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Topic: Arduino 101 Serial to ESP8266 (Read 203 times) previous topic - next topic

Hokahonay

Nov 18, 2018, 06:24 pm Last Edit: Nov 19, 2018, 01:09 pm by Hokahonay
hi
i bought a Genuino 101 at the very start of its story.
i am using 101 with ESP8266 serial to serial for communication.

i have set up initially for 101 to send to ESP

the comms almost works, i say almost because if i use 2400 bauds i get good regular communication
if i use 4800 bauds comms becomes a bit flakey and above that doesn't work.

looking at the serial with an oscilloscope at 2400 bauds there is a good wave with clean edges
at 4800 bauds the wave appears to start running out of sink current i.e. the falling edge starts to look more triangular than square

i see from the forum that initially digital pin source / sink current was specified as being 4ma and later upgraded to 20ma.

as i have an early board (i had to pre order when they first came out) does this mean that my board will be the 4ma source / sink or 20mA

i am using 4K7 pullup resistors on the ESP (RX) end of the line so i would not expect .7ma not to be too much unless this is the case but it looks as though it might be that my board is 4ma

can anyone please tell me if all boards are 20ma or are some 4ma

thanks

Dave

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