The PROstart is footprint and pin compatible
with the Arduino PRO.
BASIC or C programs can be downloaded using the installed test connector
using the USB dongle contained in Coridium's evaluation kit or using the SparkFun USB Basic Breakout board or FTDI cable from Digikey. More details on these
connections here
.
Digital IO connections
Port pins can be controlled
with the
P0..P4 keywords. Port 0 pins can be
accessed with the original
IN, OUT... keywords
. More details on the GPIOs
can be found in the NXP User Manual.
The LPC1114 supports a number of dedicated functions. Those
include 4 timers, 2 SPIs, and I2C.
In addition most can be configured with
pullups and default to pullups following reset.
Details can be found in NXP's User
manual.
Analog connections
6 A/D converters are readily available, Analog 0-5.
1 10 bit DAC is available
shared with AD(3) available on the SuperPRO (not on PROplus)
On reset or power up the AD
pins are configured by software as AD inputs. To change those to
digital IOs, the user must write to the appropriate PINSEL register.
The LPC1114 does not support an external reference for the A/D
converters.
The A/D input requires a
drive impedance of 7.5K or less (see NXP LPC175x spec sheet). We've also
found a
100 to 1000 pF cap from AD input to GND
can remove high frequency noise affecting high order bits in the
converter.
Analog Isolation
TBD.
Power connections -- SuperPRO
The board is shipped with a USB mini B
type female connector for power, it is not a USB port. With the wide
availability of USB chargers, this is
becoming the most cost effective method of powering small
electronics.
Diode steering allows power to be supplied
from 5V USB, the USB test connector, or the battery connector.
Because of the Schottky diodes, all 3 power sources can be connected
simultaneously.
The schematic below describes this circuit
on the PROstart
Power connections details
The 3.3V regulator can
supply 50 mA, with most being used by the LPC2103. The 3.3V connection next
to RESn on the lower power connector is only connected if the shorting pads
are shorted (NOT the factory default).
The analog GND should be
used to connect to the GND of analog inputs. Digital and Analog GNDs are
connected together with a small trace, but to minimize noise you should use the
analog GND only for analog signals.
Jumpers and
test connector for Program Download
The USB Dongle from Coridium will supply
5V from the USB to power the PROstart. It also controls the RESET and BOOT
signals to automatically load C or BASIC programs using MakeItC or
BASICtools. Remember, if you load a C program, it will erase the BASIC
firmware and you will not be able to load BASIC programs after that.
When using the SparkFun FTDI Basic Breakout
Board, a limited amount of power can be supplied from the BBB, but this is
limited to 50 mA and after diode drops, its about 2.8V to the LPC2103. In
practice this will run, but it is outside the part specifications, so it
should be limited in use.
Also with the SparkFun FTDI Basic
Breakout Board to load a C program, the LOAD C jumper needs to be installed,
then removed to run the program. BASIC programs can be loaded and
controlled using the SparkFun board, with no additional steps/jumpers.
An alternative is to use a 2 pin header
with a shorting block (pictured below)
