Not every 2.2u board is equal

[kirkb4989]

Hi,

I was trying to put together a BOM for the bare boards for the 2.2u DIY boards I just bought from your store. I see you state that one can generate a BOM from the Eagle SCH and BRD file and that is true, HOWEVER, the 2.2u board in the Github does not match the 2.2u boards I received (the picture here: http://rayshobby.net/cart/pcb_osdiy22?search=2.2u matches my boards)!

The 2.2u DIY board in Github has the ATMEGA at 16MHz and uses a different voltage regulator chip for the power. The board I got looks closer to the 2.1 board as far as layout (it uses the same LM2596 buck coverter) but I am concerned about OTHER parts differences.

Is there a board and schematic file for the 2.2u board I received rather than the incorrect 2.2u schematic on Github that appears newer???

Thanks!! Kirk

[Ray]

Sorry about the confusion. There are two slightly different versions, as the two sets of files in Github indicate:
https://github.com/rayshobby/opensprinkler/tree/master/OpenSprinkler%20Controller/hardware/v2.2/diy
I am pretty sure what you should be looking at is the os22_diy, not the os22_rev_diy. The difference between them is mainly that the former uses LM2596 regulator while the latter uses MC34063. The crystal for both versions should be 16MHz (the schematics say 12MHz, which is a mistake — 12MHz is what OS 2.1 uses). The voltage regulator on your PCB is MCP1700-33 (small, SOT-23 type).

[kirkb4989]

Ahhh! I totally missed that version on the repository. It sure does seem to match!! I am pretty good at SMD soldering so I should have no issues building this- I already have most of the parts on hand.

Thanks!!!

[TheDeadly1]

Is that 16MHz crystal for both the CH340 and the ATMega644?

[Ray]

No, CH340 uses 12MHz and it’s a small surface mount component. ATmega644 uses 16MHz. ENC28J60 uses 25MHz.

[Author]

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