Knowledge Base

Problem

A user wants to connect the EthoVision USB I/O Box (PTIO-0020) to an Arduino or other third-party device using RJ45 cables and needs the pin assignment to identify which wires carry TTL output signals and which are ground.

Details

The USB I/O Box (PTIO-0020) uses an RJ45 connector for TTL input/output. The RJ45 has 8 pins, and users need the pinout to correctly wire ground and signal lines to external devices such as Arduino microcontrollers. This information is not always clearly documented in the standard user-facing materials. Affected hardware: Noldus USB I/O Box PTIO-0020.

Solution

The RJ45 TTL pinout for the USB I/O Box (PTIO-0020) is as follows:

- Pin 1 = Ground
- Pin 2 = +18 V
- Pin 4 = TTL Input 2
- Pin 5 = TTL Input 1
- Pin 7 = TTL Output 1
- Pin 8 = Ground

When wiring to an Arduino:
1. Connect Pin 1 or Pin 8 (Ground) to the Arduino GND.
2. Connect Pin 7 (TTL Output 1) to the desired Arduino digital input pin.
3. Note that the TTL output voltage is based on the I/O Box logic levels — verify your Arduino input is compatible (most 5V Arduino boards can read the signal; use a level shifter if needed).
4. Do not connect Pin 2 (+18 V) directly to the Arduino — this voltage may damage 5V logic inputs.
5. For TTL inputs (sending signals into EthoVision from Arduino): use Pin 5 (TTL Input 1) or Pin 4 (TTL Input 2) with the appropriate ground reference.