B4J app for measuring voltage and frequency using Arduino Nano or Uno. The frequency is counted over 1 second by dividing the 16MHz crystal, the ATMEGA328 can count up to 6MHz.
The Arduino connects to the PC via USB.
Private fx As JFX
Private MainForm As Form...
The code doesn't use any library, the SPI is set by inline C. Using 1.8" TFT with ST7735 driver, displaying universal 5x7 fonts for 0 to 9. The code works only for ATMEGA328, I used Arduino Nano.
Voltage input at A0. Bitmap is BMP of 16 (5:6:5) bit color, it uses about 85% of the RAM.
It's good to talk.
Voltmeter app in B4A using Text To Speech.
Voltage input is at pin A0.
Arduino connected to Android via OTG cable.
The talking voltmeter has an adjustable timer to set the talk intervals (5 to 105 sec) and a stop button.
Optional pushbutton at pin 2 of the Arduino triggers...