The Uni-Byte D-Axe IlI is primarily intended as a rapid prototyping tool for PICAXE® 8, 14 and 20 pin microcontrollers. It is designed to offer professional level handling and the ability to directly attach popular and commonly available 3-wire sensors and actuators. This modular approach to prototyping allows proof-of-concept quality prototypes to be put together in a matter of hours instead of days or weeks. However, it has many features which provide ease of handling, quick set-up and robust operation and ensure it can easily be utilized as a programmer or in a more traditional development role as well.

Connecting to the Host Computer

The D-Axe II is equipped with a standard 3.5mm stereo jack and can be connected to the host computer with either an AXE26® serial cable or an AXE27® USB cable. These cables can be purchased separately from your D-Axe II dealer. If you choose to go ahead with the AXE27® USB cable, please refer to the documentation at: http://www.picaxe.com/Getting-Started/Driver-Installation/ for instructions on how to install and configure the driver.

Inserting the MCU

Make sure the lever on the ZIF socket is in the vertical position; place the MCU into the socket with its pin 1 adjacent to the Pin 1 indicator on the board. Pin 1 is that pin closest to the ZIF socket lever. While steadying the board with one hand, lower the ZIF socket lever to the horizontal position using the index finger of your other hand. Whether you are using an 8 pin, 14 pin or 20 pin MCU, it is always inserted such that pin 1 of the MCU is aligned pin 1 of the ZIF Socket. 

Attaching the power

The on-board regulator and standard DC barrel jack allow for a variety of power options. Any filtered DC source of between 8V and 20V can be used. Make sure the chosen power supply delivers positive voltage through the center conductor and negative through the outer sleeve (center positive).

Building Prototypes

The main design feature of the D-Axe IlI is it ability to directly attach sensor and actuator modules without any additional circuitry or connectivity boards.  These modules, commonly know as ‘bricks’, use a 3-wire connection to the host controller. The three wires carry  Signal, supply Voltage and Ground, and terminate in a standard 3-pin header connector. These can be directly attached to the headers on the D-Axe III where each signal from the MCU is brought out and mated with a 5v and ground pair. As indicated by the markings on the headers, signal is the pin closest to the MCU socket, supply voltage is in the middle and ground is on the outside. Generally speaking, the connectors are not keyed and there is no discernable standard to the coloring of the wires. However, White – Signal, Red – Voltage, Black – Ground is a common. As well, placing Voltage between Signal and Ground virtually assures that damage to a module is unlikely. That not withstanding, it is advisable to consult the documentation supplied with the module to ensure connections are made properly so that they function properly from the start. Or better still, design and build your own modules.