Just build your own, just finished building mine for $15(CAD). Runs off a CR2032 and has an on/off switch, excluding my crap soldering skills it turned out very nicely and works great for launching SX for me. Parts took 4 days to arrive in Canada vs the 1-2 months these Chinese things will take
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At first I tried to solder the boards like you did. But I allways had to touch the trinket board to get ground. Then I checked the page you linked to and found that this guy used the other ground soldering point. After I also changed the soldering points for ground it worked for me. Is it working for you flawless this way?