Case Studies

Electronics and Firmware Design for the PolyScience DuraChill

Posted in Consumer Goods, Embedded Development & Programming, Product Development


PolyScience is a leader in temperature control solutions. They have manufactured a variety of heating and cooling systems since 1963 and have sold over 1 million of these products. DMC has worked with PolyScience to design the electronics and firmware for their newest line of high performance chillers, called DuraChill Portable Recirculating Chillers

The key goals of the electronics and firmware upgrade were to further enhance the temperature control performance, incorporating an easy-to-use touchscreen interface, improving long-term reliability through intelligent fault handling and automatic maintenance, and developing an on-board self-testing procedure for simplified diagnostics.


The DuraChill is a refrigeration unit that pumps and cools circulating fluid to a precise constant temperature. These systems get used in a variety of different industries, including biomedical, pharmaceutical, chemical, scientific, and many more.

The solution was built around an STM32 ARM Cortex-M4 microcontroller. This microcontroller featured hardware support for driving the full-color touchscreen that is featured prominently on the front of the unit.  We leveraged a graphics library called emWin to create the user interface. This library features a rich set of menus and status screens that allows the customers to configure the end device to their needs.

With a system this advanced, there are many opportunities for updates and further improvements to the device, which is why it features a secure USB bootloader.  DMC worked closely with PolyScience to implement their custom high precision temperature control algorithm. The custom control algorithm relies on a variety of control inputs to make the proper control response. These controls include high-precision temperature measurements using RTDs as well as a variety of sensors requiring precise voltage, current, and frequency measurements. The system also required control of pumps, compressors, fans, and precise stepper valves.

The new system provides features including warning and faults that give the user quick audio and visual feedback on any issues. The system also will act to mitigate any damage potentially caused by these faults. Users can always confirm their DuraChill chiller is operating at top performance using the diagnostic self-test mode. This mode provides the user with a way to easily compare the current performance of the chiller to its performance measured in the factory. This factory data is all stored in the device's onboard memory for the lifetime of the chiller.

Learn more about DMC’s Embedded Development and Programming Services.

Customer Benefits

  • Best-in-class temperature control performance
  • Full-color user interface
  • Multi-language support
  • Internal systems diagnostics
  • Automatic maintenance features
  • Fault and error handling to increase the lifespan and robustness of the device
  • Variety of communication protocol


  • STM32 ARM Cortex-M4 microcontroller
  • Mbed OS
  • Full-Color TFT touch screen display
  • Rich graphical interface based on emWin library featuring multi-language support
  • Secure USB bootloader featuring encrypted, signed firmware updates for future updates
  • USB Host for data logging and firmware updates
  • USB Device featuring custom serial communication protocol
  • RS232 serial communication protocol
  • High-precision temperature measurements using RTDs
  • AC Power Analysis for diagnostic purposes
  • Environmental sensors for ambient monitoring
  • Precision control of stepper motor valves