00:00Everybody hits it.
00:01You solder on a second sensor, add a third, and suddenly the whole bus goes quiet because two devices are
00:07answering to the same I2C address.
00:09I pulled up the best sellers for fix I2C address conflicts with these multiplexers, and these little TCA9548A boards are
00:17genuinely the fix.
00:19Here's what I found.
00:21First up, the CJMCU9548TCA9548A128 breakout, and the standout here is the bundle, you get 5-10 boards in the pack.
00:30One multiplexer solves one address clash.
00:33But if you're running a robot with a pile of identical IMUs, you need several, and at $468 for the
00:39lot, the per-board cost drops to pennies.
00:42Breakout headers are pre-soldered, pins are labeled, and it just works on 3.3 or 5V.
00:48If you only need one, this is overkill, but for a full build it's the best value in the group.
00:54Next, this TCA9548A module at $267, the cheapest real module on the list, and it's the one that explicitly advertises
01:02PC bus and SM bus compatibility.
01:05That matters more than it sounds.
01:07SM bus has bus clear and timeout rules that plain I2C doesn't, so if you're bridging to a Raspberry Pi
01:13hat, a sensor board, or anything pulling from a PC's management bus,
01:17this is the one that behaves.
01:19The silicon is identical to the expensive boards, you're just not paying for a fancy silkscreen.
01:25Third is this a start-in TCA9548A channel board with Reset, 356.
01:31The Reset pin is the feature worth talking about, because most no-name clones bury it or leave it unconnected.
01:38When a slave holds SDA low after a power glitch, the whole bus locks up, and pulling Reset on the
01:43mux is how you kick it loose and get talking again.
01:45There are also address select jumpers on the back, so you can chain up to 8 muxes and address a
01:51full 64 devices.
01:53Solid choice if you work with flaky sensors.
01:56Now the budget pick, this TCA9548A 128 board for Arduino at $1.23.
02:03That is stupid cheap, and for the money it's genuinely hard to beat.
02:08The TCA9548A chip itself runs from 1.8 to 5.5 volts, and this board breaks out all 8 downstream
02:14channels with clearly labeled headers.
02:17Just check two things before you buy, make sure your pull-up resistors match your bus voltage, and confirm the
02:22address select solder pads are actually connected,
02:25because some of these ship with the A0 to A2 pads pre-bridged.
02:29Last one, this TCA9548A extender board with Reset at 383, and this is the one I'd actually recommend for a
02:36mixed-voltage setup.
02:37It calls out Arduino, Raspberry Pi, ESP32, and STM32 explicitly, and the logic levels are handled properly,
02:45so you can run a 3.3-volt Pi and a 5-volt sensor on the same bus without frying
02:49anything.
02:50It's also built as an extender, so you can daisy-chain muxes down a long sensor line.
02:56The reset pin is exposed, address selection is on jumpers, it's the most complete board here.
03:02Links for all five are in the description, and there's a pin-out diagram there too if you want to
03:07skip the datasheet.
03:08If this saved you from a two-day debugging spiral, hit like, and subscribe, I'm doing more I2C and sensor
03:14wiring breakdowns soon.
03:15DYNTHzero
03:15I'll experience
03:16By up we'll keep it
