How many milliamps does the Zymkey draw? I’m having a problem whereby I have an LCD 20x2 matrix screen in i2c mode connected above the Zymkey (same pins with an extender*). When the Zymkey is initialised and running, the LCD screen seems to very dim and unclear. But if I display something on the LCD display and do an OS shutdown and the Zymkey is de-activated the LCD screen is suddenly sharp and bright again?
*LCD is connected to pins 2 & 6 for power, and 3 & 5 for data.
The Pi is powered through its USB power supply with a 5V 2.5A supply.