Raspberry Pi 4 with Mesa 7c81
The images show a Raspberry Pi 4 mounted on to 7C81, a home made 40pin jumper cable and a DIN rail mount made up from the following Phoenix Contact products purchased from RS parts:
I will provide more photos once I have 7C81 + 7i85S mounted in the switchboard.
Its nice to have those part numbers. Can you clarify that the base 804-7420 comes in 1 metre long lengths?
rodw wrote: I wonder if you could mount a PoE hat on top of that for the ultimate compact no wires setup?
Can you clarify that the base 804-7420 comes in 1 metre long lengths?
1) There is sufficient space for a PoE hat, but I'm not sure that it's needed as the 40pin jumper provides the Pi with 5V power from the 7C81. The 3rd photo shows the 5V connector on the 7C81 which has good current carrying capacity and is more than adequate to power the Pi and the 7C81 + IO modules. I measured power consumption of my setup (7C81+7i85S) at around 1.2A with peaks of 1.5A, but that's without encoders and only one stepper drive connected.
I'm not sure that powering the 7C81 from the Pi via PoE hat is a good option, particularly if the 7C81 is jumpered to provide power to a few other IO modules, as all current for the 7C81+Anything IO modules would have to go through the 40pin jumper.
2) Yes, the UM108 rail comes in 1mt length and needs to be cut to size, but I'm sure it will come in handy for other projects. The hint for this came from page 1 of the 7C81 manual: ".. mounts in standard 107mm DIN rail channels". You can also find the UM 107 profile on AliExpress, but shipping from China is an issue at the moment.
I found the listing and saw the end caps were only $1.40 and then the backing was $56 and I nearly had a heart attack...
helioz2000 wrote: You can also find the UM 107 profile on AliExpress, but shipping from China is an issue at the moment.
Tell me about it. Today's job is to get 100kg of custom made parts out of China. The freight price is very keen...
cakeslob wrote: that looks pretty clean in the din rain mount. can you post a more in detail shot of your stand offs on the ribbon cable side? I have been curious as to how others do theirs
Ah yes, that part is bit tricky. It's actually not a full stand off, just a plastic M3 bolt with nuts, took a little bit of effort to get that arrangement into position. It's now installed on a gear tray, so no longer that easy to see .... I will try and take some photos for you tonight.
Here is the detail you requested:
cakeslob wrote: .... can you post a more in detail shot of your stand offs on the ribbon cable side?
The bolt coming up from the underside is tightened with the clear nut against the top of the 40 pin connector, a second [black] nut locks the clear nut into place and provides the correct height to match up with the standoffs on the other side. It tends to want to slide off the side of the connector until the pi keeps the two bolts at the correct spacing.