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authortmk <nobody@nowhere>2014-09-20 06:12:49 +0900
committertmk <nobody@nowhere>2014-09-20 06:12:49 +0900
commit2015027da325e9f9b602af1f36ceeeebbcd6c78d (patch)
tree65e9f6606bf256ce260475aff1ea4eb0c3ba901b /keyboard
parentd8dd18b4217ce56ee3248e3b09598196e0b6731c (diff)
Add FET swtich for battery ADC
Diffstat (limited to 'keyboard')
-rw-r--r--keyboard/hhkb_rn42/MEMO.txt7
-rw-r--r--keyboard/hhkb_rn42/rn42/battery.c12
2 files changed, 19 insertions, 0 deletions
diff --git a/keyboard/hhkb_rn42/MEMO.txt b/keyboard/hhkb_rn42/MEMO.txt
index 11f64b8c4c..2f61574c30 100644
--- a/keyboard/hhkb_rn42/MEMO.txt
+++ b/keyboard/hhkb_rn42/MEMO.txt
@@ -15,12 +15,19 @@ Power saving:
- deep sleep MCU and BT module(keyboard is not used for long time)
- deep sleep MCU and turn off BT module(keyboard is not used and not connected)
- Battery ADC; switching, high resistance
+ - switching gnd end of divider with PF4
+ - high resistor 100K/1M?
+ capacitor 10nF
+ http://www.eevblog.com/forum/beginners/measuring-battery-voltage-without-consuming-current/
Improving:
- BT LED; connecting, linked, sleeping, deep sleeping
- Battry LED; blink(using timer?)
- move rn42 to protocol directory when it becomes reusable stack
- LUFA sendchar should be buffered and serial_uart.c buffur size is too large(256).
+- ADC resolution
+ AVR120
+ AVR32138
Testing:
- Factroy reset doesn't work; need to **test again** 10K pull-up is too high?
diff --git a/keyboard/hhkb_rn42/rn42/battery.c b/keyboard/hhkb_rn42/rn42/battery.c
index c6988fe336..0320e1baf1 100644
--- a/keyboard/hhkb_rn42/rn42/battery.c
+++ b/keyboard/hhkb_rn42/rn42/battery.c
@@ -21,6 +21,10 @@ void battery_init(void)
ADMUX = (1<<REFS1) | (1<<REFS0);
ADCSRA = (1<<ADPS2) | (1<<ADPS1) | (1<<ADPS0);
ADCSRA |= (1<<ADEN);
+
+ // ADC disable voltate divider(PF4)
+ DDRF |= (1<<4);
+ PORTF &= ~(1<<4);
}
// Indicator for battery
@@ -79,6 +83,10 @@ bool battery_charging(void)
// Returns voltage in mV
uint16_t battery_voltage(void)
{
+ // ADC disable voltate divider(PF4)
+ DDRF |= (1<<4);
+ PORTF |= (1<<4);
+
volatile uint16_t bat;
//ADCSRA |= (1<<ADEN);
@@ -98,6 +106,10 @@ uint16_t battery_voltage(void)
//ADCSRA &= ~(1<<ADEN);
+ // ADC disable voltate divider(PF4)
+ DDRF |= (1<<4);
+ PORTF &= ~(1<<4);
+
return (bat - BATTERY_ADC_OFFSET) * BATTERY_ADC_RESOLUTION;
}