Jonas Wühr

Developing a new FRDM NXP CUP-Shield

Blog Post created by Jonas Wühr on Jul 11, 2020

We took the free time during the Corona lockdown in Germany to create our own shield for FRDM evalboards, that is supposed to control autonomously driving robots ( especially NXP Cup vehicles ):


The board has the following features:


  • Power input with PTC fuse and reverse polarity protection ( 6 - 15V DC )
  • Control of two DC motors ( up to approximately 20A ) with current sense, motor fault detection and back emf measurement ( for rpm control )
  • Control of two Servos at 6V DC with adjustable maximum current
  • HMI with 2 potentiometers, OLED Display connection, 8 dipswitches, 4 LEDs and two push buttons
  • Reset button
  • Power control LEDs  ( 3V3, 6V and VBAT )
  • SD-Card slot
  • Connector for HC-SR05/6 Bluetooth module
  • Connectors for 2 linescan cameras
  • Connectors for 2 wheel encoders
  • breakout headers for 2.45 soldering breadboard on top side


Furthermore our shield is backwards compatible to the FRDM-TFC shield, so You can easily adapt already existing code to the new shield.


During the last weeks we assembled the very first prototype and tested it on an Alamak car with the FRDM-KL25Z:


top side

bottom with kl25z

bottom with bluetooth module


We had some smaller issues that could be solved with some jumper wires , but after all everything seems to work reasonably well .


Next week we will order the redesigned version and also publish the KiCad project and other documentation on GitHub.

You can already view the schematics attached to this post.


We really wonder how the NXP Cup community is interested in our work and if there are some more features that should be added .


Best regards, Jonas Wühr and Lucas Bartosch

Deggendorf Institute of Technology