USB/RS232 Input Controller – 8 Inputs

The ATE-501 is a modular controller with 8 inputs. It can be controlled via USB or RS232 with simple ASCII commands.



  • 8 Inputs with 10K pull-up resistors
  • Inputs are protected to 30Vdc max.
  • 8 Inputs can measure analog and digital signals
  • Connections via screw terminals
  • Arduino software compatible
  • Control with ASCII commands
  • USB virtual COM with FTDI adapter or cable
  • Powered via USB or via screw terminals
  • Dimensions 10 x 8 x 2 cm (approx.)
  • Open source hardware and software


The ATE-501 Input Controller consists of ATE-101 Carrier Board with Arduino Pro Mini and ATE-202 Input Boards with 8 inputs, which should be assembled as shown in the picture.


The ATE-202 Input Board has 8 inputs and one common connected to ground. The board can be used to measure analog and digital signals. Analog 0V until +5Vdc. In the firmware digital logical level 0 is set at +0,5Vdc or less and logical level 1 at +2Vdc or more.
The inputs have a 10K pull-up resistor to +5Vdc. A switch contact can be connected directly between input and GND (dry contact input). Also an open collector output can be connected directly to the input.
For USB connection the FTDI Basic USB Board can be used or the FTDI USB Cable.

You can use an RS232 to TTL adapter instead of FTDI USB, to get an RS232 control.

Power input is not connected. Power input can be used as an alternative input to supply power to the Arduino Pro Mini. In this case jumpers on both boards must be changed. See the schematics for information on jumper settings.
The analog inputs use the power supply of the microcontroller as reference. If you need a more stable reference, you can use this Power input to supply only the microcontroller.

Power Supply

The ATE-501 is powered via USB. The input board and Arduino Pro Mini have a power on led.

Jumper Settings

For USB power via the input board. The jumpers settings should be as on the photos above:
ATE-101: 4-3 5V
ATE-202: 5-6 5V, 9-10 USB

Loading Firmware

The ATE-501 uses the Arduino Pro Mini (5V) which is an Atmel ATmega328 microcontroller with Arduino bootloader. You can load the code via USB into the Arduino Pro Mini with the Arduino development environment, available at Before loading it is recommended to place the 10-9 Auto Reset jumper on the ATE-101 Carrier Board.


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