Project Background
A Finnish technology partner worked with DAVOLIN on a keypad and display module for Posti outdoor parcel lockers. The final application was parcel collection in Finland’s Nordic outdoor environment, where users need a practical self-service interface in severe winter temperatures.
The project concerned the metal keypad and display module, not the complete locker. Outdoor deployment expanded where parcel collection could be provided beyond indoor locations, while making low-temperature operation and limited available power central input-module requirements.
The Challenge
The customer required operation and testing at −40°C, a 3 V supply and current consumption below 80 mA. Sleep/Wake behavior, backlight control and display operation needed to be coordinated within that power requirement.
The interface also had to support Finnish, Swedish and English. A compact keypad, OLED display, TTL communication and protection for the outdoor installation needed to work together; ordinary keypad options did not meet this combined set of requirements.
Reliable parcel-locker input at -40°C
Low-temperature performance, OLED integration, power consumption, TTL communication and multilingual operation had to fit one compact module.
DAVOLIN Solution
DAVOLIN developed a 92 × 265 mm module with a 304 stainless steel panel and keys, an OLED display and a TTL interface. Internal silicone waterproofing and protective coating on the PCB were incorporated into the IP65 module.
The 3 V design incorporated Sleep/Wake and backlight control, with current consumption below 80 mA specified as the project requirement. The display interaction supports Finnish, Swedish and English. OLED was selected for the project’s cold-environment and multilingual display needs.
Development began in January 2021 and included display-command debugging and joint engineering adjustments. More than three rounds of modifications and testing were carried out. In the documented cold test, the module continued to function after 16 hours at −40°C.
The power figure is the documented requirement. The cold-test result describes the stated 16-hour test and does not imply a wider certification.
Selected Product
Custom OLED Parcel Locker Keypad
A custom 304 stainless steel keypad and OLED module for Posti outdoor lockers through a Finnish technology partner. The 92 × 265 mm module uses TTL, IP65 protection and a 3 V design with Sleep/Wake and multilingual interaction.
Project Result
Following development and testing, the Finnish technology partner placed the first order for 215 pieces. The modules were delivered on time, received in June 2021 and then installed for the outdoor locker application.
The cooperation continued through follow-up purchases, including ongoing procurement through 2026. In October 2025, DAVOLIN visited Posti locker installations in Oulu, Finland, providing a view of the equipment in its actual outdoor application.
Posti is the end application in this case; procurement was through the Finnish technology partner.
Looking Ahead
Continued purchasing through the Finnish partner has extended the project beyond the first delivery. The established module combines the low-temperature, power-management and multilingual requirements of the outdoor locker application, providing a reference for future configuration discussions.
