};
const char STR_NL[] PROGMEM = {"\r\n"};
#endif
#define SRC_NONE (0) /*!< Turn off all chargers */
#define SRC_SOLAR (1) /*!< Turn on solar charger */
#define SRC_MAINS (2) /*!< Turn on mains charger */
/*!
* Switch between chargers. This is does a "break-before-make" switchover
* of charging sources to switch from mains to solar, solar to mains, or to
* switch from charging to discharging mode. It expressly forbids turning
* both chargers on simultaneously.
*/
void select_src(uint8_t src) {
switch(src) {
case SRC_SOLAR:
FET_PORT &= ~FET_MAINS;
FET_PORT |= FET_SOLAR;
break;
case SRC_MAINS:
FET_PORT &= ~FET_SOLAR;
FET_PORT |= FET_MAINS;
break;
case SRC_NONE:
default:
FET_PORT &= ~FET_SRC_MASK;
break;
}
src_timeout = SRC_TIMEOUT;
}
/*!
* Main entrypoint */
int main(void) {
/* Configure LEDs */
LED_PORT_DDR_REG = LED_PORT_DDR_VAL;
LED_PORT = 0;
/* Configure MOSFETs */
FET_PORT_DDR_REG = FET_PORT_DDR_VAL;
FET_PORT = 0;
/* Turn on ADC and timers */
PRR &= ~((1 << PRTIM0) | (1 << PRTIM1) | (1 << PRADC));
/* Configure Timer0: Fan PWM */
TCCR0A = (1 << COM0A1) | (1 << WGM01) | (1 << WGM00);
TCCR0B = (1 << CS00);
/* Half-speed fan until we know what to do */
OCR0A = 128;
/*
* Configure Timer1: 1.2kHz System tick timer
* / baud rate generator for debug output
*/
TCCR1A = 0;
TCCR1B = (1 << WGM12) | (1 << CS10);
TCCR1C = 0;
OCR1A = F_CPU/1200;
TIMSK1 = (1 << OCIE1A);
/* ADC configuration */
DIDR0 = ADC_CH_EN;
ADMUX = ADC_MUX_TEMP;
ADCSRB = (1 << ADLAR);
ADCSRA = (1 << ADIE)
| (1 << ADPS2)
| (1 << ADPS1)
| (1 << ADPS0);
/* Configure UART */
sei();
#ifdef DEBUG
uart_init();
uart_tx_str(STR_INIT);
uart_tx_hex_byte(MCUSR);
uart_tx_str(STR_NL);
#endif
MCUSR = 0;
while(1) {
if (!led_timeout) {
#ifndef DEBUG
if ((adc_batt < VBATT_CRIT)
|| (adc_temp > TEMP_MAX)) {
/* Warning conditions */
LED_PORT ^= LED_WARNING;
} else {
LED_PORT &= ~LED_WARNING;
}
#endif
if (adc_batt < VBATT_LOW) {
/* Battery is low */
LED_PORT &= ~LED_BATT_HIGH;
LED_PORT ^= LED_BATT_GOOD;
} else if (adc_batt >= VBATT_HIGH) {
/* Battery is above "high" threshold */
LED_PORT ^= LED_BATT_HIGH;
LED_PORT &= ~LED_BATT_GOOD;
} else {
/* Battery is above "low" threshold */
LED_PORT |= LED_BATT_GOOD;
LED_PORT &= ~LED_BATT_HIGH;
}
if (adc_temp < TEMP_MIN) {
LED_PORT |= LED_TEMP_LOW;
LED_PORT &= ~LED_TEMP_HIGH;
} else if (adc_temp < TEMP_MAX) {
LED_PORT ^= LED_TEMP_LOW;
LED_PORT &= ~LED_TEMP_HIGH;
} else {
LED_PORT &= ~LED_TEMP_LOW;
LED_PORT ^= LED_TEMP_HIGH;
}
led_timeout = LED_TIMEOUT;
}
if (!adc_timeout) {
adc_timeout = ADC_TIMEOUT;
ADCSRA |= (1 << ADEN) | (1 << ADSC);
#ifdef DEBUG
uart_tx_str(STR_ADC);
uart_tx_str(STR_READ);
#endif
while(ADCSRA & (1 << ADEN));
#ifdef DEBUG
uart_tx_str(STR_NL);
uart_tx_str(STR_ADC);
uart_tx('T'); uart_tx_hex_word(adc_temp);
uart_tx(' ');
uart_tx('B'); uart_tx_hex_word(adc_batt);
uart_tx(' ');
uart_tx('L'); uart_tx_hex_word(last_adc_batt);
uart_tx(' ');
uart_tx('d');
if (last_adc_batt > adc_batt) {
uart_tx('-');
uart_tx_hex_word(last_adc_batt - adc_batt);
} else {
uart_tx('+');
uart_tx_hex_word(adc_batt - last_adc_batt);
}
uart_tx(' ');
uart_tx('S'); uart_tx_hex_word(adc_solar);
uart_tx(' ');
uart_tx('M'); uart_tx_hex_word(adc_mains);
uart_tx(' ');
uart_tx('F'); uart_tx_hex_byte(FET_PORT);
#endif
/* Battery direction */
#ifdef DEBUG
uart_tx(' ');
uart_tx('b');
#endif
if ((!last_adc_batt) || (adc_batt == last_adc_batt)) {
batt_state = 0; /* Steady? */
#ifdef DEBUG
uart_tx('=');
