Wireless LCD display

From Just in Time

A wireless LCD display based on a standard LCD display (4x20), a cheap 433Mhz transmitter/receiver pair and an SX.

original SX print for the wireless display, showing the SX, a regulator, resonator and "programmer pads" where the SX-Key device is pressed. The 433Mhz receiver is not shown in this image.

The original version of this device was developed on an SX. This firmware includes an implementation of a packet-based protocol on top of rs-232. The protocol allows for addressing and includes a 16-bit checksum (xmodem). This protocol was developed to allow transmisions along a very unreliable medium. Essentially, the protocol is quite simple though: when a package fails checksum verification, it is discarded.

In the mean time, we've switched to AVR and the wireless lcd protocol has been ported to ATTiny2313. Now, the same protocol is used for our remotely controlled RGB par spot and for the Oven temperature controller project.