Frequently asked questions/Heat and power
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Can thumbstix power a verdex configuration?
No, thumbstix cannot power a verdex configuration as the PXA270 chipset does not allow proper operation of the verdex motherboard when combined with the thumstix expansion board.
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Can thumbstix power a wifistix, netDUO, netCF or netMMC configuration?
No-- the thumbstix board cannot supply enough power for a configuration including any of the netstix boards - netMMC, netCF, netDUO, netDUO-mmc, wifistix or wifistix-cf etc.
When should a 4v power supply be used? When should the 5v supply be used?
For any configuration that includes the netDUO-mmc expansion board, use a 4v power adapter.
For configurations including USB host power, a 5v power adapter should be used.
For all other configurations, either a 4v or 5v power adapter may be used.
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Does using 5v help when adding other devices to the GPIO lines, or give slightly more distance on the bluetooth connection?
All boards except the robostix regulate the input voltage to 3.3v. Higher input voltages just generate more heat.
Can ANY wall power adapter be used with gumstix products?
A wall adapter from Gumstix, Inc. is the best choice to use with any gumstix configuration as Gumstix only sells wall adapters which have a 5v regulated output.
Any wall adapter not sourced from Gumstix, Inc. needs to be checked closely as many wall adapters have an unregulated voltage output, which means that the voltage may be around seven (7) volts.
Check the output voltage on a scope to see the voltage that is being produced by the third-party wall adapter before using it on a gumstix product.
Can just one power supply be used for two or three board configurations?
Yes, only one power supply is needed.
The gumstix power bus connects all the boards and power connectors to each other: multiple connectors allows flexibility.
For example, using the "etherstix pack", connect both the etherstix and the waysmall STUART to the gumstix connex platform and use one wall adapter connected to the input jack on either the etherstix board or the waysmall board - whichever suits the needs and physical layout requirements best.
Is additional power needed for any of the netstix line of dual function expansion boards beyond that provided by a single power supply?
No, additional power is not needed. Power supplied anywhere along the common power bus is shared by all connected platforms and boards, including the netstix line of expansion boards.
When both a 92-pin and a 60-pin expansion board are connected to a gumstix connex, and both have a power supply connector, which power input jack should be used?
It doesn't matter which power input is used — the gumstix power bus connects all the boards and power connectors to each other: multiple connectors allows flexibility.
For example, with the "etherstix pack", if both the etherstix and the waysmall STUART are connected to the gumstix connex platform, the wall adapter can be inserted into the input jack of either the etherstix board or the waysmall board - whichever suits the needs and physical layout requirements best.
When using the robostix board, can any power input jack be used?
Power should always be provided via the robostix power jack when a robostix is being used. See Robostix Voltages.
Can the waysmall computer or any of the console expansion boards be powered via their usb port?
No, none of the waysmall computers or console expansion boards may be usb-powered via their usb port.
Can a connex or verdex configuration be powered via a USB cable ?
Gumstix engineering has not tested this method of providing power via USB but suggests that a connex and verdex configuration may be able to be powered from a host computer and a USB cable.
- On the breakout-gs and console-st boards, FB2 is populated with an SMD component - a resistor - that needs to be replaced with a ferrite bead as the FB is supposed to be a ferrite bead to accept USB power.
Note - The ferrite beads tend to be square in cross section. The resistors tend to be fairly flat in comparison.
Note - The resistors have their resistor code written on them as a 3 digit number. You'll see a couple with 103 (10K) and 203 (20K). The ferrite beads have no writing on them.
- The console-vx and breakout-vx boards should come configured with the ferrite bead.
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An old, obsolete version of the PXA255 reference manual, section 4.2 "Bus Powered Device", claims that the PXA255 cannot be used as a "bus powered peripheral", and gives a brief technical reason. But does that reason really apply when connecting it to a typical PC?
Has Power over Ethernet support been considered?
Yes, PoE support is being considered by gumstix product management and engineering.
What are the power specifications for the gumstix boards?
At 4.5V:
- 99MHz CPU, 50MHz bus, idle: 0.01-0.02A
- 200MHz CPU, 100MHz bus, idle: 0.03-0.04A
- 400MHz CPU, 100MHz bus, idle: 0.06A
- 200MHz CPU, 100MHz bus, 100% CPU usage: 0.12A
- 400MHz CPU, 100MHz bus, 100% CPU usage: 0.22A
These power requirements are approximate.
Note also that the PXA bus to RAM can go up to 133MHz depending upon the components chosen, which might well increase things like FFT performance.
What are the power specifications for the gumstix boards?
Basix and Connex At 4.5v
| CPU speed | Bus speed | CPU Usage | Current |
|---|---|---|---|
| 99MHz CPU | 50MHz bus | idle | 0.01-0.02A |
| 200MHz CPU | 100MHz bus | idle | 0.03-0.04A |
| 400MHz CPU | 100MHz bus | idle | 0.06A |
| 200MHz CPU | 100MHz bus | 100% CPU usage | 0.12A |
| 400MHz CPU | 100MHz bus | 100% CPU usage | 0.22A |
These power requirements are approximate.
Note also that the PXA bus to RAM can go up to 133MHz depending upon the components chosen, which might well increase things like FFT performance.
For benchmarks achieved by the gumstix products, go here.
Temperature Specifications
For the temperatures specifications, go here.
What kind of heat does gumstix produce?
The gumstix usually consumes < 1 Watt and can consume as much as 3W under a full load. We suggest measuring individual configurations and loads especially for designs that will be cased.
Can the gumstix be operated in Industrial environments and temperatures?
The gumstix is currently designed for commercial use only, even though many of the components meet industrial specification. OEMs wanting industrial specification boards may contact sales at gumstix.com for a quote and further information.
What min and max voltages can the Vbatt connections on the Hirose handle?
The voltage needs to be 3.5V to 6V. 3.5V is very close to the limit though — an accurate and reliable 3.5V works, but if you use only 3.47V, then the gumstix will not function.
Generally, it is safest to provide 3.6 Volts or higher.
How long should Li AAA batteries last?
Li AAA batteries should power the gumstix for about 6 hours, with average use, according to some customers.
Molecular just measured > 6h using 3 NiMH 1000mAh AAA cells on a connex 400-bt plus audiostix2 with bluespam bt scanner active and no special power-managment or turning off GPIOs (factory gumstix-root r1168, I think).
Is the gumstix US wall adapter "universal"?
The US wall power adapter can accept 110-240V at either 50 or 60Hz — but the physical plug shape is US: With a plug-shape-changing adapter, the US wall adapter will work at 240V.
Note that UK and Euro wall adapters are available here.
Australians can visit Dick Smith Electronics and purchase a "Multi-Reverse Earthed Adaptor" M7323.
At least one of the chips on the EtherStix and the netstix expansion boards gets quite warm (ok, pretty hot actually). Is this ok?
The SMC91C111 chip gets warm. We do not believe that it requires a heatsink for long-term use, and the heat generated will not impact the gumstix or the expansion boards as long as there is decent dissipation from the board (ie don't encase it in a strong thermal insulator).
A typical plastic case around the boards should not cause problems though (although this might get warm to the touch).
It is best to use 4v wall adapters for configurations that do not include a robostix board.
