@ Searing, not a dumb question.
This is probably a dumb question but I have not seen it addressed anyplace..
I don't suppose the bridge connector used on a mercury/saturn/jupiter/neptune board could be used as a bridge or at least modified as such?
again unlikely but just for clarity I figured I'd toss it out here..probably not one being a BBB to port board and other being PI to port board
and a 2nd newbie question...
I have read that the boards are the same between the say the previous BTC KNC boards *jupiter/neptune* etc ....but if that is true is it only
for the NOV such boards? and by the same I mean PHYSICALLY the same. I realize the FPGA chip I think it is has not be reverse engineered
thus no clone Titan Controllers
anyway just catching up on the stuff here beyond my expertise (which is much)
There is no 'bridge' board between a BBB and a kfc controller.
The BBB plugs directly into the BBB compatable connector on the controller.
The controller boards are the same for all the BTC products from kfc.
I use Oct. Saturn controllers on nepturds. No difference WITH the correct firmware.
Educated guess says this 'bridge' board you guys are referring to is just lining up the power and SPI pins of the R Pi to the pinouts of the BBB connector that is on the controller PCB. SPI is P1 pins 5&6 on a Pi and P9 19&20 on a BBB.
There is probably also a voltage regulator involved. And should be but probbly missing if they tried it and it worked logic level shifting circuitry.
The main difference between them(hoopiter vs. nepturd) is the program(spimux.rbf) that is loaded into the FPGA by the firmware.
The primary function of the FPGA is to take the multiplexed SPI signals from a Pi or BBB and de-multiplex it to correct seperate physical cube serial interfaces.
The software on the Pi or BBB sends all external cube communication over a single 'data' wire to the FPGA.
(there is also a clock wire, SPI is a "2 wire interface")
Between the controller and the cube it is still serial just de-multiplexed.
The ASICs themselves further demux because there are more cores addressable than a single SPI channel supports.
Iffin I recollect correctly the serial to and from the ASIC cores is unidirectional requiring a wire for each direction.
External to the FPGA are at least 12 seperate serial interfaces, 6(or12) for ASIC and 6 for DC/DC converters.
There might be 6 more for the LM75 not sure if it shares wire w/ VRM's.
The filename "spimux.rbf" tells us almost all we need to know if we recognise the jargon.
SPI=Serial Perephial Interface (a common industry interface)
mux=multiplexer
.rbf=compressed 'encrypted' proprietary Altera file format used to keep prying eyes like ours ignorant.
IMneverHO reverse engineering the FPGA even from decripted 'rbf' code would take an expert to understand.
Additionally the Cyclone IV can be turned into a CPU for clock request filtering purposes.
If kfc purchased the code to do this they "can't" release all the FPGA source because it is not theirs.
Another thing to keep in mind re: the FPGA.
The original FPGA sha256 code is the only diamond in the pile of shit that kfc has become.
The one and only technical competence (other than fleecing customers for NRE $) is their FPGA expertise.
Both the Pi and the BBB have an industry standard SPI interface.
If you bought something like this...
http://www.amazon.com/gp/product/B00BQA5BWU?psc=1&redirect=true&ref_=oh_aui_search_detailpageYou could make your own 'bridge' board for about US$8.00.
If you wanted to get real fancy add one of theese...
http://www.adafruit.com/products/2711Way less than the 0.5BTC I have seen mentioned.
You will need 2 or more power and ground wires, 2 SPI wires, and prolly some few others for LEDs etc.
I think you could run the power wires to the original Pi POWER connector and won't need a voltage regulator on the 'bridge' setup.
The Pi and the BBB do run on different voltages, it is one notable difference.
Ohm out each pin on the 'bridge' board and make a map for wiring.
You could probbably use a BBB instead of a Pi or a Pi instead of a BBB.
You would just have to adjust the SPI port setup in the firmware for any HW differences.
The various port pinouts of the Pi and BBB are easily findable.
https://www.google.com/search?q=Pi+SPI+pinout&ie=utf-8&oe=utf-8https://www.google.com/webhp?hl=en#hl=en&q=BBB+SPI+pinoutThe kfc source code for the SPI port setup on the BBB is online too.
I'm positive the only reason for the BBB to Pi change was for kfc to squeeze another US$10 out of each unit.
IMneverHO it would be easiest to port the Pi firmware to the BBB and forget about the voltage differences instead of 0.5BTC bandaid that still uses the Pi on a board designed for a BBB, FWIW. It might be as easy as changing the Pi header files with BBB header files and recompiling the utilities.
For those still on the quest for clocks, you might try using the 'raw' request type.
If it can be done with non FPGA software that is a potential vector.
I have no idea about on the 'tit' but, someone might try using an spimux.rbf from a hoopiter or a nepturd.
Don't forget you need to also set serial interface speeds in conf file if you try the hoopiter flavor.
If you want to spy on the communications between the controller and the cube it is simple also.
Purchace one of theese...
http://www.amazon.com/gp/product/B00BUH3R48?psc=1&redirect=true&ref_=oh_aui_search_detailpageand attach it to one of your ribbon cables, pay attention to the pin #1 markings! (a little triangle molded into the part)
and one of theese...
http://dangerousprototypes.com/docs/Open_Bench_Logic_SnifferThe logic sniffer is just an FPGA(cheaper/less capable than a Cyclone IV) doing almost exactly what the 'controller' board does BTW.
There already exist Cyclone IV development kits that could with the addition of any PC(or Pi, or BBB, etc,etc) replace the kfc controller board.
Could prolly even load and run the kfc "spimux.rbf" file.
https://www.google.com/search?q=EP4CGX22CF19C7N+development+board&ie=utf-8&oe=utf-8If you also installed a header into JP6 (the FPGA JTAG port) you can verify if the FPGA 'thinks' it's functional.
The logic sniffer above can do that too.
If all you wanted was JTAG info from the FPGA (to test FPGA functionality whilst troubleshooting controller boards)
one of theese...
http://dangerousprototypes.com/docs/Bus_Pirateor one of theese
http://www.ebay.com/itm/ALTERA-ByteBlaster-II-ALTERA-USB-Blaster-CPLD-FPGA-ALTERA-Download-Cable-JTAG-/271138629988might be a better choice.
Last but not least, pay close attention so you witness when the smoke comes out!
