I was thinking if there we can plug two optional cards. (one redundant power supply unit + -48V ) Unit (communications or Firewall use this kind of connectors usually ).
And Ethernet connector (G Ethernet ) in order to build a firewall with this main board.
As a firewall use no so much memory this build can fit with no problem.
Please, let me know it that is possible.
Other alternative for this board is build in a Daughter card with GPS, accelerometer (detect collisions ) and Bluetooth to connect with other devices in the car or bus. (currently some models for cars come with the connector to talk to the engine ) so how the driver use the car can be recorded and store in the memory card (if the bus is going in a road without cellular signal ).
This two applications I think can go viral.
Statistics: Posted by hmiranda — Tue Aug 06, 2013 9:25 am
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I'm exactly one of those people gbulmer has in mind: played around with microcontrollers and low speed peripherals (temperature and humidity sensors, RS485...) but I don't know enough about electronics to feel comfortable with high speed signals or other advanced stuff.
The perfect daughter card for me would look like that:
1.) There are 6 wires reserved on the opposite side of the first Ziport: SCLK, MOSI, MISO, 3xSS. Those are passed through the daughter boards without shifting.
2.) The daughter card lets me select which of the three SS I want to assign (jumper, solder-bridge, DIP switch, whatever).
3.) Right after the input and selector there is a level shifter which brings the SPI signals to 3.3V or 5V. (Would an optocoupler be slow? expensive? bad idea for another reason?)
4.) This is fed into an ATmega (can operate from 1.8V to 5V).
5.) The outputs of the ATmega go to the 0.1" headers.
There would be one "factory" preloaded firmware which transforms this card into an I/O card. I could certainly help with this firmware. Anyone else can grab a programmer (search for USBasp at eBay.com -> those are 7 USD including worldwide shipping) and do all the stuff gbulmer mentioned.
Actually the perfect board would also have
6.) 1-3 RC filters for ultra cheap and slow DAC (since the Atmels unfortunately miss those).
The ATmega probably costs the same as a single deserializer and you would have a board which could be made Arduino compatible, except for the form factor and the expensive USB port. ADCs, PWM, I2C, UART, everything there - for free!
As far as I understood the discussion, Al has two major concerns regarding gbulmer's proposal:
(a) giving up valuable high-speed "wires"
(b) added complexity when using a uC on the I/O board.
IMHO (a) is not really a problem: Having the 6 (or maybe even 8) wires there will be the default. If someone really wants to use all as Ziports you just need another configuration for the PL. Only if one specific card uses more than ~21 LVDS pairs, the card needs to violate the specification. Which doesn't matter, because then this would be the only card anyway.
Regarding (b): I think it's worth the trouble. And it would be feasible if there is only one default firmware.
I also think that an I/O card would need level shifters anyway. The advantage of my proposal is, that there are only unidirectional level shifters on the few SPI signals and everything else operates at the desired voltage. Most ATmegas can operate from 1.8V to 5.0V.
Many people use an Arduino connected to a PC for real-world connection. With this card you could have the Arduino including a dual core PC plus an Epiphany accelerator all in one (tiny) piece - smaller than an Arduino UNO!
Statistics: Posted by tschaboo — Fri Mar 01, 2013 8:36 am
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As I said, it has been a long time since I was doing embedded code, but it just seems a simpler solution than the (admittedly creative) zip-tab connector.
Jeff Naujok
Statistics: Posted by jnaujok — Thu Feb 28, 2013 7:34 pm
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I think the difference is significant enough, and the spread for Linux broad enough, to explain why I like MCU managed daughterboards. However, the article says that graph shows one of the two Zinq A9's running Linux, and the other an RTOS. I'd have to think about that approach, though it still feels like the bigger issue is easily adding the large range of peripherals via MCUs, rather than response time jitter.
Statistics: Posted by gbulmer — Thu Feb 28, 2013 1:12 am
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An AVR needs more than SPI MOSI, MISO and Clock for upload, it also needs Reset.
An STM32 needs more than UART Rx and Tx for upload, it also needs Reset and, at least BOOT0, to select between the manufactured-in System ROM bootloader, and booting from Flash. Ideally BOOT1 control would be available to select booting from RAM.
So, SPI, UART, at least 2 "GPIO" and power would be enough for a range of MCU managed daughterboards. Those interfaces would be sufficient for both programming and communications with the MCU. The two GPIO do not have high performance requirements, they would be toggling Reset and BOOT, so they could be provided by an I2C mechanism, but in the interest of simplicity, could be GPIO. Having all of those signals available on a single socket would reduce the part-cost of MCU-managed daughterboards.
Statistics: Posted by gbulmer — Sun Feb 24, 2013 6:46 pm
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This is what I had in mind :
So to "start", the FPGA just output '0' on the D line and then clocks like 30 times to 'flush' the chain. Then clocks out a '1'. It then reads the eeprom at address '1' (only the first board has this address, the other at at address 0). Then the fpga clocks out a '0', which puts back the first card eeprom to address 0 and puts the second card eeprom on address 1 by itself, and so on ...
Now, do daugther card need a global reset ... no idea. Could definitely be useful, I have to read the serdes chips datasheet more closely to see how to use them.
EDIT: There is even SOT23 EEPROM that could do (beware though, not all sot23 ones have address lines ! but some do). So that would make this circuit a total of 2 SOT23 component. Even if we can't use LED0/1, I think it'd be worth using 2 gpios of PEC FPGA for this. It might be possible to do it with a single one if really needed with a more complex circuitry on the daughterboards.
Statistics: Posted by tnt — Tue Feb 19, 2013 8:24 pm
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