Imported from GitHub: variegated-coffee/open-lcc-board · commit dc47c11 · license CERN-OHL-P-2.0

Description

Schematics and PCB files for the Open LCC hardware

README

How to order and assemble

PCB and PCBA manufacturer

This directory contains Gerber files for the PCB, a BOM file with LCSC numbers for ordering with JLCPCB, and a CPL file. When ordering, it's highly recommended to also order a debug board. It is possible to flash the boards without one, but you'll have to solder on a USB cable to test points.

Orientations

Be careful with the orientation of the debug board FPC connector. Pin 1 is indicated on the board. When placed correctly on both the Open LCC and Debug board, you should use an FPC cable with connectors on opposite sides. If for some reason the connector is incorrectly oriented, you'll still be able to use the boards, but you may need an FPC cable with connectors on the same side.

If you have any doubt as to the orientation of the connector, it's a good idea to check for continuity between e.g. the USB D+/D- pins on the main board, and the D+/D- pins of the USB connector of the debug board before applying power. Applying power with reversed polarity can fry your board.

Orientations in general are a bit of a pain. I recommend checking the "Confirm production files" option on JLCPCB, to be able to verify that the orientations of all the components match the PCB and schematic.

Parts you'll need from other vendors

The BOM in the file isn't complete; you'll need a few other parts, some of which are hand soldered. Below is a table, including links to Digikey when the item is available there.

Of special note is the display. You can use either a Color TFT or an OLED. The OLED matches what's in the stock LCC, and is easy to install. The TFT requires some soldering skills to install, but is a lot higher resolution. Pick one. Also, at least the OLED (or rather a compatible one) is also available on Digikey, but it's a lot more expensive than on AliExpress.

Designator	Part name	Notes	URL (for one vendor, usually there are others)
J1	TE 280372-1	You can use a standard 2.54 mm pin header instead, but this is highly recommended.	https://www.digikey.se/en/products/detail/te-connectivity-amp-connectors/280372-1/2276004
SW1, SW2	Omron B3S-1000		https://www.digikey.se/en/products/detail/omron-electronics-inc-emc-div/B3S-1000/20686
J7	CH147QV01A	This is the Color TFT. Buy either this, or the OLED display, not both. Don't get the module, get the bare screen.	https://aliexpress.com/item/1005003771379232.html
-	WEO012864A	This is the OLED. There are a lot of different manufacturers for this. Make sure the pinout and pitch matches.	https://aliexpress.com/item/1005003108880951.html
-	05-24-D-0203-A-4-06-4-T	FPC cable to connect to Debug board	https://www.digikey.se/en/products/detail/gct/05-24-D-0203-A-4-06-4-T/21266839
-	AFAG2220-SW2	WiFi/Bluetooth Antenna (220 mm cable)	https://www.digikey.se/en/products/detail/abracon-llc/AFAG2220-SW2/9603584

Assembly

J1, SW1 and SW2 need to be soldered on. These are fairly easy to solder by hand, but be careful with the orientation of J1. It needs to match the orientation of the same header on the stock LCC. If you're using the TFT, that also needs to be soldered on, after which you should put kapton tape on the connector. You'll need to use double sided tape to attach the display to the board, but I'd recommend using a fairly tiny pad of it. That way, if your display is crooked, you'll probably be able to remove it without destroying it (speaking from experience).

The easiest way to flash the boards is with the debug board, which contains Micro-USB connectors for both the RP2040 and the ESP32-S3. It also has push-buttons for reset, RP2040 bootsel, and ESP32 GPIO0. Like I said, highly recommended.

Once everything is flashed, the board is ready to be installed.