#endif
} else if (adc_batt > last_adc_batt) {
batt_state = 1;
#ifdef DEBUG
uart_tx('+');
#endif
} else if (adc_batt < last_adc_batt) {
batt_state = -1;
#ifdef DEBUG
uart_tx('-');
#endif
}
if (last_batt_state == batt_state) {
batt_state_counter++;
} else {
batt_state_counter = 0;
last_batt_state = batt_state;
}
/* Battery control */
uint8_t state = FET_PORT & FET_SRC_MASK;
switch (state) {
case 0:
/* Idle state */
#ifdef DEBUG
uart_tx('I');
#endif
if ((adc_batt < VBATT_CRIT)
&& (adc_mains > adc_batt)) {
/* Charger urgently needed. */
#ifdef DEBUG
uart_tx('C');
uart_tx('M');
#endif
select_src(SRC_MAINS);
} else if (adc_batt < VBATT_LOW) {
/* Charger needed. */
#ifdef DEBUG
uart_tx('L');
#endif
if ((adc_solar >= adc_mains)
&& (adc_solar > adc_batt)) {
#ifdef DEBUG
uart_tx('S');
#endif
select_src(SRC_SOLAR);
} else {
#ifdef DEBUG
uart_tx('M');
#endif
select_src(SRC_MAINS);
}
}
break;
case FET_SOLAR:
#ifdef DEBUG
uart_tx('S');
#endif
/* Are we over voltage? */
if (adc_batt >= VBATT_HIGH) {
#ifdef DEBUG
uart_tx('H');
#endif
select_src(SRC_NONE);
} else if ((adc_batt < VBATT_CRIT)
&& (adc_mains > adc_solar)
&& (adc_mains > adc_batt)) {
#ifdef DEBUG
uart_tx('C');
#endif
select_src(SRC_MAINS);
/* Are we still discharging? */
} else if ((!src_timeout)
&& (adc_mains > adc_batt)
&& (batt_state <= 0)
&& (batt_state_counter > 10)) {
#ifdef DEBUG
uart_tx('M');
#endif
select_src(SRC_MAINS);
} else if (src_timeout) {
#ifdef DEBUG
uart_tx('s');
uart_tx_hex_byte(batt_state_counter);
uart_tx('t');
uart_tx_hex_byte(src_timeout);
#endif
src_timeout--;
}
break;
case FET_MAINS:
#ifdef DEBUG
uart_tx('M');
#endif
/* Are we over voltage? */
if (adc_batt >= VBATT_HIGH) {
#ifdef DEBUG
uart_tx('H');
#endif
select_src(SRC_NONE);
/* Are we still critical? */
} else if (adc_batt < VBATT_CRIT) {
#ifdef DEBUG
uart_tx('C');
#endif
if (adc_mains < adc_solar) {
/* Mains no good, try solar */
#ifdef DEBUG
uart_tx('S');
#endif
select_src(SRC_SOLAR);
}
/* Is solar better now? */
} else if ((!src_timeout)
&& (adc_solar > adc_mains)) {
#ifdef DEBUG
uart_tx('S');
#endif
select_src(SRC_SOLAR);
} else if (src_timeout) {
#ifdef DEBUG
uart_tx('t');
uart_tx_hex_byte(src_timeout);
#endif
src_timeout--;
}
break;
default:
/* Should not get here */
#ifdef DEBUG
uart_tx('!');
#endif
select_src(SRC_NONE);
}
/* Fan control */
if (adc_temp > TEMP_MAX) {
/* We're at the maximum temperature, FULL SPEED! */
OCR0A = FAN_PWM_MAX;
} else if (adc_temp > TEMP_MIN) {
/* Scale fan speed linearly with temperature */
OCR0A = (((adc_temp - TEMP_MIN)
* (FAN_PWM_MIN - FAN_PWM_MAX))
/ (TEMP_MAX - TEMP_MIN))
+ FAN_PWM_MIN;
} else {
/* Turn fans off completely. */
OCR0A = 0;
}
#ifdef DEBUG
uart_tx(' ');
uart_tx('f');
uart_tx_hex_byte(OCR0A);
uart_tx_str(STR_NL);
#endif
}
}
return 0;
}
ISR(TIM1_COMPA_vect) {
#ifdef DEBUG
uart_tick();
#endif
if (adc_timeout)
adc_timeout--;
if (led_timeout)
led_timeout--;
}
ISR(ADC_vect) {
uint16_t adc = ADCW;
if (last_admux == ADMUX) {
switch(last_admux) {
case ADC_MUX_TEMP:
adc_temp = adc;
ADMUX = ADC_MUX_BATT;
ADCSRA |= (1 << ADSC);
break;
case ADC_MUX_BATT:
last_adc_batt = adc_batt;
adc_batt = adc;
ADMUX = ADC_MUX_SOLAR;
ADCSRA |= (1 << ADSC);
break;
case ADC_MUX_SOLAR:
adc_solar = adc;
ADMUX = ADC_MUX_MAINS;
ADCSRA |= (1 << ADSC);
break;
case ADC_MUX_MAINS:
adc_mains = adc;
default:
ADMUX = ADC_MUX_TEMP;
ADCSRA &= ~(1 << ADEN);
}
} else {
ADCSRA |= (1 << ADSC);
last_admux = ADMUX;
}
}

