Bluegiga DKBLE, User Manual

Page: 9 / 21

Bluegiga Technologies Oy
Page 9 of 20
1.2.1 Why the External Flash Chip Doesn
’t Work With BLE121LR Carrier?
The external flash chip is powered with one of the IO
’s of the module. In BLE121LR Carrier the Flash supply is
connected to an IO with 4 mA current driving capability where as in BLE112 and BLE113 Carrier it is
connected to an IO with 20 mA current driving capability. Thus BLE121LR carrier is not able to power the flash
and using the flash with BLE121LR carrier is not possible in DKBLE.
1.2.2 Minimizing the Current Consumption
In all Carriers pin P1_4 is externally pulled down by the pull-down resistor in DKBLE. The purpose of this
resistor is to avoid leakage when using the display. Note that any PIO
’s configured as peripherals do not have
internal pull-down or pull-up capability and thus, when left floating, they will require external pull-down resistor.
For this reason port P1 can
’t be configured to have internal pull-ups (the default setting
of the module) but the port P1 must be pulled low in the HW configuration file.
In BLE121LR carrier also pin P0_7 is externally pulled down by the pull-down resistor in DKBLE.
For these reasons both ports P1 and P2 must be pulled low in the HW configuration file.
The PIO used for the display RS (Register Select) signal has an external pull-down resistor in DKBLE (Note
that P1_0 and P1_1 require external pull-up or pull-down when configured as input).
For these reasons the PIO used for the RS signal must be driven low when the not
writing to the display.
1.3 Sensors, display and USB to UART converter
Device Manufacturer Manufacturer Part Number
USB to UART Converter Prolific PL2303HX rev.D
Display Newhaven Display Intl NHD-C0216CZ-FSW-FBW-3V3
Altimeter Freescale MPL3115A2
Accelerometer Analog Devices ADXL350BCEZ-RL
External Flash Winbond W25X20CLSNIG
Table 2: Sensors, display, external flash and USB to UART converter in DKBLE