I2C relay boards.

[David Lesher]

I have need for a 8-16 channel I2C in, relay out expansion board.
We're now using:
<https://www.ereshop.com/shop/free/I2C-RL8xxM_SHEET.pdf>
but the shipping is insane.

So I'm seeking an alternative supplier. I figure one approach is
to find a forum where Arduino users hang out, and ask there.

Any suggestions for board suppliers or forums?
--
A host is a host from coast to coast.................wb8foz@nrk.com
& no one will talk to a host that's close..........................
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

 

[Michael A Terrell]

David Lesher wrote:

I have need for a 8-16 channel I2C in, relay out expansion board.
We're now using:
https://www.ereshop.com/shop/free/I2C-RL8xxM_SHEET.pdf
but the shipping is insane.

So I'm seeking an alternative supplier. I figure one approach is
to find a forum where Arduino users hang out, and ask there.

Any suggestions for board suppliers or forums?

PCF8574-I2C-Bidirectional-I-O-Expander-Relay-Control-SmartHome-Ardiuno-Raspberry

https://www.ebay.com/itm/282692860765 US $2.90

Used with:

/8-Eight-Channel-5V-Relay-Module-Board-with-Optocoupler-Power-Supply-PIC-ARM

https://www.ebay.com/itm/322834065204 US $6.39


gives you eight relays for $9.29 plus some wires between the modules.

 

[David Lesher]

Michael A Terrell <mike.terrell@earthlink.net> writes:

PCF8574-I2C-Bidirectional-I-O-Expander-Relay-Control-SmartHome-Ardiuno-Raspberry

https://www.ebay.com/itm/282692860765 US $2.90

Used with:

/8-Eight-Channel-5V-Relay-Module-Board-with-Optocoupler-Power-Supply-PIC-ARM

https://www.ebay.com/itm/322834065204 US $6.39

gives you eight relays for $9.29 plus some wires between the modules.

Seen many versions of that. Want an integrated board w/relays. Found several
but all thus far are international $hipping.


--
A host is a host from coast to coast.................wb8foz@nrk.com
& no one will talk to a host that's close..........................
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

 

[Michael A Terrell]

David Lesher wrote:

Michael A Terrell <mike.terrell@earthlink.net> writes:


PCF8574-I2C-Bidirectional-I-O-Expander-Relay-Control-SmartHome-Ardiuno-Raspberry

https://www.ebay.com/itm/282692860765 US $2.90

Used with:

/8-Eight-Channel-5V-Relay-Module-Board-with-Optocoupler-Power-Supply-PIC-ARM

https://www.ebay.com/itm/322834065204 US $6.39

gives you eight relays for $9.29 plus some wires between the modules.

Seen many versions of that. Want an integrated board w/relays. Found
several but all thus far are international $hipping.

OK, make your own. A schematic of that board is online.

 

[rickman]

David Lesher wrote on 10/26/2017 11:35 AM:

Michael A Terrell <mike.terrell@earthlink.net> writes:


PCF8574-I2C-Bidirectional-I-O-Expander-Relay-Control-SmartHome-Ardiuno-Raspberry

https://www.ebay.com/itm/282692860765 US $2.90

Used with:

/8-Eight-Channel-5V-Relay-Module-Board-with-Optocoupler-Power-Supply-PIC-ARM

https://www.ebay.com/itm/322834065204 US $6.39

gives you eight relays for $9.29 plus some wires between the modules.

Seen many versions of that. Want an integrated board w/relays. Found several
but all thus far are international $hipping.

I don't follow what is so bad about international shipping? The typical
vendor of inexpensive boards is in Asia and ships for free. I found two on
eBay that sell 8 channel I2C relay boards with a different form factor for
$80 or $90 in the US. Where are you?

--

Rick C

Viewed the eclipse at Wintercrest Farms,
on the centerline of totality since 1998

 

[David Lesher]

Michael A Terrell <mike.terrell@earthlink.net> writes:

OK, make your own. A schematic of that board is online.

Worst option. Avoiding manufacturing anything; just exponential time-sink.
Would prefer the integrated board but may end up with split approach.
--
A host is a host from coast to coast.................wb8foz@nrk.com
& no one will talk to a host that's close..........................
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

 

[Michael A Terrell]

David Lesher wrote:

Michael A Terrell <mike.terrell@earthlink.net> writes:



OK, make your own. A schematic of that board is online.


