Challenge description with context - Design of Low-Cost HMI using TFT capacitive multi-touch screen and Low cost micro-controller. 2. Providing 32-mbyte storage 3. Modbus Master or Modbus Slave over RS-485. 4. Minimize production cost.
Problem - Modbus is de-facto open-source machine communication protocol. If we provide Low-cost HMI over modbus, many machine manufactures can be benefited. Currently, capacitive touch based HMI are too costly for small machine manufacturers.