EPD 1.54 Inch 200x200 E Ink Display Screen SSD1681 Driver 4-Wire SPI Thermostat Panel Module

A thermostat must be legible at night, invisible as a light source, and cheap enough to leave on for years. Electrophoretic e-paper fits: microcapsules hold charged black and white pigment, plus red and yellow layers in the four colour build; a pulse moves the chosen colour to the surface and the pigment stays without holding voltage. A reflective surface means the panel is lit by the room rather than lighting it, so a bedroom wall plate does not glow. This 1.54 inch module puts 200x200 pixels on a 27 x 27 mm area behind a 0.98 mm thin outline, driven by the SSD1681 over 4-wire SPI.

Room thermostats show a setpoint and a mode icon. HVAC zone controllers show a room name and a schedule step. Boiler front panels show a flow temperature and a fault code. Water and gas meter heads show a reading and a unit. Air quality monitors show a particulate number with a colour band. Radiator valve displays show a target temperature. Each of these shows a number and an icon that change a few times a day at most.

The gain here is thermal and electrical. A reflective screen emits no light spill in a bedroom, which is the complaint that drives most thermostat display changes. The 2.18 g panel adds almost nothing to a wall plate that must hang on plasterboard fixings. Red and yellow layers give an alarm or boost state a colour cue without adding an LED and its current. Standby current drops to the sleep figure of the host MCU, which is what makes a battery thermostat viable without a common wire.

The panel paints setpoints, schedules, mode icons and warning fields in four colours, refreshes on demand over 4-wire SPI, supports partial refresh so a one degree change does not flash the whole screen, and retains the frame through brownouts. That last property matters in a heating system: a boiler ignition can dip the rail, and an LCD would blank while an e-paper panel keeps the last reading.

Fit the panel behind the thermostat bezel, connect the 24 pin FPC, apply VDD 1.8 V and VCI 3 V, send the SSD1681 initialization table, then draw a full frame and refresh. Afterwards use partial refresh for setpoint nudges, and re-run a full refresh after any power loss. Confirm that the bezel window does not press on the film, since pressure shows as a permanent grey patch.

Operate between 0 and +50 C only, and keep the rear of the panel away from the boiler hot side, because heat above the rating degrades contrast and accelerates the edge seal. Avoid condensation when a cold unit enters a warm room, protect the FPC stiffener from bending, and never hot-plug the connector while powered.

Shipments leave 5-10 working days after payment, with courier service for pilot builds and air or sea consolidation for production runs. Test reports and packing lists accompany every carton, and monthly capacity is about 100,000 pieces.

T/T, L/C at sight and Western Union are accepted; samples are prepaid and production orders follow a deposit plus balance against shipping documents.

Panels arrive with protective film in anti-static trays, foam corner guards, a moisture barrier bag and an export carton, so units reach an assembly line without edge chipping.

Minimum order is 10 pieces and samples can be sent for bezel fit checks. Arrival defects are replaced after photo confirmation, the 12 month warranty applies, and our team reviews bezel drawings, refresh intervals and low temperature behaviour before release.