WIZ820io & Micro SD Card Adaptor connections

[Jef Patat]

Hi all,

I have a project in mind in which I would like to use 2 times RS232 and ehternet. Teensy 3.2 looks perfect, the Wiz820io looks perfect and the adapterboard offers additional SD which I might use as well.

It's however not clear to me from the description if I can use 2 times RS232 (HW wise, not SW wise) together with the Wiz820 and SD. Serial1 (pin 0/1) should be ok, Serial 2 (pin 9/10) can not be used, but what about Serial 3? There is some description about pin 8 and jumper pads left side but I don't understand what that means, could anyone explain?

thank you and happy new year to all,
Jef

 

[Jef Patat]

I should also mention that I don't need the low power features because the device will be powered all the time. Can I just not connect pin 8 to the adapter board and use it for serial communication?

 

[PaulStoffregen]

but what about Serial 3? There is some description about pin 8 and jumper pads left side but I don't understand what that means, could anyone explain?

Yes, you can use Serial3.

Pin 8 routes to an unconnected pad. If you cut a trace and soldered to that pad, you could use pin 8 to control the WIZ820io powerdown feature. Don't solder to that pad! Just leave it as-is, so the WIZ820io doesn't power down and pin 8 remains unconnected to anything on the WIZ820io.

If you *really* need Serial2, there's a pair of alternate pins on the bottom side. That requires connecting to the bottom side, and a code hack to switch Serial2 to those other pins. Pretty inconvenient, but if you need it, the option is there.

 

[Jef Patat]

Thanks for the info Paul! Let's buy some new toys

Edit: one additional question: is the MCP1825 regulator strong enough to feed SD and the wiz820io simultaneously? Am I correct in assuming that the teensy has it's own supply that and the MCP1825 is only for SD/Wiz820io?