Cisco Meraki MR16

This device has one Gigabit Ethernet port with PoE capability.


 * On OpenWRT Wiki
 * CPU: Atheros AR7161 @680MHz
 * Wireless: Atheros AR9223 2T2R 802.11bgn
 * Wireless: Atheros AR9220 2T2R 802.11an
 * Ethernet ports: Atheros AR8021-BL1E 1x GbE

Default settings are per the FCC manual.


 * Notes about RF chains, from a quick conversation, 2020-07-20
 * Yeah, I took a multimeter and looked for contact points [to poke around at the RF chains on the board and see what's attached to what by default.]
 * There are plenty of via's for electrically connecting certain parts of the folded antennas with the input and output chains of each chip
 * each chip has 4 chains -- 2 in, 2 out
 * those 4 chains get multiplexed into [many outputs].
 * there are two PIF antennas on the board for each radio for early testing (the 5GHz ones are hidden in the top and bottom corners of the [rightmost partition of the] the radio shield [where the 5GHz AR9220 lives], the 2.4GHz radio has one antenna peeking out near the top [left] and the other is near the bottom hidden beneath the [leftmost partition of the] shield)
 * there's a pad near the radio chip to electrically attach it to the PIF antennas, but they are not connected
 * I was able to trace the center (hot) contact of each of each UFL antenna back to both radio chips
 * so they are hard-wired to the radios. In addition, thankfully I was able to verify that they don't connect to the antennas in any other way. They were planning to and in fact you could remove the U.FLs if you wanted to and just solder on some zero-ohm resistors
 * basically most of the resistors and capacitors under and around the radio chips are for antenna development, and most are not needed
 * there are plenty of blank solder pads -- copper spots -- and some solder pads that have copper. All of those are 'switches' that you can add 0-ohm resistors to to active different antennas onboard but right now the chains end in U.FLs
 * One way to improve radio performance [by giving the 2.4 and 5GHz chains different physical fronends] would be to use a handful of 0-Ohm resistors and 4 U.FL headers and reroute the radios separately to separate antennas. There are pads for 2.4 and 5GHz U.FL pads but no headers for them.
 * back in Mar 2018 or 2019 I remember [Tomesh] did a thing where you tested long-range Merakis with that 5GHz directional anntenna [the Librerouter prototype antenna]. You attached it I think to the U.FL headers. that worked OK right? [a 100M test was done under OpenWrt, 5GHz 11n HT40, resulting in ~100Mbps transmission rates]
 * .... but I was worrying that like certain types of TP-LINK routers whether there was an electronic multiplexer for turning on / off the radio amplifier chains
 * turns out there's not. it's all soldered on [in the MR16].