From 3f809e716dea26d77bf2cd8e70c3d709c3c25169 Mon Sep 17 00:00:00 2001 From: Heikki Hannikainen Date: Tue, 6 Aug 2002 10:50:50 +0000 Subject: Added battery charger code for the recorder and battery voltage statistics keeping for all platforms. git-svn-id: svn://svn.rockbox.org/rockbox/trunk@1546 a1c6a512-1295-4272-9138-f99709370657 --- firmware/powermgmt.c | 177 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 177 insertions(+) create mode 100644 firmware/powermgmt.c (limited to 'firmware/powermgmt.c') diff --git a/firmware/powermgmt.c b/firmware/powermgmt.c new file mode 100644 index 0000000000..940d37ea16 --- /dev/null +++ b/firmware/powermgmt.c @@ -0,0 +1,177 @@ +/*************************************************************************** + * __________ __ ___. + * Open \______ \ ____ ____ | | _\_ |__ _______ ___ + * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / + * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < + * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ + * \/ \/ \/ \/ \/ + * $Id$ + * + * Copyright (C) 2002 by Heikki Hannikainen + * + * All files in this archive are subject to the GNU General Public License. + * See the file COPYING in the source tree root for full license agreement. + * + * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY + * KIND, either express or implied. + * + ****************************************************************************/ +#include "config.h" +#include "sh7034.h" +#include "kernel.h" +#include "thread.h" +#include "system.h" +#include "debug.h" +#include "panic.h" +#include "adc.h" +#include "string.h" +#include "power.h" +#include "powermgmt.h" + +#ifndef SIMULATOR + +static char power_stack[DEFAULT_STACK_SIZE]; +static char power_thread_name[] = "power"; + +unsigned short power_history[POWER_HISTORY_LEN]; +#ifdef HAVE_CHARGE_CTRL +char power_message[POWER_MESSAGE_LEN] = ""; +char charge_restart_level = CHARGE_RESTART_HI; +#endif + +/* + * This power thread maintains a history of battery voltage + * and should, in the future, enable charging when it's needed + * and power is available, and disable it when the battery is full. + * Battery 'fullness' can be determined by the voltage drop, see: + * + * http://www.nimhbattery.com/nimhbattery-faq.htm questions 3 & 4 + * http://www.powerpacks-uk.com/Charging%20NiMh%20Batteries.htm + * http://www.angelfire.com/electronic/hayles/charge1.html (soft start idea) + * http://www.powerstream.com/NiMH.htm (discouraging) + * http://www.panasonic.com/industrial/battery/oem/images/pdf/nimhchar.pdf + * http://www.duracell.com/oem/Pdf/others/nimh_5.pdf (discharging) + * http://www.duracell.com/oem/Pdf/others/nimh_6.pdf (charging) + * + * Charging logic which we're starting with (by Linus, Hes, Bagder): + * + * 1) max 16 hrs charge time (just in negative delta detection fails) + * 2) Stop at negative delta of 5 mins + * 3) Stop at 15 mins of zero-delta or below + * 4) minimum of 15 mins charge time before 2) is applied + * 5) after end of charging, wait for charge go down 80% + * before charging again if in 'no-use overnight charging mode' + * and down to 10% if in 'fixed-location mains-powered usage mode' + */ + +static void power_thread(void) +{ + int i; + int avg; +#ifdef HAVE_CHARGE_CTRL + int delta; + int charged_time = 0; +#endif + + while (1) + { + DEBUGF("power_thread woke up\n"); + /* make POWER_AVG measurements and calculate an average of that to + * reduce the effect of backlights/disk spinning/other variation + */ + avg = 0; + for (i = 0; i < POWER_AVG; i++) { + avg += adc_read(ADC_UNREG_POWER); + sleep(15); + } + avg = avg / POWER_AVG; + + /* rotate the power history */ + for (i = 0; i < POWER_HISTORY_LEN-1; i++) + power_history[i] = power_history[i+1]; + + /* insert new value in the end, in decivolts 8-) */ + power_history[POWER_HISTORY_LEN-1] = (avg * BATTERY_SCALE_FACTOR) / 10000; + +#ifdef HAVE_CHARGE_CTRL + if (charger_inserted()) { + if (charger_enabled) { + /* charger inserted and enabled */ + charged_time++; + if (charged_time > CHARGE_MAX_TIME) { + DEBUGF("power: charged_time > CHARGE_MAX_TIME, enough!\n"); + /* have charged too long and deltaV detection did not work! */ + charger_enable(false); + snprintf(power_message, POWER_MESSAGE_LEN, "Chg tmout %d min", CHARGE_MAX_TIME); + /* Perhaps we should disable charging for several + hours from this point, just to be sure. */ + } else { + if (charged_time > CHARGE_MIN_TIME) { + /* have charged continuously over the minimum charging time, + * so we monitor for deltaV going negative. Multiply things + * by 100 to get more accuracy without floating point arithmetic. + * power_history[] contains decivolts. + */ + delta = 0; + for (i = 0; i < CHARGE_END_NEGD; i++) + delta += power_history[POWER_HISTORY_LEN-1-i]*100 - power_history[POWER_HISTORY_LEN-1-i-1]*100; + delta = delta / CHARGE_END_NEGD; + + if (delta < -50) { /* delta < -0.3 V */ + DEBUGF("power: short-term negative delta, enough!\n"); + charger_enable(false); + snprintf(power_message, POWER_MESSAGE_LEN, "end negd %d %dmin", delta, charged_time); + } else { + /* if we didn't disable the charger in the previous test, check for low positive delta */ + delta = 0; + for (i = 0; i < CHARGE_END_ZEROD; i++) + delta += power_history[POWER_HISTORY_LEN-1-i]*100 - power_history[POWER_HISTORY_LEN-1-i-1]*100; + delta = delta / CHARGE_END_ZEROD; + + if (delta <= 5) { /* delta of <= 0.005 V */ + DEBUGF("power: long-term small positive delta, enough!\n"); + charger_enable(false); + snprintf(power_message, POWER_MESSAGE_LEN, "end lowd %d %dmin", delta, charged_time); + } + } + } + } + } else { + /* charged inserted but not enabled */ + /* if battery is not full, enable charging */ + if (battery_level() < charge_restart_level) { + DEBUGF("power: charger inserted and battery not full, enabling\n"); + charger_enable(true); + charged_time = 0; + snprintf(power_message, POWER_MESSAGE_LEN, "Chg started at %d%%", battery_level()); + } + } + } else { + /* charger not inserted */ + if (charger_enabled) { + /* charger not inserted but was enabled */ + DEBUGF("power: charger disconnected, disabling\n"); + charger_enable(false); + snprintf(power_message, POWER_MESSAGE_LEN, "Charger disc"); + } + /* charger not inserted and disabled, so we're discharging */ + } +#endif /* HAVE_CHARGE_CTRL*/ + + /* sleep for roughly a minute */ + sleep(HZ*(60-POWER_AVG*15)); + } +} + +void power_init(void) +{ + /* init history to 0 */ + memset(power_history, 0x00, sizeof(power_history)); + +#ifdef HAVE_CHARGE_CTRL + snprintf(power_message, POWER_MESSAGE_LEN, "Powermgmt started"); +#endif + create_thread(power_thread, power_stack, sizeof(power_stack), power_thread_name); +} + +#endif -- cgit v1.2.3