diff --git a/doc/render.png b/doc/render.png index 5eeeef4..5d91761 100644 Binary files a/doc/render.png and b/doc/render.png differ diff --git a/readme.md b/readme.md index 1dacaba..2ea9f43 100644 --- a/readme.md +++ b/readme.md @@ -1,8 +1,6 @@ -**EEP! pin pitch on the BM1387 footprint is wrong!!** Don't make this board until this gets sorted. see issue [#5](https://github.com/skot/bitaxe/issues/5) - # The bitaxe ![](doc/assembled.png) -an experimental bitcoin mining machine. Uses 2x Bitmain BM1387 ASICs. Should be able to hash at around 130GH/s. Needs a lot of work! +an early-stage experimental bitcoin mining machine. Uses two Bitmain BM1387 ASICs. ## BM1387 ![bm1387 pic](doc/bm1387.png) @@ -12,7 +10,11 @@ an experimental bitcoin mining machine. Uses 2x Bitmain BM1387 ASICs. Should be - The BM1387 is available for around $1-2 each in low quantities from Aliexpress ## Current Status -- I have built 2 of these. +- I have built several v1 PCBs +- v1 has a problem with the pin pitch on the BM1387 footprint. + - it's very unlikely *all* of the pins were making contact. + - this has been corrected on v2, but not verified yet. Still waiting for PCBs to arrive. +- The voltages all appear to be right - I can't get any response over serial from the BM1387s yet. - The current comsumption does change like I would expect when I send a serial command to change the frequency. @@ -20,6 +22,9 @@ an experimental bitcoin mining machine. Uses 2x Bitmain BM1387 ASICs. Should be - [BM1387B from random AliExpress seller](https://www.aliexpress.com/item/2251832867687077.html). Do these work?? Who knows! - [40x40mm heatsink and 5V fan](https://www.aliexpress.com/item/2251832861666365.html) from a random AliExpress seller. At least half of these arrived broken in some way. But they are cheap and the working ones do keep the BM1387's nice and cool when used with some thermal compound. - The serial port is 1.8V. The [FTDI TTL-232RG-VREG1V8-WE](https://www.digikey.com/en/products/detail/ftdi,-future-technology-devices-international-ltd/TTL-232RG-VREG1V8-WE/2441359) USB adapter does the trick, although it's pretty expensive. +- [jim.sh Micro1v8 FT230X](https://www.amazon.com/dp/B076B9YRMP) adapters also work. +- Neither the FTDI cable or the jim.sh adapter breakout any of the CBUS pins that could be used for the reset line. + - for that I'm going to try the [UMFT231XE-01](https://www.digikey.com/en/products/detail/ftdi-future-technology-devices-international-ltd/UMFT231XE-01/4487117) breakout board. - [KiCad 6](https://www.kicad.org) design files - All of the parts on the board are listed in the KiCad BOM @@ -31,14 +36,14 @@ Check my [BM1387 Scripts](https://github.com/skot/bm1387_scripts)! | Pin Name | Description | | ----------- | ----------- | -| VIN | ASIC VIN - powers both ASICs in series. Should be around 1.6V for 0.8V at each ASIC. Will need at least 3A, maybe more! This needs more experimentation. | +| VIN | ASIC VIN - powers both ASICs in series. Should be around 0.9V for 0.450V at each ASIC. Will need at least 3A, maybe more! This needs more experimentation. | | +5V | 5V input gets regulated to 1.8V and 0.8V for the BM1387. Also 5V for Fan output. Not much current required. | | +5V (Fan) | 5V output for fan | | SPD (Fan) | Speed input from fan. Doesn't currently go anywhere | | 1V8 | 1.8V output. regulated from 5V. Use as a IO reference, or leave unconnected. | | RXI | 1.8V Serial input | | TXO | 1.8V Serial output | -| RST | Inverted reset pin to the first BM1387. Unsure what to use this for. | +| RST | Inverted reset pin to the first BM1387. Unsure how necessary this is. | | GND | Common ground | ## Goals @@ -46,4 +51,4 @@ Check my [BM1387 Scripts](https://github.com/skot/bm1387_scripts)! - Connect up the BM1387 internal temperature to the onboard microcontroller. - Connect up the fan speed sensor to the onboard microcontroller. - Develop some software in Rust to getblocktemplate from a bitcoin node and communicate work to a fleet of bitaxes. -- add an onboard power sensor +- add an onboard power sensor so we can set the hashrate (ASIC requency) and therefore current to extract maximum power from a solar panel.