Worst option. Avoiding manufacturing anything; just exponential time-sink.
Would prefer the integrated board but may end up with split approach.

The split configuration would make it easier to repair, and the
control boards can be plugged end to end. You can eliminate the jumpers
on the headers with a drop of solder on the underside of the boards.

If a relay board or controller board fails, it will be much cheaper
to repair. You can buy ready made 40 conductor cables with single Dupont
contacts on Ebay to harness them together. I remove the single contact
shells and replace them with a single, with the proper number of
positions. That way, my projects look a lot neater than the typical wad
of individual wires.

I may use a pair of these boards in a custom, multiple iron
soldering station that I'm building.

 

[David Lesher]

rickman <gnuarm@gmail.com> writes:

I don't follow what is so bad about international shipping? The typical
vendor of inexpensive boards is in Asia and ships for free. I found two on
eBay that sell 8 channel I2C relay boards with a different form factor for
$80 or $90 in the US. Where are you?

The best boards we've found are:
<https://www.ereshop.com/shop/index.php?main_page=product_info&cPath=143_178&products_id=767>
as they come with 24V relays, an advantage.

But price it out:

$35 board, $31 of shipping.

And form factor does matter to us.

--
A host is a host from coast to coast.................wb8foz@nrk.com
& no one will talk to a host that's close..........................
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

 

[David Lesher]

Michael A Terrell <mike.terrell@earthlink.net> writes:

The split configuration would make it easier to repair, and the
control boards can be plugged end to end. You can eliminate the jumpers
on the headers with a drop of solder on the underside of the boards.

If a relay board or controller board fails, it will be much cheaper
to repair. You can buy ready made 40 conductor cables with single Dupont
contacts on Ebay to harness them together. I remove the single contact
shells and replace them with a single, with the proper number of
positions. That way, my projects look a lot neater than the typical wad
of individual wires.

40?

I need some 10 position one-row headers but will likely use
two-row 20's and ignore the other. I do plan to plug them end
to end but will need to hold them. Thinking a slotted /______\
piece of soft plastic that in turn is mounted to the DIN rail.

--
A host is a host from coast to coast.................wb8foz@nrk.com
& no one will talk to a host that's close..........................
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

 

[Michael A Terrell]

David Lesher wrote:

Michael A Terrell <mike.terrell@earthlink.net> writes:


The split configuration would make it easier to repair, and the
control boards can be plugged end to end. You can eliminate the jumpers
on the headers with a drop of solder on the underside of the boards.

If a relay board or controller board fails, it will be much cheaper
to repair. You can buy ready made 40 conductor cables with single Dupont
contacts on Ebay to harness them together. I remove the single contact
shells and replace them with a single, with the proper number of
positions. That way, my projects look a lot neater than the typical wad
of individual wires.

40?

I need some 10 position one-row headers but will likely use
two-row 20's and ignore the other. I do plan to plug them end
to end but will need to hold them. Thinking a slotted /______\
piece of soft plastic that in turn is mounted to the DIN rail.

Yes, ribbon cable. Peel off as many conductors as you need. The color
code repeats every ten conductors.

T1-3X-40pcs-20cm-Male-To-Male-Female-Dupont-Wire-Jumper-Cable-Arduino-Breadboard

https://www.ebay.com/itm/231708399395

 

[David Lesher]

Michael A Terrell <mike.terrell@earthlink.net> writes:

I need some 10 position one-row headers but will likely use
two-row 20's and ignore the other. I do plan to plug them end
to end but will need to hold them. Thinking a slotted /______\
piece of soft plastic that in turn is mounted to the DIN rail.

Yes, ribbon cable. Peel off as many conductors as you need. The color
code repeats every ten conductors.

T1-3X-40pcs-20cm-Male-To-Male-Female-Dupont-Wire-Jumper-Cable-Arduino-Breadboard

https://www.ebay.com/itm/231708399395

I'd rather use an IDC connector that matches the headers; less
chance something gets loose/ is misconnected.
--
A host is a host from coast to coast.................wb8foz@nrk.com
& no one will talk to a host that's close..........................
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

 

[rickman]

David Lesher wrote on 10/28/2017 2:23 PM:

Michael A Terrell <mike.terrell@earthlink.net> writes:

I need some 10 position one-row headers but will likely use
two-row 20's and ignore the other. I do plan to plug them end
to end but will need to hold them. Thinking a slotted /______\
piece of soft plastic that in turn is mounted to the DIN rail.