116
uart.c Normal file
View File

@ -0,0 +1,116 @@
/*!
* Very simple software UART for AVR microcontrollers
* (C) 2016 Stuart Longland
*
* 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, write to the Free Software Foundation, Inc.,
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "uart.h"
#include "uartcfg.h"
#include <avr/io.h>
#include <util/delay.h>
#include <stdint.h>
#include <avr/pgmspace.h>
#define TX_BIT (1 << UART_TX_BIT)
#define BIT_US (1000000/UART_BAUD) /*!< Bit period in microseconds */
static volatile uint8_t uart_ticks = 0;
/*!
* Configure the UART pins.
*/
void uart_init() {
UART_TX_DDR |= TX_BIT;
UART_TX_PORT |= TX_BIT;
}
static void uart_wait(uint8_t ticks) {
uart_ticks = ticks;
while(uart_ticks);
}
void uart_tick() {
if (uart_ticks)
uart_ticks--;
}
/*!
* Send a raw byte to the UART.
*/
void uart_tx(uint8_t byte) {
uint8_t mask = 1;
/* Start bit */
UART_TX_PORT &= ~TX_BIT; uart_wait(1);
while(mask) {
if (mask & byte)
UART_TX_PORT |= TX_BIT;
else
UART_TX_PORT &= ~TX_BIT;
uart_wait(1);
mask <<= 1;
}
/* Stop bit */
UART_TX_PORT |= TX_BIT; uart_wait(1);
}
/*!
* Send a text string (in pgmspace) to the UART.
* String shall be null-terminated!
*/
void uart_tx_str(const char* str) {
char c = pgm_read_byte(str);
while (c) {
str++;
uart_tx(c);
c = pgm_read_byte(str);
}
}
/*!
* Send a 4-bit nybble to the UART.
*/
void uart_tx_hex(uint8_t nybble) {
if (nybble >= 10)
uart_tx(nybble - 10 + 'a');
else
uart_tx(nybble + '0');
}
/*!
* Send a 8-bit byte to the UART.
*/
void uart_tx_hex_byte(uint8_t byte) {
uart_tx_hex(byte >> 4);
uart_tx_hex(byte & 0x0f);
}
/*!
* Send a 16-bit word to the UART.
*/
void uart_tx_hex_word(uint16_t word) {
uart_tx_hex_byte(word >> 8);
uart_tx_hex_byte(word & 0xff);
}
/*!
* Send a 32-bit long word to the UART.
*/
void uart_tx_hex_lword(uint32_t lword) {
uart_tx_hex_word(lword >> 16);
uart_tx_hex_word(lword & 0xffff);
}

60
uart.h Normal file
View File

@ -0,0 +1,60 @@
#ifndef _UART_H
#define _UART_H
/*!
* Very simple software UART for AVR microcontrollers
* (C) 2016 Stuart Longland
*
* 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, write to the Free Software Foundation, Inc.,
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <stdint.h>
/*!
* Configure the UART pins.
*/
void uart_init();
/*!
* UART tick timer
*/
void uart_tick();
/*!
* Send a raw byte to the UART.
*/
void uart_tx(uint8_t byte);
/*!
* Send a text string (in pgmspace) to the UART.
* String shall be null-terminated!
*/
void uart_tx_str(const char* str);
/*!
* Send a 8-bit byte to the UART.
*/
void uart_tx_hex_byte(uint8_t byte);
/*!
* Send a 16-bit word to the UART.
*/
void uart_tx_hex_word(uint16_t word);
/*!
* Send a 32-bit long word to the UART.
*/
void uart_tx_hex_lword(uint32_t lword);
#endif

37
uartcfg.h Normal file
View File

@ -0,0 +1,37 @@
#ifndef _UARTCFG_H
#define _UARTCFG_H
/*!
* Very simple software UART for AVR microcontrollers
* (C) 2016 Stuart Longland
*
* 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, write to the Free Software Foundation, Inc.,
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*/
/* The following defines the configuration for the UART driver. */
/*!
* UART BAUD rate. This is the speed that we transmit at. For the 1MHz
* RC clock, 4800 is the maximum speed (out of the "standard" ones) that
* will work. If you're running at 8MHz or with an external crystal, you
* may go higher.
*/
#define UART_BAUD (300)
/* Port settings */
#define UART_TX_PORT PORTA /*!< GPIO port register for Tx */
#define UART_TX_DDR DDRA /*!< GPIO direction register for Tx */
#define UART_TX_BIT 4 /*!< GPIO pin for Tx */
#endif