Okay, two things: In all the disambiguation of the Yihua/WEP boards (major thanks to bitwelder), I'd started keeping notes regarding what board modifications certain boards would need. I figured I might as well review what I have, since it seems fairly well nailed down at this point. Also, this got me thinking that I should finish the half-baked "youde 858DV4" adapter I had started to lay out. In the end, I came up with adapter layouts for the other orphan boards. The
board/adapter index has been updated accordingly. Barring any errors in my work, this should tie up most of the loose ends in this thread.
REQUIRED BOARD MODIFICATIONSCertain boards require modification to be adaptable without major firmware changes. While the necessity for a given mod is described, the methods given are not the only possible way to remedy the problems. These are simply the methods implied by the specified adapter concept.
GeneralThe firmware expects some fan status input from all boards; these modifications are not board-specific. Each method will require some configuration of the code to select the sensing method and define/tailor the expected min/max ADC limits.
Fan voltage sensing can simply be done at the node connected to the positive pin on the fan connector (denoted by A). Others have recommended to connect to the positive-most end of the pot (B), though I don't see the advantage. Where ever the sensing is done, ensure that the selected divider resistors keep the ADC voltage within safe limits. Current sensing is done by adding a shunt resistor in the ground path of the fan and measuring voltage across it (C). Fan speed sensing requires extra circuitry to detect commutation noise, and is not covered here.
YH858D V2, V6 (Yihua/WEP)These boards use pins 17 & 18 for both button sensing and display element drive. The mod required by the existing adapters (wguibas' blue adapter) is as follows:
- Traces between pins 17, 18 and the display should be cut.
- Wire should be routed between display pins 7, 10 and the adapter board.
User wguibas has posted
instructions and images for adapting this board.
Additional mods: It may also be prudent to provide the TIP122 with a heat sink to keep Tj within allowable limits
YH858D V7,V8 (Yihua/WEP)These boards use pins 12 & 13 for both button sensing and display element drive. The mod required by the current adapter (DGM type 3) is as follows:
- Traces between pins 12, 13 and the switch resistors R24, R25 should be cut (or the resistors should be removed).
- Traces between pins 15, 16 and the unused EEPROM should be cut (or the eeprom removed).
- Wires should be routed between pins 15, 16 and the ungrounded switch nodes.
With internal pullups, switches should work as expected, and no extra flying wires to the adapter are needed.
![](http://funkyimg.com/i/2Cf8w.png)
Additional mods: The optotriac appears to have no current limiting resistor. This would put its operating current over 100mA. These inputs are only rated to about 60mA. Consider placing a resistor here.
youde 858DV4 (ZENY, etc)This board uses a single ADC input to sense both buttons in a manner which prohibits the use of button chords as required by the new firmware. The
original post describes the physical circuit layout and a potential mod to allow this ADC-sensing method to support chords. The current adapter (DGM type 2) uses a more conventional sensing method and requires the following modifications:
- Replace R21 with a jumper
- Remove EEPROM (or cut trace)
- Cut trace to isolate DN button from pin 11 node
- Add jumper from DN button to pin 18 or 19 (DGM adapter assumes 18)
This leaves 10k external pullup resistors in place for both buttons
![](http://funkyimg.com/i/2Cf8n.png)
Additional mods: TIP122 has no heat sink. At ~2.5W dissipation, this needs a heat sink to keep Tj within allowable limits.
ADAPTERS FOR ORPHAN BOARDSAs I've stated before, these layouts come with caveats. These are laid out with a mind toward hand etching/drilling (wider traces, no vias under parts, no attention paid to silkscreen, etc). They may require changes to meet what a board house would want; at the very least, you'd want to clean up the silkscreen layers if you have someone else print it. Also, any layout I throw together without being able to test it on the appropriate board is liable to have bugs in it. I offer these on the assumption that editing a complete but unverified project file would be more convenient than starting from scratch. Just do your due diligence and verify that it matches your actual board. If there's an error in the adapter or the board map from which I derived it, let me know.
I went ahead and shoehorned an ISP header on them since I'm probably the only person that doesn't want one.
The YOUDE adapter has a TQFP version, but there's really no point to using it unless those are the only parts you have. The extra vias would only make it more difficult to drill and assemble.
I tried to make sure the adapters clear obstacles on the board, but some things (transistors, small caps) might need to be laid down depending on how tall your headers are.
These are all Eagle project files.
YOUDE 858DV4 adapter
![](http://funkyimg.com/i/2Cfdp.png)
YH858D V7-V8 adapter
![](http://funkyimg.com/i/2Cfdn.png)
HD858D V1.0 (Hyiko) adapter
![](http://funkyimg.com/i/2Cfdj.png)