Control and I/O boards

To test a product you need to connect it and then control and measure different aspects of it. We sell standardized control and I/O boards that we have developed based on requirements coming from in-house test fixture construction. The boards are used in our own test fixtures, which ensures the correct functionality, price and quality. 

With these boards you can supply the device under test (DUT), measure current consumption, program the flash memory, control inputs and measure outputs, test/calibrate the frequency and output power of a radio transmitter, test LEDs etc. Moreover the boards can be used for product development with UART for debug prints and JTAG/SWD for debugging etc. Get in touch if it sounds interesting and we will tell you more!

Control board, MD-TF-RF-DAQ

The control board if the brain of a test fixture; it provides a large number of commands to control and measure different functions in the DUT. The picture below shows the control board MD-TF-RF-DAQ.

A key feature is the ability to measure radio transmitter frequency and output power, and to generate radio signals; normally this requires very expensive instruments. These are just a few of many functions. The block diagram below shows the various functions. 

The control board provides four serial channels, and is connected to the computer with a USB cable. Two channels are used for flash programming while the other two are used for serial communication with the control board and the DUT respectively. The control board offers a serial command line interface (CLI) that is used to invoke different functions in the board. Normally the DUT is also controlled through a serial CLI.

The following functions are available:

  • Power supply - supplies configurable voltage and max-current to the device. Aborts if the current consumption is too high, e.g. at short circuit, see fuse below.
  • Current meter - can measure micro-Amp currents and upwards.
  • Fuse - configurable "soft" fuse that measures current continuously and aborts the power supply if the max-current is exceeded. Is backed by a "hard" fuse that cuts if the soft fuse is not fast enough.
  • Flash programmer / debugger - supports JTAG, SWD, 8051 etc. Works with OpenOCD. Drivers are provided.
  • RF Spectrum Analyzer (SA) - measures frequency and output power of a radio transmitter.
  • RF Signal Generator (SG) - generates a radio signal to test a radio receiver.
  • RF Packet Transceiver (TRXER) - can send and receive packets to measure BER and PER.
  • I2C for I/O Expansion - bus that is used to connect peripherals on the I/O board, e.g. I/O expanders and sensors etc.
  • Digital inputs and outputs (GPIO).
  • Analoga inputs and outputs (ADC/DAC).
  • Etc.


The main purpose of the I/O board is to connect the device under test (DUT). This is done by connecting the I/Os of the board to the test needles/probes that connect to the DUT test points. The picture below shows the I/O board MD-TF-DAQ-ADPT.

The I/O board is designed to be generic and cover as many test cases as possible by offering a sufficient number of I/Os. It is connected to the control board to expand the number of available I/Os through the expansion bus. The board provides the following functions:

  • 8 digital inputs, DIN00-DIN07, 0-15V.
  • Frequency divider that enables frequency counting on DIN00 or DIN01.
  • 8 digital outputs, DOUT00-DOUT07, up to 5V.
  • 8 digital outputs with high supply capabilities, POUT00-POUT07, 3A +15V.
  • 12 analog inputs, AIN00-AIN11, 0-12V.
  • I/Os to control the status interface of the test fixture - LEDs, button, button illumination and lid sensor.
  • Buzzer.
  • 4 light sensors (for testing LEDs).
  • Microphone input.
  • Temperature and humidity sensor.
  • Etc.