Quote from: kingcolex on March 23, 2015, 03:15:39 PM

Did I miss a post? I never saw that he said he was putting off the 1.3th upgrade kit style for stick miners or to make money to produce others?

We're not putting off the TypeZero, if at all possible. But the USB stick miner is basically a tangible dev milestone between having nothing at all and having the full product. Since there's not a lot of extension required between having a one-chip miner and a two-chip miner, and between a two-chip miner and an eighteen-chip miner, and since our one-chip test bench will already be 80-90% of a working USB stick miner, there's no real reason not to go the extra 10-20% to make the complete product if 1) many people want them and 2) it's an affordable learning tool to introduce noobs to bitcoin.
We haven't stated outright that we'd be using sales profits from the stickminer to fund the TypeZero, but honestly that's what's going to happen. We got a bucket to put money in from whatever sales we have of whatever products and services, and then we pull money out of that bucket to stay in business. Profits won't be much from stickminers; selling 1000 sticks probably won't make enough profit to fund 50 of the TypeZero boards, but it's a start.

Once we have our breakout boards in hand and working, I'll complete a PCB design for stick miners. That'll be sent off to a board house for proto PCBs and while waiting for them, I'll work on TypeZero layouts. Then we'll assemble and sell stick miners while completing TypeZero layouts and getting prototype boards for it. Then once that's tested and working (and verified by some trusted hardware guys, probably talk to Philipma and MrTeal to start) we'll look into taking in money for a full manufacturing batch - contingent on chip availability from Bitmain, which it looks like might have a couple months' lead time. Which ain't exactly the best thing but if we can get everything else ready early and then the final step is dropping the BM1384s on the boards, testing and shipping, shouldn't be the end of the world. But it's not great.

Quote from: RadekG on March 23, 2015, 03:34:20 PM

How far are you with testing heat dissipation? AFAIK most of the chips are made bottom dissipated, this is done because high power chips are usually soldered on heatpad, so heat transfer through solder balls (or pads) is better bottom. Don't know if BM1384 is this case. Also, this can be seen on A1 chips or older BM chips... Different situation is with big-die chips, they are upside-down with direct or indirect contact to heatsink.

I thought that string design needs bigger capacitors closer to Vcore pins to bypass transients caused by chips current draw variation.

I am nowhere with testing heat dissipation. All I know is, every existing BM1384 miner uses heatsinks on the chip tops. I'm assuming the manufacturer knows what it's doing, and since the S5 seems to have no problem drawing 10W per chip out the top (and supplemented by airflow over the board with the aid of the side panels) I'm gonna assume it works that way until I have the setup to do direct testing.

String design does need large capacitors to buffer current transients (and therefore voltage transients) at a node level, and the S5 does have smaller caps immediately tied to the VDD pads probably to compensate for trace and lead inductance and ESR of the node-level caps. Keeping a constant node voltage and current is a stiffer requirement for string designs than for parallel VRM designs.