So I had the VESC showing power, but not responding to the ST-link programmer. Last week, Jack borrowed some mosfets to build his own VESC, and I lent him my programmer and we took a quick look at mine. Nothing obviously wrong – the STM got power, but didn’t respond, so we left it at “not sure if board or dongle”.
At some point, Jack obviously got his own board running and tested my dongle. He messaged me with the good news that my $8 eBay dongle was just fine, so the ESC was probably … not. “Did you get 2 layer boards printed? Cos it’s a 4 layer design…”
Why yes, Jack, yes I did somehow order 2 layer boards for a 4 layer design. So those middle two layers of connections, probably important.I have re-ordered PCBs in *4* layers, for the latest design. I am slightly pleased that it’s (possibly) not my soldering that was the problem….
Having discovered Benjamin Vedder’s open source ESC ( http://vedder.se/2015/01/vesc-open-source-esc/ ), I’ve decided to build a couple over the summer. I ordered parts a while back, and after exams I finally have enough time to build it. So I wandered into the TAFE side of school to borrow a reflow oven from the techs. I’ve done a number of fiddly things in my time, but this was by far the fiddliest. Tiny things everywhere. This was my first time with reflow, and first time with stencils for the paste. Again, fiddly, but once the stencil is centred, so much less fiddly than other methods. I will get metal stencils next time, I think, but the mylar was ok for this job.
All present and correct on side 1. Didn’t get around to side 2 on Monday, but I did arrange a lot of tiny resistors.
On Monday, this was the fiddliest thing I had ever done:
That record lasted 2 whole days:
This is Benjamin Vedder’s ESC – http://vedder.se/2015/01/vesc-open-source-esc/. I haven’t programmed the STM yet, but I powered it up, and a little blue light came on and nothing caught fire. Sounds like a win!