The Hx300 Usb Interface - Standard Horizon HX300 Programming Manual

2 The HX300 USB interface

Communication with the HX300 for programming purposes takes place using serial
communication at 19,200 and 57,600 baud, utilizing TTL voltage levels at 5V.
The USB-62B USB cable assembly readily provides TTL voltage levels. A USB-62B-
like cable assembly is available from RT Systems, Inc., listed as the CT-62 [5]. The orig-
inal Standard Horizon CT-172 cable assembly seems to be a bit harder to get hold of.
Luckily, the original CT-172 is not really required for programming the HX300 radio.
Other interfacing options include the FTDI Basic Breakout from SparkFun Electronics,
Inc [7] and the FTDI Friend from Adafruit Industries, LLC [1] which will both provide the
required TTL voltage levels and a serial port via USB. Similar TTL/serial port via USB
breakout units (5V) are also available from eBay [3] at very reasonable prices.
Also, owners of the Standard Horizon CT-99 cable assembly can easily use jumper
wires to hook up to the USB-62B for programming the HX300. Either way, a mini-USB
connector is required for connection to the HX300.
Figure 2: The HX300 mini-USB connection. Illustration from HX300 user's manual [9].
Figure 3: The Standard Horizon CT-99 cable assembly which will attach to the USB-62B.
http://www.annoyingdesigns.com/HX300 4