3.5.1 Operating at Other Voltages
The WLR089 Xplained Pro Evaluation board operates at 3.3V by default, but it is also possible to run the board at lower voltages from an external supply. The EDBG is designed to run from a 3.3V supply and will not work on other voltages; therefore, all connections from the EDBG and from the on-board 3.3V regulator to the WLR089U0 module must be removed.
To completely disconnect the EDBG and the on-board power supply from the WLR089U0 module, perform the following steps:
- Remove the two jumpers from the on-board 3-pin current measurement headers (J101 and J102) and connect the two center pins (pin 2) together with a wire or an ammeter as shown in Figure 3-3.
- Remove all the EDGB disconnect resistors (refer to Table 3-15).
- Power ON the WLR089 Xplained Pro Evaluation board via pin 4 (3V3) and pin 2 (GND) of the Power Header J100.
- Program the WLR089U0 module using an industry standard 2x5-50 mil cortex debug connector and an external programmer such as Atmel ICE.
Info: Operating the WLR089U0 module at voltages
other than 3.3V requires physical modifications on the kit using a soldering iron
and an external debugger for programming the WLR089U0 module. The on-board current measurement only works at 3.3V. The
on-board LED is selected for 3.3V operation; the LED brightness at 1.8V operation is
dull. To increase the emitted light level, the value of the series resistor can be
lowered. EDBG functionality can be restored by re-soldering the removed
components.
CAUTION: The voltage supplied
through the power header is applied directly to the WLR089U0 module and the extension headers. Applying a voltage greater than 3.5V
may damage the board permanently.