Yes, ribbon cable. Peel off as many conductors as you need. The color
code repeats every ten conductors.

T1-3X-40pcs-20cm-Male-To-Male-Female-Dupont-Wire-Jumper-Cable-Arduino-Breadboard

https://www.ebay.com/itm/231708399395


I'd rather use an IDC connector that matches the headers; less
chance something gets loose/ is misconnected.

The IDC connector is a solid block and fixed size. The "Dupont" cables can
be used in any width or as individual wires. The connectors on the end
aren't tied on with string. They work great. You can get them in either
male or female on both ends and in any combination. Very flexible indeed.

--

Rick C

Viewed the eclipse at Wintercrest Farms,
on the centerline of totality since 1998

 

[David Lesher]

rickman <gnuarm@gmail.com> writes:

The IDC connector is a solid block and fixed size. The "Dupont" cables can
be used in any width or as individual wires. The connectors on the end
aren't tied on with string. They work great. You can get them in either
male or female on both ends and in any combination. Very flexible indeed.

Yes, I see. But they are fixed length. With ribbon+IDC, I can make the cables
the correct length.


--
A host is a host from coast to coast.................wb8foz@nrk.com
& no one will talk to a host that's close..........................
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

 

[rickman]

David Lesher wrote on 10/28/2017 2:38 PM:

rickman <gnuarm@gmail.com> writes:


The IDC connector is a solid block and fixed size. The "Dupont" cables can
be used in any width or as individual wires. The connectors on the end
aren't tied on with string. They work great. You can get them in either
male or female on both ends and in any combination. Very flexible indeed.

Yes, I see. But they are fixed length. With ribbon+IDC, I can make the cables
the correct length.

They are available in many lengths, mostly multiples of 5 cm. Works for me.

--

Rick C

Viewed the eclipse at Wintercrest Farms,
on the centerline of totality since 1998

 

[Michael A Terrell]

David Lesher wrote:

Michael A Terrell <mike.terrell@earthlink.net> writes:

I need some 10 position one-row headers but will likely use
two-row 20's and ignore the other. I do plan to plug them end
to end but will need to hold them. Thinking a slotted /______\
piece of soft plastic that in turn is mounted to the DIN rail.

Yes, ribbon cable. Peel off as many conductors as you need. The color
code repeats every ten conductors.

T1-3X-40pcs-20cm-Male-To-Male-Female-Dupont-Wire-Jumper-Cable-Arduino-Breadboard

https://www.ebay.com/itm/231708399395


I'd rather use an IDC connector that matches the headers; less
chance something gets loose/ is misconnected.

Really? Have you ever used the Dupont connectors? They are reliable,
and inexpensive.

I've used thousands of them, along with IDC. Only a keyed header and
a keyed IDC connector will prevent misconnecting a cable. The color
coded wire that I mentioned makes it easy, since they follow the
standard color code. Start with black for pin one. Consider it the
stripe on typical ribbon cable.

 

[rickman]

Michael A Terrell wrote on 10/28/2017 3:27 PM:

David Lesher wrote:
Michael A Terrell <mike.terrell@earthlink.net> writes:

I need some 10 position one-row headers but will likely use
two-row 20's and ignore the other. I do plan to plug them end
to end but will need to hold them. Thinking a slotted /______\
piece of soft plastic that in turn is mounted to the DIN rail.

Yes, ribbon cable. Peel off as many conductors as you need. The color
code repeats every ten conductors.

T1-3X-40pcs-20cm-Male-To-Male-Female-Dupont-Wire-Jumper-Cable-Arduino-Breadboard


https://www.ebay.com/itm/231708399395


I'd rather use an IDC connector that matches the headers; less
chance something gets loose/ is misconnected.


Really? Have you ever used the Dupont connectors? They are reliable, and
inexpensive.

I've used thousands of them, along with IDC. Only a keyed header and a
keyed IDC connector will prevent misconnecting a cable. The color coded wire
that I mentioned makes it easy, since they follow the standard color code.
Start with black for pin one. Consider it the stripe on typical ribbon cable.

Shouldn't black be pin zero?

--

Rick C

Viewed the eclipse at Wintercrest Farms,
on the centerline of totality since 1998

 

[Michael A Terrell]

rickman wrote:

Shouldn't black be pin zero?

If you can find a pin zero, you can use it.