Jaws - DSN Powerdown Feature
TODO: some description, use cases etc.
Terminal Command
dsn get|set btpwdown, for a detailed description have a look at JAWS - Terminal Commands
Modifications in BTnut
- disable buskeeper for external RAM
- set AS0 = 1 to remain Timer0/RTC in
SLEEP_MODE_PWR_SAVEmode - disable ADC
- unprogram BODEN, OCDEN and JTAGEN fuse
- disable Watchdog timer
- set PALE to tristate
code changes:
cbi(XMCRB,XMBK)- undef
NUT_CPU_FREQ, default in BTnut cbi(ADCSR,ADEN)- hfuse = 0xc0, lfuse = 0xbf, SPI programmer needed
wdt_disable(), if enabledcbi(CC1000_CONFIG_PORT_REG,CC1000_PALE), done in CVS HEAD 2007-04-10
Current Consumption Measurements
BTnode runs Jaws and is supplied directly with 3.3 V. The whole current consumption of this platform is presented, starting from a connected state with Bluetooth.
In GUI mode, there is not much saving potential, because the BTnode have to wait after terminal commands and should wake up from the serial line:
In DSN mode, there is more saving potential, because no terminal commands are expected on the serial line:
With SLEEP_MODE_PWR_SAVE, there is a little more saving. But there is a (hopefully linear) deviation from the timer:
The suggested modifications from above chapter are already included in these measurements. Without the changes an additional current consumption of between 0.25 and 0.35 mA was observed...