Neo FreeRunner Hardware Issues
This is a community-written page that discusses hardware issues with the Freerunner/GTA02 device. Information here is unofficial (and possibly incorrect) unless otherwise stated. Corrections and clarifications from Openmoko employees would be greatly appreciated.
Also please DON'T PANIC when reading this page. Please give Openmoko employees time to investigate these issues and to develop a solution. Some of the items may turn out to be non-issues, or may have software workarounds.
GPS Slow TTFF
Issue: The GPS signal is degraded to the point where the unit cannot reliably get a "cold-start" fix. See GPS_Problems.
Reason #1: For some reason, the MicroSD controller on the Freerunner is interfering with GPS reception.
Reason #2: Poor soldering and/or mechanical deformation of the internal GPS antenna connector on some devices. See FreeRunner_GPS_antenna_repair_SOP
Affects: unknown percentage of devices
Status of #2: unknown
Workarounds: Remove the microSD card. Use an external GPS antenna. Supplying almanac data and approximate coordinates in software (so that the chip can perform a "warm" acquisition) may also help.
Poor Audio Quality
Issue: The person on the other end of a GSM phone call may experience poor audio quality, to the point where he/she cannot carry on a normal conversation.
There are three related aspects to this issue:
- Call is too quiet (mixer settings for mic and/or earpiece are set too low)
- Caller hears a loud echo of their own voice #1267
- Buzzing noise caused by GSM radio interference #883 #1352
Affects: all devices but only some users (depending on many factors)
Status: Under investigation. There is a possibility that the quality can be made "good enough" through software (mixer settings).
Workarounds: Using a bluetooth headset is a possibility.
Issue: The device may fail to boot or charge the battery if the battery is deeply discharged (far enough that its internal protection circuitry is activated). See for example this thread on the kernel list.
If the battery's terminal voltage is low but greater than zero then the Neo1973 recovery method may work: Disconnect USB, remove the battery, wait 10 seconds, re-insert the battery, re-connect USB, let it charge for 1 hour (or more) without pressing any buttons.
Affects: Unknown. Some discussions on the mailing list may refer to pre-production devices.
Workarounds: See http://lists.openmoko.org/pipermail/community/2008-July/021556.html
Some SIMs Don't Work
Issue: There are reports that some users cannot register with their GSM network when using certain SIM cards. See for example http://lists.openmoko.org/pipermail/community/2008-July/020370.html
It is possible that there is more than one issue involved here. The observed problems might (i.e. some items are only speculation at this point) be caused by:
- User error, not inserting the SIM in the correct orientation or not sliding the holder to the 'locked' position
- Software issues that result in a locked SIM (not properly prompting the user for a PIN and then passing this to the SIM)
- Mechanical issues with the SIM holder that prevent the pins from making reliable contact with the pads on the SIM. Note that only 6 of the 8 pins are used, and the remaining two are not connected.
- Electrical incompatibility (some tests show problems with 1.8V SIMs while 2.9V ones work OK)
- Firmware bugs in the TI Calypso GSM chipset. Note that one issue in this category was found and fixed on the GTA01 devices (#666 in Trac), and that specific problem should not affect the Freerunner.
- Defective SIMs, i.e. ones that do not comply with the applicable standards and are acknowledged as being defective by the carrier (even if they happen to work in some phones).
Affects: Only a subset of users (details unknown).
Status: Under investigation
Workarounds: It may be possible to obtain a different model of SIM from your GSM carrier.
Empty NOR Flash
Issue: NOR flash (backup copy of u-boot) is not programmed. #1568
Affects: Unknown - maybe only 1 or 2 devices? Also need to confirm that the bug report was from a mass-production unit rather than an earlier prototype.
Workarounds: Use the NAND copy of u-boot and be careful not to brick the device unless a debug-board is available.
Debug board has wrong vendor/product ID
Issue: A debug board is not reporting the expected USB Vendor/Product ID.
Affects: Only one report has been seen so far.
Workarounds: Edit configuration files (e.g. openocd.conf) to use the IDs that the board is reporting.
Won't power on with dead backup battery
Issue: The device may not power on if the backup battery is deeply discharged. The backup battery is a small component soldered to the internal circuit board, and is used to maintain the PMU state when the main battery is removed. See discussion on the kernel list, and #1642
Status: Under investigation
Workarounds: Do not leave your device un-powered for a long period of time.
This section lists items that are acknowledged as being less than ideal, but are considered to be acceptable in the shipping product. They will not be discussed in detail on this page.
- Poor performance + slow bus speed of the Glamo GPU - discussed to death on the mailing lists and IRC.
- GPS antenna switch driven out-of-spec - does not appear to have a significant effect on device performance
- Poor low-frequency audio response with low-impedance headphones, e.g. as discussed in this thread: http://lists.openmoko.org/pipermail/openmoko-kernel/2008-March/001999.html (NOTE - this thread refers to pre-mass-production devices)
These are issues that have been discussed in the past, but have been fixed (or turned out not to be a problem) for the mass-produced devices.
- Excessive LED current - Some early units lacked a current-limiting resistor for the LEDs. This has been fixed for the production units.
- Battery life - At this time it appears that the Freerunner battery life will be acceptable once suspend/resume support has been implemented in software.