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
IN, OUT... keywords
. For port
1 pins are accessed with IO(32) through IO(41).
IO(4) and IO(5) are
open-drain outputs, so for those to go high, you need to have
a pull-up resistor (1K to 10K
are good values, depending on the speed required).
The LPC1114 supports a number of dedicated functions. Those
include 4 timers, 2 SPIs, and I2C.
In
addition most can be configured with pull-ups
or pull-downs and default to pull-ups following reset.
Details can be found in NXP's User
manual.
Analog connections
6 A/D converters are readily available, Analog 0-5.
On reset or power up the AD
pins are configured by software as AD inputs. To change those to
digital IOs, use IO(11), IO(32) through IO(36). Those pins will remain
digital IOs until
the next reset or can be
changed back to A/D by writing to the 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).
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
150 mA, with 10 mA being used by the LPC1114.
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 or FTDI cable will supply 5V from
the USB to power the PROstart. The Coridium USB dongle 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 LPC1114. 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 or FTDI
cable to load a C program, the LOAD C jumper needs to be installed, then removed
to run the program. The Coridium USB dongle controls the BOOT signal
so C programs can be loaded without the jumper.
BASIC programs can be loaded and controlled using the Cordium USB dongle,
FTDI cable, or SparkFun board, with no additional steps/jumpers.
An alternative is to use a 2 pin header
with a shorting block (pictured below)
