1. I notice that at the bottom of Table 1 (RFM69HW Pinouts) on page 10 of the v1.3 HopeRF RFM69HW datasheet, it says that NC should "Connect to GND."
However,
2. I notice that the Moteino R4 with an RFM69HW does not do that. It does not appear to connect NC to anything at all. In fact, the NC Pin is not even soldered.
Which is correct?
There's a single NC pin and it is not connected to anything on the RFM69 board (W or HW). So no point in adding a pad for it if it has no meaningful purpose.
saves 0.01g of solder paste and 1 second of assembly time on every Moteino. It adds up, you know.
Quote from: OSBSS on April 27, 2016, 02:55:51 PM
saves 0.01g of solder paste and 1 second of assembly time on every Moteino. It adds up, you know.
It really does.
The module has 16pins. With the RFM69 library (using only DIO0) only a total of 8 pins require soldering. So does it make sense to solder all pins even if only half are used? No. Any problems with that? Not at all. If someone wants to solder another pin they are free to do it, in fact not having unused pins soldered makes it possible to connect those unused pins in whatever way one would want to.
Quote from: OSBSS on April 27, 2016, 02:55:51 PM
saves 0.01g of solder paste and 1 second of assembly time on every Moteino. It adds up, you know.
Actually, I think the size of the unnecessary pad would be the biggest factor in my mind in eliminating it. Routing realestate is very valuable.
However, the thing I would prefer with the Moteino RFM69 layout is that the second GND pad be connected. To me, with RF or high speed/current components, GNDs are sacred. If they're on the module, use them and, if there's a plane on both sides of the board, put vias to make a thorough connection between the planes at the module's pads.
Tom
Quote from: TomWS on April 27, 2016, 06:44:47 PM
However, the thing I would prefer with the Moteino RFM69 layout is that the second GND pad be connected. To me, with RF or high speed/current components, GNDs are sacred. If they're on the module, use them and, if there's a plane on both sides of the board, put vias to make a thorough connection between the planes at the module's pads.
Yes I can see the value in that, definitely something I will try to keep in mind, unless routing makes it impossible!
In fact for the LoRas and HCWs this is already implemented, all GND pads are used.