this post was submitted on 21 Mar 2024
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Greetings! I've been throwing this schematic together as I want to experiment with the TI LP5812 IC which is an i2c controlled autonomous matrix LED driver. I am a novice when it comes to electronics so I'm looking to see if I've missed anything in this demo board schematic.

The intended purpose of this circuit will be to provide a playground to experiment with different lighting patterns by allowing the user to interact with two of these LP5812 ICs over i2c as each can only drive 4 RGB leds each.

My main points of concern: Making sure that I haven't missed anything critical in the rather dense TI datasheet https://www.ti.com/lit/ds/symlink/lp5812.pdf?ts=1710689049125 as well as making sure that my schematic makes sense.

I chose not to include i2c pullups on this dev board as I felt that was best left for the host to configure, but I'm happy to learn. Thank you!

Here's a link to the KiCad project if you'd like to see more https://github.com/scytherswings/Starlight-LP5812-Dev-Board/tree/main

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[–] glarf@lemmy.world 2 points 7 months ago

Naturally, just like a making a pull request, I found that my annotations were incorrect for the LEDs (it doesn't functionally change the schematic) after posting. My intent is to have all odd LEDs on U1 and even on U2 so that when I place them in a circle it's easy to make usable patterns with one controller at a time as I learn how to use animation engines.

[–] thantik@lemmy.world 2 points 7 months ago* (last edited 7 months ago) (1 children)

Other than maybe integrating pullup resistors into the board, I can't see anything. The datasheet 9-1 Typical Application shows 2x 4.7k pullups; but you may be planning on tackling that elsewhere.

[–] glarf@lemmy.world 1 points 7 months ago* (last edited 7 months ago)

Yeah I hear that some people like to keep the bus pullups closer to the host. The other gotcha is that the voltage for the I2C doesn't have to match the VCC pin and I didn't want to assume that users would want those coupled together. Perhaps I can add some DNP resistors so users can have a choice of a pull-up on the dev board if they like.