That’s a good question… @stuart any reason why you used two different I/O expanders?
TCA9534A
Controls RGB LED, TFT display LED and AVR ISP reset line
TCA6408AQPWRQ1
Controls relay’s and external IO A/B/C/D/E
One is capable of running at 5v, but having 3.3v logic levels, the other is only used to provide I/O on the controller itself and only runs at 3.3v
@stuart
The PCA9538PW/Q900,118 seems to be a combination of both, offering the following features:
- Operating power supply voltage range of 2.3 V to 5.5 V (3.0 V to 5.5 V
for PCA9538PW/Q900) - 5 V tolerant I/Os
hmm… the PCA9554APW,118 is available for assembly now… It doesn’t have a reset and it has internal pullups on the I/O’s which will draw a little more power… I’m not sure if the reset is necessary?
Do I want to have the part pre assembled or self source the PCA9538 and solder it myself!! decisions, decisions…
After looking at it further… We would have to hook VDD to 3.3V. This would limit the external io connections to drive to 3.3V only. If those have to drive to 5V then a translator would be needed.
For me that’s fine. I don’t think I need them to be 5V? I think I’ll make it so with some population options, either part (the original or the PCA) can be used…
For Searching a replacement of the TCA6408AQPWRQ1take into account that this specific device has two separated supply circuits for IO and communication.
Allows Bidirectional Voltage-Level Translation and
GPIO Expansion Between 1.8-, 2.5-, and 3.3-V I2C Bus and P-Ports
In the past we had a wrong type on the controller that could only handle 3v3 on the IO side while it was connected to 5v.
fwiw,
my controller is running with these for 3m now:
PCA6408APW.118
PCA9534APWR
relays work, tft works, led works. Worth a check. Bought in Nov (iirc) from Mouser at reasonable prices. No need to edit code either.
cheers
V.
Both are out of stock
oops, sorry!
mind just checked ebay and at least PCA9534APWR is available for 3-4usd for a fivepack (but from China)
V.
Unless I"m missing something… Digikey has stock for PCA6408APW.118
and Newark has stock for both [PCA6408APW,118] and [PCA9534APWR]
PCA9554A should also work for PCA9534A… It just has internal pullups on the i/o’s and will
burn more power when pulled low…
I just received my JLCPCB order of the ESP32 Controller Board. It was missing a couple parts C3, C4 Tantalum Capacitors, the relays, as well the TCA9534A. I ordered off eBay from the UK the TCA9534A. Im praying they are legit. The company looked to have pretty good reviews. Here’s the link if anyone is interested. They are $5/GBP not exactly cheap but I figured I would try this before the Chinese fakes/empty box.
By the way does anyone have a good replacement for C3,C4 Tantalum Capacitors? The LCSC part number off the BOM doesn’t even come up with anything.
From a quick search on Mouser.com TAJA226K006RNJ looks like a suitable replacement option, and in stock!
Excellent, always appreciated your advice throughout this forum. The project is slowly coming together just waiting on a few more items to be ordered.
DON’T ORDER FROM HERE!!! THEY WERE WRONG VERSION OF CHIP.
Just received 4x TCA9534A, but they are SOIC-16 and must either be the DWR or DWT variant.
Just received the TCA9534A TSSOP16 from Lanka Electronics ( http://www.lankamicro.com) - Chip is working and doing its job! 
They were about $3,80 each, shipment via China Post EUB $7 and customs again about $7… It took about 5 weeks or so…
Silly question, i am trying to finish cellboards45 with attiny. By mistake I ordered instead of attiny1624 attiny 1614 because of error/mistake in BOM file
In BOM
on line
21 20MHz, 16kB Flash, 2kB SRAM, 256B EEPROM, SOIC-14 ATtiny1614-SS
Question:
is it possible to replace attiny1624 with 1614? What changes needs to be done in firmware or platformIO files?
I tried to flash provided hex file, upload was successfull, but module does not blink or anything, so i am bit confused (I have 50pcs…to make :))
As far as I have checked, 1614 has only 10bit ADC.1624 is not available for next 3 months…