A Brief Examination Of The Hx300 Mini-Usb Connector - Standard Horizon HX300 Programming Manual

2.1 A brief examination of the HX300 mini-USB connector

Standard Horizon opted for a mini-USB connector both for charging and for program-
ming the HX300 radio. The charging takes place using the Vcc and ground lines of the
mini-USB connector. It is important to emphasize that programming the radio does not
utilize normal USB data transfers and that a normal USB/mini-USB cable cannot be used
to program the radio.
The mini-USB connector contains five pins:
Vcc +5V DC. Used only for charging the HX300.
Ground Used for charging the HX300 and as signal ground reference (GND).
Data+ TX at the radio end (TTL signal levels at 5V).
Data- RX at the radio end (TTL signal levels at 5V).
ID Not used with the HX300.
The TX ("Data+") and RX ("Data-") lines as well as GND are required for program-
ming the HX300 radio. Note that the "Data+" and "Data-" notions only apply to the
pin names in the mini-USB connector — they are not the actual signal names as used in
a "proper" USB interface.
Figure 4: The pinout of the mini-USB connector. Note that wire colors may vary.
A mini-USB cable can probably be scavenged from the parts bin. It will need a slight
modification as shown in figure 5.
Figure 5: The mini-USB connector about to face its final destiny. Note that wire colors may vary.
From here on, proceed either via the CT-99 route (if you already have access to the
mentioned cable assemblies) or the FTDI Friend route (if you first need to go shopping).
http://www.annoyingdesigns.com/HX300 5