NXP Semiconductors LPC CM0 Series, Руководство пользователя, Страница: 6 / 28

• Bandgap - connect a custom reference (for example 1.65 V) to PIO0_19 (conn. J6-3). The expected value of the custom
bandgap can be set in the
safety_config.h
file (
#define ADC_BANDGAP_LEVEL 1.65
).
An example of the corresponding connection is shown in Figure 2 .
Figure 2. Hardware connection of LPCXpresso845MAX
In Figure 2 , the external debbugger is used. Due to this, jumper JP1 is shorted. The test voltage of 1.65 V is provided by a resistor
voltage divider from the VCC (3.3 V).
2.3 LPCXpresso51U68
Debugger:
To use the on-board debugger and power the board via USB, make sure that jumper JP2 is set to "Loc". Then connect the USB
to connector J6.
The default debugger in the example project is set to CMSIS-DAP.
If downloading to the device does not work, press and hold the SW3 button during the download.
NOTE
FreeMASTER
FreeMASTER communication is used via an on-board debugger with a speed of 9600 bd.
See the
LPCXpresso51U68 development board User Manual
(document UM11121 ) for more details.
The ADC module on the LPCXpresso51U68 does not allow the VrefH, VrefL, and Bandgap to connect internally to the ADC input.
Connect these signals (for the Analog I/O test) as follows:
• VrefH - connect VCC to PIO_0_30 (J8-2).
LPCXpresso51U68
LPC CM0 Safety Example , Rev. 3, 07/2021
NXP Semiconductors 6