User's Manual

On-Ramp Wireless, Inc. 10 014-0033-00 Rev. H
3 Electrical Interface
This chapter describes the electrical interface of the microNode and how the Host processor
controls the microNode.
Table 5. microNode Pin Descriptions
Pin # Pin Name Signal
Direction
Relative to
microNode
Signal
Type
Comment
1, 2, 3, 4, 7, 10 Ground Power Power Ground return. Should be low RF
impedance to a solid ground plane
of the Host
11,14, 17, 20, 21,
26, 30, 31, 34, 35,
37, 38, 40
Ground Power Power
5, 6 VBATT Power Power Input power to the microNode. It is
recommended that the Host
integrator allow for decoupling of
the microNode by placing space
for up to a 100 µF (47 µF nominal)
ceramic capacitor.
Bypass with an
additional 0.1 µF capacitor. This
may or may not be required,
depending on the Host's power
supply and its impedance.
8 SRQ Output CMOS_O Slave Request
9 SRDY Output CMOS_O Slave Ready
12 SCLK Input CMOS_I SPI Clock
13 MISO Output CMOS_O SPI Master Input Slave Output
15 CS Input CMOS_I SPI Chip Select
16 MOSI Input CMOS_I SPI Master Output Slave Input
18 MRQ Input CMOS_I Master Request
19 3V3 Output CMOS_O 3.3V Switcher output from the
Node
22 RESET_N Input OC_1 RESET input
23 USTATUS I/O CMOS_O,
CMOS_I
USTATUS. To be used by the
microNode as a GPIO. Undefined
at this time. Float for now.
24 POWER_ON Input CMOS_A This is used to turn ON/OFF the
Internal Power supplies of the
microNode.
25 ANT_SEL Output CMOS_O This is used by the microNode to
control its antennas for diversity.
27 UART_SIN Input CMOS_I UART Serial input. Not supported
at this time.