Summary
DMC worked with Polyscience, a leader in temperature control solutions to develop custom control electronics and user interface for their General Purpose Water Bath upgrade. The Water Bath is a scientific temperature control product that has been developed to be the highest value premium digital unstirred water bath on the market.
Solution
PolyScience redesigned their popular General Purpose Water Bath with modern features while still maintaining core functionality that made it so successful. The update included adding a full-color display with more comprehensive error handling and alarms, and updated control electronics. This was accomplished while maintaining their highly reliable and proven control algorithms.


DMC designed the upgraded system around a Cortext-M0+ microcontroller. We leveraged the open-source graphics library LittlevGL to efficiently operate the full-color TFT display. This open-source graphics library can easily scale from large to small projects which allowed the creation of rich graphics despite the resource constraints of the device. LittlevGL also provided many useful UI elements out-of-the-box that allowed us to make rapid UI changes. Switching to a full-color graphical display also gave the end customer multi-language support and a more intuitive interface for controlling and configuring the device.
Customer Benefits
- Modern user interface with a full-color display
- Informative error messages and improved error handling
- Support for multiple languages
- Optimized design for modern features using low-cost components
- Cost-optimized PCB design for volume production
Technologies
- STM32 Arm Cortex-M0+ microcontroller
- Control of line-voltage AC loads
- Full-color TFT display
- LittlevGL graphics library
- Developed with Mbed OS
DMC also implemented the existing control algorithm to meet the same reliability and performance while providing additional diagnostic and tuning capabilities for the future. The control electronics were upgraded to modern, widely available components and additional circuitry was added to enhance the way faults and alarms were displayed and handled.
Features of the General Purpose Water Bath that DMC developed include:
- Display of actual and setpoint temperature simultaneously
- Programmable pre-sets for frequently used temperatures
- Integrated timer
- Calibration capability
- Primary and automatic safety thermostats


Learn more about DMC’s Embedded Development and Programming expertise as well as our Product Development services.
For more information on PolyScience’s range of temperature control solutions, please visit their website here.