fx2grok
The fx2grok device is intended to be the tinyiest possible Open Hardware FX2 eval board (that can be used as 8-channel logic analyzer).
The schematics and layout are done from scratch in Kicad, and are released under the CC-BY-SA 3.0 license.
Using the open-source fx2lafw firmware (and sigrok, of course) you can use this device as 8-channel logic analyzer.
Goal
- Make the tinyiest-possible FX2 eval board / logic analyzer.
- Optional: Make a tiny "enclosure" using resin (example), with the device (including probes) ideally looking similar to the sigrok logo in the end.
What is NOT the goal?
As you may know, there are tons of FX2-based logic analyzers (and tons of clones) already. There's not much use in creating yet another "standard" device.
The goal of this little hobby project is thus NOT to make a better device, or to make a cheaper device, or anything like that. The only goal is to have it as tiny as possible (it's more of a "just for fun" project).
Hardware
- 13mm x 13mm PCB.
- Double-sided PCB/layout, 0402 SMD components soldered on both sides.
- USB micro-B connector.
- 1.27mm 5x2 pin header.
- FX2 in 56pin QFN package.
- Small SMD 24MHz crystal, or through-hole one with bent leads (less PCB space needed, but higher device).
- No buffer or other protection (not even 100 Ω resistors for each probe).
- No EEPROM, the device will enumerate with the standard Cypress FX2 "unconfigured device" USB VID/PID (04b4:8613).
Download
The schematics and PCB layout is available from the fx2grok git repository:
$ git clone git://sigrok.org/fx2grok
Bill of materials
| Qty | Device | Footprint | Size | Value | Refdes | Digikey | Mouser | Comments |
|---|---|---|---|---|---|---|---|---|
| 1 | Cypress CY7C68013A-56LTXC | QFN-56 | 8mm x 8mm | — | IC1 | 10.07€ | 12.00€ | Main chip. Alternatives: eBay: 4.04€ (but who knows if it's fake), Future Electronics: 5.52€ |
| 1 | Hirose ZX62-B-5PA(11) | custom | 9.8mm x 5.6mm | — | U1 | 0.98€ | 0.908€ | USB Micro-B SMD connector |
| 1 | Abracon ABM11-24.000MHZ-B7G-T | custom | 2mm x 1.6mm | 24MHz | X1 | 2.27€ | 1.96€ | 24MHz crystal |
| 1 | Micrel MIC5319-3.3YD5 | SOT-23-5 | 2.9mm x 1.6mm | 3.3V | U2 | 1.89€ | N/A | 3.3V LDO |
| 1 | FCI 20021111-00010T4LF | custom | — | — | P1/P2 | 0.66€ | 0.42€ | 5x2 through-hole pin header (1.27mm pitch), soldered to the PCB (5 pins per side) |
| 1 | FCI 20021311-00010T4LF | custom | — | — | — | 0.99€ | 0.49€ | 5x2 connector/receptacle (1.27mm pitch), used for the probe cable |
| 5 | Resistor | 0402 | 0.25mm x 0.125mm | 2.2 kΩ | ... | ... | ... | ... |
| 1 | Resistor | 0402 | 0.25mm x 0.125mm | 2.7 kΩ | ... | ... | ... | ... |
| 1 | Resistor | 0402 | 0.25mm x 0.125mm | 100 kΩ | ... | ... | ... | ... |
| 9 | Ceramic Capacitor | 0402 | 0.25mm x 0.125mm | 100nF | ... | ... | ... | ... |
| 2 | Ceramic Capacitor | 0402 | 0.25mm x 0.125mm | 1uF | ... | 0.071€ | 0.083€ | ... |
| 3 | Ceramic Capacitor | 0402 | 0.25mm x 0.125mm | 2.2uF | ... | 0.11€ | 0.066€ | ... |
| 2 | Ceramic Capacitor | 0402 | 0.25mm x 0.125mm | 12pF | ... | ... | ... | ... |
| 1 | LED | 0402 | 0.25mm x 0.125mm | — | ... | ... | ... | ... |