The A104 is a
16-bit PC/104 form factor (mechanical/electrically compatible)
microcontroller. It is designed for embedded applications that
require compactness, low power consumption, and high reliability.
Measuring 3.8 by 3.6 by 0.5 inches, the A104 offers a complete C/C++
programmable computer system with a high performance CPU (188) and
operates at 40 MHz system clock speed with zero-wait-state. It
features up to 512KB ROM/Flash, 512KB battery-backed SRAM, 512 bytes
serial EE, a real-time clock, three 16-bit timers/counters and a
Two DMA-driven serial ports and a third SCC2691 UART support
reliable serial communication up to 115,200 baud. On-board drivers
support three RS-232 ports, or two RS-232 and one RS-485 port,
supporting either normal 8-bit or 9-bit multi-drop RS485/422 network
with twisted-pair wiring.
There are three 16-bit programmable timers/counters and a watchdog
timer. Two timers can be used to count or time external events up to
10 MHz. They can also be used to generate non-repetitive or
variable-duty-cycle waveforms as PWM outputs. The Pulse Width
Demodulation (PWD), a distinctive feature, can be used to measure
the width of a signal in both its high and low phases. This has
potential in a variety of applications, such as bar-code reading.
The 32 I/O pins on the Am188ES are multifunctional and
user-programmable. You may have 15 or more lines free to use,
depending on your application.
Also on-board is a PPI (82C55) chip providing an additional 24
bi-directional I/O lines that can be used to interface to an LCD and
a keypad. An adjustable negative voltage (-10V) is on board for LCD
A 64 pin 8-bit PC/104 connector can be installed. The A104 is not
fully PC/104 compatible; bus signals are routed to the connector
directly from the CPU with no buffering. No software support is
provided for direct interface to other PC/104 products.
The 12-bit ADC has sample and hold, a high-impedance reference
input, 11 single-ended 0-5V (or 0 to REF) inputs, and a 10 kHz
sample rate. A 24-bit Sigma-Delta ADC (AD7731, Analog Devices) can
also be installed. It has five inputs with programmable gain front
end, which allows it to accept a range of low level transducer
signals. At 800 Hz-output rate, the achievable resolution is 16-bit,
based on the AD7731 datasheet.
Two 12-bit DAC provides 0-4.095V analog voltages outputs capable of
sinking or sourcing 5 mA. The 14 solenoid drivers are capable of
sinking 350 mA at 50V, perfect for driving solenoid coils or power
The A104 provides its own voltage regulator and RS232/RS485 drivers.
The A104-S supports six RS-232 and one RS-485 serial ports,
including two optional SCC2692s. It offers 80+ I/Os. It does not
support the 24-bit ADC, solenoid drivers, and one of the DAC chips.
If you're looking at the A104-S primarily for its serial-port
capabilities, also take a look at the
UART-8 serial port
expansion controller. It provides 8 additional RS-232 ports, and can
be easily interfaced with most TERN controllers.
- Two SCC2692 + RS232 drivers (four RS232 ports)
for a total of six RS232, and one RS485
- Does NOT support 24-bit ADC, solenoid
drivers, and one of the DAC chips
Similar controllers: V104,
Expansion boards: MemCard,