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A low-priced UPS costs approximately 10 hours of operational time and requires a replacement PCB.
Homeowner Discovers Retrofitting Solution for Serioux LD600LI UPS
A homeowner, identified as Florin, recently faced issues with a budget-friendly uninterruptible power supply (UPS) purchased from Serioux, specifically the LD600LI model, when it came to integrating it with a smart home setup using HomeAssistant (HA). A closer inspection and subsequent fix revealed compatible hardware components and a detailed process to ensure seamless UPS functioning.
Initially, the UPS communicated with HomeAssistant via Network UPS Tools over a generic USB protocol. However, HomeAssistant frequently lost the connection with the UPS, jeopardizing its integration in the smart home system. A thorough examination of the UPS revealed the primary culprit to be a less-than-ideal USB interface, rather than the UPS's incapability to manage power issues.
Upon disassembling the UPS, Florin found a common USB-serial adapter belonging to the Cypress CY7C63310 family, which seemed to lack the necessary firmware to handle the job effectively. To resolve this problem, a replacement of the USB controller was in order.
Florin implemented a solution involving the use of Silabs CP2102N USB-to-UART controller and the HopeRF CMT8120 dual-channel digital isolator. The process involves connecting the 9600 baud serial link from the UPS main board to the Silabs CP2102N USB-to-UART adapter to create a virtual serial port on the USB side. This conversion board requires complete isolation, thereby necessitating the use of the HopeRF CMT8120 digital isolator.
Almost seamless functionality was achieved with the assembled components; the only drawback was an apparent conflict with a Sonoff Zigbee controller in the smart home setup that also utilized the same Silabs controller. Silabs AN721 provided a remedy, offering an alternate PID (0xEA63) to avoid the issue.
In total, the cost of a $40 UPS equated to 10 hours of work and $61 in hardware costs, suggesting that repairing and retrofitting might not be the most economical option. Nevertheless, the effort rendered invaluable lessons and insights into the process, allowing others to learn and potentially improve upon the endeavor.
Additionally, leveraging a microcontroller like an ESP8266 or ESP32 would offer a more flexible and network-friendly solution, ensuring reliable UPS monitoring compatible with HomeAssistant and similar systems. This method includes using ESPHome or ESPLink firmware on the microcontroller to expose the UPS data as a TCP stream and integrating the data into HomeAssistant or other networked devices. Although not directly included in this particular project, utilizing such an approach offers potential benefits in terms of reliability and compatibility.
The homeowner's findings indicated that the UPS, the Serioux LD600LI model, could be improved for integration with smart home technology. A USB-serial adapter inside the UPS, belonging to the Cypress CY7C63310 family, was replaced with a Silabs CP2102N USB-to-UART controller and HopeRF CMT8120 digital isolator to enhance the UPS's communication with data-and-cloud-computing systems like HomeAssistant.
