Author Topic: HPDL-1414 Display board  (Read 1064 times)

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Offline Roeland_RTopic starter

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HPDL-1414 Display board
« on: February 22, 2020, 08:52:06 pm »
936598-0Hi everyone,

I have created a small display board that uses 5 HPDL-1414 display modules. It uses I2C protocol (MCP23017-E/SP). The arduino code shows its simple to drive the display. The only problem I have is that the displayed strings are all in SRAM. I did try to store it in program memory using PROGMEM, but than all strings (character array[]) are corrupted, showing random characters. In my first attempt I used the String function instead of character array's. That was really horrible. It worked with one string, but after converting it to a function to send a string as parameter with it the arduino crashed because of memory problems. Now it works fine, but when I can use program memory there is more space for text to display. Next step is connecting an RTC module to the arduino showing the time. Sorry for the bad picture. Don't have a red filter.
Hope you like it.
You can watch a small demo here:
https://youtu.be/2wIKiKhokB8

« Last Edit: February 23, 2020, 08:47:04 pm by Roeland_R »
 

Offline Roeland_RTopic starter

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Re: HPDL-1414 Display board
« Reply #1 on: February 29, 2020, 08:08:14 pm »
Hi,

I have uploaded this little project to https://github.com/RoelandR/HPDL-1414-board where you can find the Kicad archive and arduino program for this display board. Software is for address 0x20, but you can modify it for other I2C addresses and chain to max 7 boards.
 


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