User Manual

LockitModule Version 0.9 (18.10.2021) Page 8 of 17
Exemplary implementation of pull-up resistor
3.4 Communication Interfaces
2 physical host interfaces, UART and USB HID, are available to control and inquire status of the
module. The API documentation is available as separate document.
UART
Pin
Name
Type
Description
21
UART_RX
D
3.3V TTL, 5V tolerant
23
UART_TX
D
3.3V TTL
The serial 3V TTL UART1 interface is the most preferable interface for low level connection. A level
shifter will be required for communicating over RS232.
USB
Pin
Name
Type
Descripti
on
15
USB_D_P
D
USB data line, full speed
17
USB_D_N
D
USB data line, full speed
19
USB_VBUS
PWR
5V +/
-
5%, source to be in compliance with BC 1.2
For host systems with USB HID support this interface offers higher data rates and additionally makes
the timecode available as MIDI device. Controlling the device is possible via a terminal program using
the same API as over UART. Having the USB connection accessible when not in use for configuration
offers easy updating of the firmware using the readily available LockitToolbox utility.