I like the friction type, so next time I would like to add a front derailleur to make a front and rear friction type electric bar end shifter. In that case, I would like to program the front derailleur with automatic trim. It moves linearly during operation and automatically trims after 1 second.
Exactly what was gained here?
Fun! And knowledge! 
improved riding skill from having to take a hand off the bars to shift.
Really?? That’s the best reason? You can’t take a hand off the bars without electric downtube shifting?
BTW, I am not clear on how that improves riding skill but if you believe it does, go for it.
I was joking.
I made one that shifts gears just by pressing a switch button, but the analog one was more fun to operate!
Your ingenuity and imagination are really impressive…Shimano should hire you so they can revamp the entire Di2 user experience.
Good stuff!!
This shift lever is based on the MAVIC ZAP professional team model, which is the pioneer of electric shifters.
I saw that…it was a nice touch. 
The really good thing that Mavic did with Zap and Mektronic is that they re-thought how the rider can interface with the shifting. Shimano basically just took the STI process and made it electronic. IMO, that was a big missed opportunity.
Did you see a switch dedicated to the professional team?
The design of Mektronic is eccentric and amazing. It wasn’t good for the management of the company.
That’s really great job. Well done.
Do you have any git repo / github or gitlab account where we could see the details of your design?
I wish e-shifting from the big manufacturers was open source. As customers we shouldn’t accept buying tech we can’t study, understand, repare or modify.
I myself wanted to build a kind of opensource homemade device similar to the archer d1x out of an arduino to convert my sram force 1 gravel transmission to 13sp cassettes.
I was thinking a stepper motor would make more sense as a servo surely would drain a battery very quickly right?
I haven’t posted on github.
Stepper motors may be better than servo motors. But what matters to me is the easiest way to make it with DIY.
