Echelon Mini EVK - Manual (Page 48)

Document Title Contents Part Number
Scanning a Keypad
with the Neuron Chip Describes how a Smart Transceiver or
Neuron Chip can be used to scan a simple
16-key switch matrix to provide a numeric
or special-function keyboard without the
use of a keyboard encoder.
005-0004-01
Using the Hardware
Serial Peripheral
Interface (SPI) and
Neurowire I/O Object
Models to Interface
with
Peripherals and
Microcontrollers
Describes communications between Smart
Transceivers or Neuron Chips and other
microcontrollers for designs that intend to
make use of the SPI interface for simpler
applications and also for understanding
how the SPI interfaces are implemented in
the Smart Transceivers and Neuron
Chips. Neuron C code examples of an SPI
interface are explained in this engineering
bulletin, and the source code is available
for download.
005-0165
Digital Sensor Example
The following example function reads the push buttons on a MiniGizmo and
returns TRUE if any are pressed. The push buttons are connected to a 74HC165
8-bit parallel-in/serial-out shift register. Data is shifted on the Smart
Transceiver IO4 (clock) and IO5 (data) pins, with a latch strobe on IO6 (active
low to capture). The push button readings are debounced under application
control.
// Configure the I/O pins
IO_4 input bitshift numbits(8) clockedge(-) ioButtons;
IO_6 output bit ioButtonLd = 1;
// Read the MiniGizmo buttons
boolean GetButton(void) {
// Latch the button inputs
io_out(ioButtonLd, 0);
io_out(ioButtonLd, 1);
// Shift in and return TRUE if any buttons are pressed
return !((unsigned) io_in(ioButtons) == 0xFF);
}
Analog Sensor Example
The following example function reads the temperature sensor on a MiniGizmo.
The enable_io_pullups compiler directive is required when using the
MiniGizmo temperature sensor. The temperature sensor is based on a 1-Wire
(“Touch I/O”) Dallas DS18S20 digital thermometer. The Touch I/O interface is
connected to the Smart Transceiver IO7 pin.
#pragma enable_io_pullups
// Configure the I/O pins
IO_7 touch ioThermometer;
IO_10 output serial baud (4800) ioSerialOut;
42 Mini EVK User’s Guide