yes you need resistors on the 2 wires to the pi, example here: https://tutorials-raspberrypi.com/raspberry-pi-ultrasonic-sensor-hc-sr04/

JST-XH-2.54 2-Pin is the connector type,

here is a dev enviroment for you to program bittle https://ide.tinkergen.com/

there is codecraft which is a block based programmer for bittle,(would probly work with nybble too) https://ide.tinkergen.com/

for pi serial communication to need to set the i2c switch to the nyboard as the master NOT the pi. theres no code available yet for using i2c from pi

i been told i can have one as my birthday and Xmas present combined, i should get mine in January. so excited to learn how it works. from the looks of the info the Kickstarter backers should receive their cats over the next 2 months due to a few updates to the design.

from checking it looks like a standard JST-XH connector.

ah that sounds ok. one other thing, would it be possible to add a 4pin header (+v,gnd,io1,io2(digital io)) for the ultrasonic sensor?? as adding this port will make it perfect for use out the box with Nybble.

you have a similar rgb ultrasonic module fitted in a Nybble head in your collection. https://www.instagram.com/p/B2b8qL_n9ac/?utm_source=ig_web_button_share_sheet

if you re-added the i2c servo driver you would free up 12 pins for digital i/o for sensors, screens, leds, and capacitive touch.

oh well maybe next time. i hope a future v2 of the battery will have Qi wireless charge function as well as its current usb charge method

can you list or direct us to a list of all the pre-programed commands that can be sent please

how many digital I/O pins are there for connecting sensors? how accurate is the battery monitor? and is it easy to access? cant wait to try out the new board