HID keyboard with synced external actuation.
The purpose of this project is to solve the problem of visual art performers who need to synchronize a video clip with some external actuations such as lamps, pumps, motors, whatever can be managed by a relay.
The firmware acts as a normal USB HID keyboard: when pressing the button, a defined key (tyipically space-bar) is sent to the connected device (PC, tablet, smartphone) so to start the video clip. A timer synchronizes with the button press so that an external supply can be turned on or off after a defined interval.
In this way, it is possible to synchronize the driving of external loads with whatever video clip.
- Nucleo-F042K6 board
- Relay board
- Buttons
- LED holders
- USB cable
The project targets a Nucleo-F042K6 board from STMicroelectronics but can be easiy adapted to any STM32 with USB device capabilities.
| Signal | STM32 IO | Nucleo connector |
|---|---|---|
| Button | PB5 | CN3-14 [D11] |
| LED | PB1 | CN3-9 [D6] |
| Relay | PB7 | CN3-7 [D4] |
| Spare OUT | PB6 | CN3-8 [D5] |
| Spare IN | PB4 | CN3-15 [D12] |
| USB DP (Green) | PA12 | CN3-5 [D2] |
| USB DM (White) | PA11 | CN3-13 [D10] |