Hi all,

I asked this weekend about the Palo35, because I was under the impression that the 3.5" LCD (77m x 64mm) was the smallest display one can mount to a Gumstix.

However, I now see that one can go considerably smaller, using LCD character displays such as available from NewHaven (i.e. the 41mm x 24mm NHD-C0216CZ-NSW-BBW-3V3, or the 40mm x 35mm NHD-0208AZ-RN-YBW-33V).

Currently, the largest board in our package is 41mm wide (we're targeting a handheld form-factor like a phone, so are less concerned with length than width), so this has us looking at the uber-thin Thumbo (76mm x 23mm).  I also dug around in a closet and found some packs of Verdex Pro XL6P, Console-VX, and NetPro-VX, which while a bit longer than the Thumbo, remain relatively thin, so I'd like to ask about them as well if I may.

Thumbo Questions

Q) The product page states that the Thumbo can be used with "any Overo COM without on-board wireless communications...such as the Overo Air COM or Overo Fire COM, [which] can draw more than 500mA".  My question: can you use an Overo Fire COM as long as you're not enabling WiFi/Bluetooth, or are these COMs totally incompatible with the Thumbo regardless of which features you enable?  (I ask because we have several extra Fire COMs already, which I'd like to repurpose for testing.)

Q) The product page says it has a "USB standard A plug with OTG signals (wired as a device)" -- does the mention of OTG mean that I can use the Thumbo as a USB Host, as long as I provide the standard-A gender-mender and provide external power?  Can I provide 5V power directly to the pins on the USB port, assuming I'm already providing my own battery pack and charger?

Q) The product page lists "level shifters for use with a set of test pads" -- can these "level shifters" allow us to use the 1.8v signal logic on the 60-pin header to communicate with a 3.3v card elsewhere in the system?

Q) Of the 60 1.8V signal pins, can the two "two-wire serial ports" be used as a UART?

Q) Of the 60 1.8 v signal pins, can the "one 1-wire port" be used as a gas gauge for communicating with a battery circuit?  That is, does it support TI HDQ?

Q) The SPI bus is 4-wire?

Q) Sadly, it looks like the 60-pin board only provides a single SPI bus, whereas I think I need two (one to control our sensor, and another to command the text display I'd originally identified).  I suppose I could try the 40mm x 35mm NHD-0208AZ-RN-YBW-33V, though I'm still trying to make sense of its pin-out.

Verdex Pro XL6P + Console-VX + NetPro-VX Questions

- according to the Verdex features, I can pull some serious UART action on these

Q) I assume I can build micro-SD images for the Vertex much like I do for the Overo COMs, just using different images?  Somewhat worrisomely, I don't see much on Sakoman.com for Vertex.  Is there an equivalent image store elsewhere?  (I don't necessarily need to update these to Ubuntu, but I'm not sure how long they've been in that closet, so I suspect I might want to refresh whatever I find on there.)

Q) I assume the USB mini-B connector on the Console-VX can mount a thumbdrive storage device, using a mini-B-to-A-receptacle adapter?

Q) This thing seems to have an insane number of available pins, but I'm not seeing an explicit "SPI bus" mentioned in the pin-outs.  Can such be found along one of these expansion boards?  (I do see some archive messages about people successfully getting the SPI demo to work on the Verdex, so I assume it's doable, I'm just not sure which pins they're using.)

Otherwise, while the stacked Verdex boards are closer to a hand-held form-factor than the Chestnut, they're still vastly larger than the Thumbo, so I'd really prefer to get that working if I can support power in, display out, SPI out, and UART in (can lose the USB in a pinch).

Thanks for any suggestions, and hope some of this makes sense ;-)

Mark Zieg
Ocean Optics


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