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5.3
3 Volt Mode
– Current Measurement
With 5 volt power removed from the board, place the 1V / 3V switch (located in the center right edge of board) in
the 3 volt mode by sliding the switch downwards. (See Section 3.2.3).
With power still removed from the board, remove the jumper from J31 (located just above the ARM mbed logo).
Attach your desired current measuring equipment across the two lower pins of the connector as shown below. The
center pin, Pin 2 on the connector, is the downstream voltage supply rail to the BT4 SoC. Pin 3 on the bottom of
the J31 header of the board is the 3.3 volt supply coming from the LDO regulator. If a GND reference is needed,
please use Pin 1 (the upper most pin on J31) or ground test point (TP13) just to the right of J31 as shown in the
diagram below.
Figure 5.3
– 3 Volt Test Point
Once the desired current measurement equipment is connected to the Eval board, apply power to the board.
Attach the UART to USB cable J14 as described in Section 6.1.2.
Use of the Radio Control Tool (RCT), Section 6, will control the Evaluation board to set the BT4 IP block into
either continuous Tx, continuous Rx or into standby or sleep modes for current measurements in the desired
modes of operation.
The RCT can also be used to vary the regulator output from 1.6 to 3.6 volts. Under 3 volt operation, the RCT can
also control whether the on-chip 3 volt linear or 3 volt switching power regulator is used. Please see the Radio
Control Tool User’s Guide for more information.
Please also note than when using the RCT, both the USB to USB cable and the USB to UART cable must
be installed between the PC and the Eval board. Note the correct position of the Power Control jumper
(J47) to enable RCT control of the voltage regulator. (See Section 3.3.1)