<![CDATA["Bottom" IO expander pinout]]>Hello everybody !

I've ordered M5Stack Basic kit and I'm preparing my project.

I'm not able to find any schematic / picture that describes the link between MBus to IO of the Bottom module

Following Schematic:
MBus have 30 pins with 20 GPIO
0_1524591940602_MBus.png

Following Bottom module picture:
Bottom module come with 46 pins with 30 IO...
0_1524592014196_Bottom pinout.jpg

I can figure out connection for 5V, 3V3, GND, RST, BAT but for the other ???

2 pins are named "DA". What does it mean ?
"R0"/"T0": RX/TX from UART 1 ?
"R2"/"T2": RX/TX from UART 2 ?
"2" means GPIO2 ? So what "G2" means ?

Anyone can help ? Do you have a document regarding that ?

Many thanks for your help,
Max

]]>https://community.m5stack.com/topic/188/bottom-io-expander-pinoutRSS for NodeWed, 29 Apr 2026 06:22:13 GMTTue, 24 Apr 2018 13:47:37 GMT60<![CDATA[Reply to "Bottom" IO expander pinout on Thu, 03 May 2018 16:29:06 GMT]]>Thanks you so much for your reply !
So, right now I'm understanding that I will have half IO than expected...

Thanks again, It helps me a lot
See you

]]>https://community.m5stack.com/post/938https://community.m5stack.com/post/938Thu, 03 May 2018 16:29:06 GMT<![CDATA[Reply to "Bottom" IO expander pinout on Tue, 24 Apr 2018 18:14:26 GMT]]>Names on the right side correspond to the GPIO numbers on the left and are connected together.

higher DA mean GPIO25
lower DA mean GPIO26

R0/T0 = GPIO3/GPIO1 -> uart0
R2/T2 = GPIO16/GPIO17 -> uart2

Similarly, bottom names applies to the gpio numbers at the top.

0_1524593532545_1524592015889-bottom-pinout.jpg

]]>https://community.m5stack.com/post/891https://community.m5stack.com/post/891Tue, 24 Apr 2018 18:14:26 GMT