Segmented LCD Driver HT1622/HT1621

[Sultanpepper123]

I've been leaning working on using and interfacing a microcontroller with an HT1622 + a custom segmented LCD. IMO the datasheet of the IC is very small and left me confused ; is the interface SPI ? UART ? GPIO and PWM (manually) ? . I've searched alot and found several tutorials and github libraries and they seem to not use the SPI feature.

So far (DATA) is MOSI  , CS is "CS" , WR is SCLK and RD is MISO ?  . 

 Any helpful advice/thoughts would make a world of difference. Thanks in advance.



Note : I've included some of my findings, hopefully someone might add in the missing pieces.

 1. Datasheet http://file.yizimg.com/332467/2009070510405297.pdf
 2. Arduino Uno example code https://github.com/kuwatay/Arduino/blob/master/Segment_LCD_HT1621/Segment_LCD_HT1621.ino
 3. Arduino tutorial for a chinese HT1621+LCD module http://arduinolearning.com/code/ht1621-6-digit-7-segment-display-example.php
 4. Another Tutorial on module https://www.instructables.com/id/How-to-Wire-the-6-Digit-7-Segment-24-Inch-Ht1621-L/

[ebclr]

It's a kind of synchronous serial but rely on RD and WR signals, also you need to handle when is data and when is comand,


This data sheet is very clear

https://www.holtek.com/documents/10179/116711/HT1622v270.pdf

[Sultanpepper123]

It's a kind of synchronous serial but rely on RD and WR signals, also you need to handle when is data and when is comand,


This data sheet is very clear

https://www.holtek.com/documents/10179/116711/HT1622v270.pdf

So its not SPI ? bitbanged IO implementation ?

[mikerj]

It's a kind of synchronous serial but rely on RD and WR signals, also you need to handle when is data and when is comand,


This data sheet is very clear

https://www.holtek.com/documents/10179/116711/HT1622v270.pdf

So its not SPI ? bitbanged IO implementation ?

Looks like you'll have to bit bang it.  It's somewhat SPI-like but has separate clocks for reading and writing with a common data line.  Pretty stinky tbh.