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 Open Hardware Cypress FX2 based 8-channel logic analyzer.
- Optional: Make a tiny 3D-printed enclosure, and/or an "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
- 0.8mm PCB thickness, 5mil traces, 6mil trace clearance, 8mil via drill hole diameter, 5mil annular ring.
- Double-sided 2-layer 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.
- No buffer or other input 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, PCB layout and Gerber files are available from the fx2grok git repository:
$ git clone git://sigrok.org/fx2grok
Schematics, PCB layout, 3D preview
Schematics
PCB layout
3D preview, top
3D preview, bottom
Bill of materials
| Qty | Device | Footprint | Size | Value | Refdes | Digikey | Mouser | Comments |
|---|---|---|---|---|---|---|---|---|
| 1 | Cypress CY7C68013A-56LTXC | QFN-56 | 8mm x 8mm | — | IC1 | 10.05€ | 10.30€ | Main chip. Alternatives: eBay: 4.07€ (but who knows if it's fake), Future Electronics: 6.55€ |
| 1 | Amphenol FCI 10118192-0001LF | custom | 9.8mm x 5.6mm | — | U1 | 0.38€ | 0.35€ | USB Micro-B SMD connector |
| 1 | Murata XRCGB24M000FAN00R0 | custom | 2mm x 1.6mm | 24MHz | Y1 | 0.29€ | 0.46€ | 24MHz crystal |
| 1 | Micrel MIC5504-3.3YM5-TR | SOT-23-5 | 2.9mm x 1.6mm | 3.3V | U2 | 0.10€ | 0.10€ | 3.3V LDO |
| 1 | Amphenol FCI 20021111-00010T4LF | custom | — | — | P1/P2 | 0.53€ | 0.55€ | 5x2 through-hole pin header (1.27mm pitch), soldered to the PCB (5 pins per side) |
| 1 | Amphenol FCI 20021311-00010T4LF | custom | — | — | — | 0.68€ | 0.69€ | 5x2 connector/receptacle (1.27mm pitch), could be used for the probe cable |
| 5 | Resistor | 0402 | 0.25mm x 0.125mm | 2.7 kΩ | R2, R3, R4, R5 | ... | ... | ... |
| 1 | Resistor | 0402 | 0.25mm x 0.125mm | 100 kΩ | R1 | ... | ... | ... |
| 9 | Ceramic Capacitor | 0402 | 0.25mm x 0.125mm | 100nF | C2, C5, C7-C8, C10-C13 | ... | ... | ... |
| 2 | Ceramic Capacitor | 0402 | 0.25mm x 0.125mm | 1uF | C1, C14, C16 | 0.15€ | 0.09€ | ... |
| 3 | Ceramic Capacitor | 0402 | 0.25mm x 0.125mm | 2.2uF | C3, C6 | 0.08€ | 0.08€ | ... |
| 2 | Ceramic Capacitor | 0402 | 0.25mm x 0.125mm | 12pF | C4, C9 | ... | ... | ... |
| 1 | LED | 0402 | 0.25mm x 0.125mm | — | D1 | ... | ... | ... |