Super I/O for next kit, getting the most out of a single I/O pin

[blueroomelectronics]

I'd appreciate your review / opinions on the following schematic. The Ladybug (Ethernet, RS232, LCD & I/O web server) PCB will allow at build time multiple ways of configuring the I/O. Here's the concept.
**broken link removed**
The I/O section can be assembled in many ways on the new Ladybug LAN I/O kit

 

[Leftyretro]

I'd appreciate your review / opinions on the following schematic. The Ladybug (Ethernet, RS232, LCD & I/O web server) PCB will allow at build time multiple ways of configuring the I/O. Here's the concept.
**broken link removed**
The I/O section can be assembled in many ways on the new Ladybug LAN I/O kit

I like the concept a lot. Does that mean the PCB layout will have existing space and pads for all the various I/O components shown (relay, opto, resistors, etc) ?

My only caution would be how hard it might be to document the assembly or user manual for newcomers to properly implement the correct I/O usage desired, or even knowing which option they need for their application.

Lefty

 

[blueroomelectronics]

Thanks for the comment, all eight I/O ports will have identical pad layout and a pictorial. I may add an LED indicator option for some of the configurations like Relay & opto. Not shown is the snubber circuit option for the relays.
PS there are also two dedicated NO/COM/NC relays for a total of 10 relays if that's what you need.

 

[3v0]

The Ladybug is an Ethernet Enabled Swiss Army Knife. I like it.

 

[kchriste]

The silkscreen for this could be interesting. Rather than trying to fit all the possible component placements on the silkscreen, maybe you could show the solder side traces on the silkscreen and/or number the holes.

 

[blueroomelectronics]

The Ladybug is an Ethernet Enabled Swiss Army Knife. I like it.

Something like that.
Ladybug LAN

• 18F4620 @ 9.8304MHz * 4 (PLL)
• ENC28J60 Ethernet IC @ 25MHz
• 25LC1024 EEPROM
• RS485
• 8 Super I/O (6 Analog, 2 CCP) RA0-5, RC1,2
• 2 Relays RB1,2 Omron 2A @ 125VAC (ideal for HVAC)
• LCD connector or I/O expansion + 4 pushbuttons
• ICD connector
• large 30 screw terminal connector
• 9-16VAC/DC

Working prototype too, based on a modified Microchip stack (see the links section on my site)

 

[blueroomelectronics]

The silkscreen for this could be interesting. Rather than trying to fit all the possible component placements on the silkscreen, maybe you could show the solder side traces on the silkscreen and/or number the holes.

Not a bad idea, nice thing is I only have to do it once
Because it'll either be simple or very complex I'm leaving the status indicator LEDs off till I see what it looks like.

 

[blueroomelectronics]

I've removed the opto isolation for the I/O, thinking about an AC zero cross option.
Here's an early version of the Ladybugs main controller (tested)
**broken link removed**

 

[blueroomelectronics]

Well just an update. Here's the first of the Opto In/Out PCB artwork.
Kind of a fun layout, buffered LED indicator. Note the unusual six pin 4N36 mounts differently depending on how you build it.
It can be built as an

• Opto isolated OUTPUT
• Opto isolated INPUT
• Direct I/O with optional pullup (jumper across the opto)

**broken link removed**
Opto I/O (Ladybug 3x)

And here's the Super I/O

• 2A @ 24VDC Relay output with optional LED and clamp TVa1
• Direct TTL input with optional pullup/pulldown
• Analog input
• Direct output TTL

**broken link removed**
Super I/O (Ladybug 8x) relays may be 5V or 9V types

 

[justDIY]

awesome artwork as usual Bill!

sometimes for me drawing these layouts is more fun then what the gizmo actually does

 

[blueroomelectronics]

I'm not sure about the Opto silkscreen, not sure how to make it much clearer. I suppose 3D drawings will help.

 

[justDIY]

hows about boxes on the silkscreen, sectioning off specific areas, and then in addition to 'generic' part names, have a mention of a diagram number in the box. then you can draw up a separate diagrams the builder can refer to, showing different configurations (in 3d if you like)

 

[blueroomelectronics]

Putting too much info on the PCB makes it very cluttered, you've also got to keep the line thickness around 2mm or it won't print right.

I've also got to find a NEMA box for it. (Like your homes fuse box)

 

[Gayan Soyza]

I've removed the opto isolation for the I/O, thinking about an AC zero cross option.

To detect Zero cross I usually connect it to an external interrupt pin.In 18F4620 there are three channels available.

 

[SPDCHK]

Something like that.
Ladybug LAN

• 18F4620 @ 9.8304MHz * 4 (PLL)
• ENC28J60 Ethernet IC @ 25MHz
• 25LC1024 EEPROM
• RS485
• 8 Super I/O (6 Analog, 2 CCP) RA0-5, RC1,2
• 2 Relays RB1,2 Omron 2A @ 125VAC (ideal for HVAC)
• LCD connector or I/O expansion + 4
• ICD connector
• large 30 screw terminal connector
• 9-16VAC/DC

Working prototype too, based on a modified Microchip stack (see the links section on my site)

Most of the IO and connections you mention above is typical for industrial use as well.

Why then not also cater for a 24V power supply? I'm sure that in my C&I (Control & Instrumentation) practice I would use a small module like this for some remote plant.

 

[blueroomelectronics]

I've used INT0 for the ENC28J60 and the other two are OPTO. I'll leave some open test points for user mods.

 

[Gayan Soyza]

I have been using 1Mohm approach to detect Zero cross in many times without any problem.But for a kit it need some isolation.

 

[blueroomelectronics]

I've dropped the zero crossing and added XBEE support.
Here's the current Ladybug schematic. The part numbers need to be fixed but it's complete as far as I can tell.
**broken link removed**

 

[ThiSel]

Use of buffers

Hi Bill,

I am trying out my own circuit for ethernet using ENC28J60.

I have to interface with other I2C devices; I cant understand the part with the buffer, where can I read up about the I2C bus (and the use of buffer with them).

Thank you!

Regards,
Thiruselvam

 

[blueroomelectronics]

The ENC28J60 is high speed SPI not I2C, it also has an 8K buffer built in.