| Cyclone II and IV boards available. [message #1413] |
Wed, 14 December 2016 03:05  |
rhkoolstar
Messages: 276
Registered: October 2015
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Hi all,
I recently finished up the design of my compact Cyclone boards and, as usual, I now have a few boards left over. They come in both Cyclone II (green) and Cyclone IV (red) version. Both have facilities for a micro SD card socket, VGA, PS/2, 2x512 KByte SRAM and 4x serial interfaces (Full handshake). One serial interface (#4) can be fitted with an ESM 8266 module. The Cyclone II version also has an RCA video output. The boards are pin-compatible with the II-C and IV-B boards, except for the serial interfaces 3 and 4 on the II-C board and CTS-4 on the IV-C board. The PS/2 connector has both keyboard and mouse pins wired up (1-2 & 5-6). this prevents problems with some converter cables.
The boards can be fitted with TTL/USB cables (3v3) or with FTDI USB modules. If required, RS-232 modules (MAX 3232) can be plugged in (see picture for examples). All serial interfaces have current limiting resistors fitted as well as optional weak CTS pulldowns.
For SD card sockets and LDO regulators, pre-made modules (available on EBAY) are used. These come with built-in decoupling capacitors. One regulator is used for the ESP option, the Cyclone IV board uses the second for SRAM and SD-card. I use axial capacitors under the SRAM chips. I'll include these because you might not normally use this type, and I have hundreds...
I have about 8 boards of each type left over. If anyone is interested they are available for $5 each (incl shipping). The board costs $2.50, postage is $2.50 also (crazy, I know)
one board = $5.00 (2 stamps)
two boards = $8.25 (3 stamps)
You can only pay me if you actually have the boards drop on your doormat. I send them as letter post which seems to fail occasionally. Payment details will be in the envelope (Paypal). If money is tight you can also pay it forward (help someone else when the occasion arrises).
Alternatively you can have your own boards made, Kicad gerbers are included.
Be well... Rienk
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Attachment: CII.pdf
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Attachment: CIV.pdf
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Attachment: CycloneII.zip
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Attachment: CycloneIV.zip
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| Re: Cyclone II and IV boards available. [message #1436 is a reply to message #1435] |
Tue, 20 December 2016 13:05  |
rhkoolstar
Messages: 276
Registered: October 2015
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Senior Member |
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Hi Neal,
I don't think there is a possible way of connecting a decoupling cap with shorter leads. It is connected straight between the VCC (pin 32) and VSS (pin 16). Also there is no secondary current in those leads.
Lead length is directly related to the highest frequency used. With our configuration, a highest frequency of 300 MHz (3 ns pulse rise) gives a wavelength of 2.10^8 / 300.10^6 equals .66 metres (26 inch). (I assume a dielectric constant of 2/3 ( now I show my age, this should be called relative permittivity now, I believe) . You run into trouble when you approach a quarter wavelength (16 cm or 6.5 inch)
Now when you start using GHz signals the 6 mm value would not seem unreasonable.
I would not worry too much about it.
I like Kicad. I have used ink on copper, rub-on decals for the island, crepe tape, later with ORCAD/LAYO1 I was able to make double sided boards. I did some Eagle and now Kicad.
I made some scripts to convert Eagle footprints to Kicad, with some success, but I am still struggling with arcs.
I think I'll stick with Kicad / Freerouting, I like open source, It runs on Linux and there seems to be some preference in this group for it. You will have to put some effort into it, but what else is new...
With PCB manufacturing available to the hobbyist the way it is now, I think it is a valuable skill to have.
Rienk
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| Re: Cyclone II and IV boards available. [message #8044 is a reply to message #7970] |
Thu, 22 October 2020 11:37 |
tingo
Messages: 112
Registered: February 2017
Location: Oslo, Norway
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Senior Member |
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Finally managed to solder up the Cyclone II board I have, see picture. Before I power it up, I have a couple more questions:
1) what is the pinout of the connector for the ftdi modules? I think it is (from left to right when you can read "FTDI232"): gnd, cts, vcc (not connected), txd, rxd, rts
2) SDsocket pinout: I think it has gnd on the left when you can read "SDSocket", is that correct?
The schematic posted doesn't quite correspond to the layout of the PCB, so I figured it was better to ask first.
Torfinn
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| Re: Cyclone II and IV boards available. [message #8051 is a reply to message #8046] |
Mon, 26 October 2020 11:03 |
tingo
Messages: 112
Registered: February 2017
Location: Oslo, Norway
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Senior Member |
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Ok, so my AS6C4008-55PCN chips are bad / not working (I used Camelforth from this page to test). I have some AS6C1008-55PCN chips as well, but checking the datasheet I see that they are not entirely pin compatible (they have a CE2 on the same pin that the 4008 have A17).
So I will have to change the VHDL code in order to use these chips, right? (I was thinking I could use them for testing at least).
Torfinn
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| Re: Cyclone II and IV boards available. [message #8059 is a reply to message #8056] |
Wed, 28 October 2020 09:12 |
tingo
Messages: 112
Registered: February 2017
Location: Oslo, Norway
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Senior Member |
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In other news, today I got new AS6C4008-55PCN chips (ordered from RS Online this time) and with two of those installed my Multicomp II-c board (lookalike?) works nicely, both multicomp09 / Camelforth and multicomp cp/m. So the previous AS6C4008-55PCN memory chips are not working correctly.
Torfinn
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