Rabbit RabbitCore RCM4000, Руководство пользователя

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User’s Manual 99
B.4.1 Adding Other Components
There are pads for 28-pin TSSOP devices, 16-pin SOIC devices, and 6-pin SOT devices
that can be used for surface-mount prototyping with these devices. There are also pads that
can be used for SMT resistors and capacitors in an 0805 SMT package. Each component
has every one of its pin pads connected to a hole in which a 30 AWG wire can be soldered
(standard wire wrap wire can be soldered in for point-to-point wiring on the Prototyping
Board). Because the traces are very thin, carefully determine which set of holes is con-
nected to which surface-mount pad.
B.4.2 Measuring Current Draw
The Prototyping Board has a current-measurement feature available at header locations
JP1 and JP2 for the +5 V and +3.3 V supplies respectively. To measure current, you will
have to cut the trace on the bottom side of the Prototyping Board corresponding to the
power supply or power supplies whose current draw you will be measuring. Header loca-
tions JP1 and JP2 are shown in Figure B-5. Then install a 1 × 2 header strip from the
Development Kit on the top side of the Prototyping Board at the header location(s) whose
trace(s) you cut. The header strip(s) will allow you to use an ammeter across their pins to
measure the current drawn from that supply. Once you are done measuring the current,
place a jumper across the header pins to resume normal operation.
Figure B-5. Prototyping Board Current-Measurement Option
NOTE: Once you have cut the trace below header location JP1 or JP2, you must either be
using the ammeter or have a jumper in place in order for power to be delivered to the
Prototyping Board.
A
0
Cut traces
Bottom Side
JP1
JP2
JP1 (+5 V)
or
JP2 (+3.3 V)
CURRENT
MEASUREMENT
D1
R1
PWR
DS1
GND
J1
U1
C1
GND
C2
JP1
C3
D2
JP2
L1C6
C5
JP1
JP2