Am 12.09.2014 um 15:58 schrieb Grazvydas Ignotas notasas@gmail.com:
Hi,
On Thu, Sep 11, 2014 at 3:05 PM, Dr. H. Nikolaus Schaller hns@goldelico.com wrote:
here a short update of the hardware test results (the 3.17 kernel git is updated accordingly trying to make things work).
First, let's start with what has already been tested and is working fine:
• Keyboard-Backlight LEDs • Shoulder Buttons • Nub buttons • Nubs (Position etc.) • Keyboard • Sensor: BMP180 (digital barometric pressure sensor) • DC/DC-Converter for the USB-Hosts ports • magnetic lid detector
Not yet tested:
• RGB-LEDs
have been fixed (hardware issue). Just one flaw: the red LEDs glow a little even if turned off. We need to rewrite the tca6424 driver so that gpios can be configured as "open drain" outputs: http://projects.goldelico.com/p/gta04-kernel/issues/658/
I hope such setup doesn't waste power..
Only the current one. If the outputs are controlled through I2C as open-drain, they don’t waste power if the LEDs are turned off. The problem is that they can’t be turned completely off through the current linux driver.
What the TCA6424 driver currently does:
set-direction: make it input or totem-pole output set-value: set output to 0V or 1.8V
what we need is some property "oc-outputs = <3, 4, 7, 11>" in the DT
set-direction: make it input or OC/OD output set-value: 0: make it output and 0 value (pull down), 1: make it input (open collector/drain)
• Stresstest VBUS
the vbus voltage breaks down at ~11 Ohm load which means 450 mA. This is a little lower than expected and required (should be at least 500 mA - better 1A). vbus can be turned on/off through GPIOs. The next version of the main board will indicate over-current (either through red LEDs and/or GPIOs)
We had lots of issues with this on pandora, some of which were never resolved. First MWeston found that some rotational USB drives use excessive current while spinning up, > 1A. Pandora can do a bit over 1A, but still there were reports on the forum that some drives don't start up without powered hub. Not much can be done about that I guess, but still I think we need to be able to supply at least something close to 1A and surely not 450mA.
Then there was an issue that the LCD was powered from the same power supply as VBUS, and connecting a drive would make the backlight flicker wildly, so we need a dedicated supply (maybe it already is in your design, I don't know how to check).
Later it was found that overcurrent protection doesn't actually work. I'm not sure if it was ever fixed.. There was even report of a burned board from USB HDD user. The LCD got it's own supply for rebirth.
Last and most annoying thing is that turning off VBUS over GPIO on pandora wastes more power than the whole OMAP3 with LCD off (no idea why), so we never turn off VBUS on pandora.
I really hope it will all work properly this time..
• Microphone-Detect-Switch
the TS3A225E works fine if accessed through I2C. A new test script is here: http://git.openpandora.org/cgi-bin/gitweb.cgi?p=pyra-kernel.git;a=commit;h=3... It even sends the mic_present signal to the TCA6424 which even raises the INT GPIO (can be checked by exporting it and reading from /sys). But the kernel does not handle changes as IRQ and they don't arrive in the extcon-gpio driver as expected.
• CPU-Reset-Logic (LSH-BOTTOM + Poweron)
this circuit is broken and needs to be redesigned.
• Charger-Bypass
works (except some insignificant issue which can be solved later - if at all).
Could you explain what that is? Powering the device without battery perhaps?
The charger bypass forwards the 5V VBUS from the secondary USB port to the OTG port so that connecting a wall charger to the secondary port can also charge the battery.
The small issue is that if you power the OTG port by a wall charger you will see 5V on the secondary port - which isn’t an OTG. And the circuit should have interrupted that path - but did some latch-up.
But since it only happens if you have 5V on the OTG port through an external charger it is IMHO insignificant.
Anyways, while working on the CPU board design I found that we already have a 5V step-up-converter for the OTG mode on the CPU board (provided through the Palmas chip). This should allow to use a different battery charger which has two separate power inputs (BQ24161B) instead of a built-in OTG power converter like the BQ24297. So if we replace the charger chip the problem mentioned above will simply disappear (any may be replaced by other problems I don’t see yet).
• FTDI232 (Linux console)
responds on the USB side.
Again, I hope it doesn't waste power..
• Charger
the charger chip behaves sane and expected (as far as it could be tested without real battery and system consuming high energy). A preliminary I2C driver for the bq2429x has been added. But the charger should also work without driver.
• Vibration motor, Microphone, Speakers
not yet tested.
• Modem-USB, Modem-Ignite, GPS
not yet tested (was already tested in the previous design except GPS and new functions like new SIM card reader).
• INA231 (for checking modem status/power)
a hardware issue prevents complete test.
• Fuel Gauge(s)
bq27200 responds but delivers unreasonable values. bq27421 does not respond.
• Other sensors
With pandora experience I feel uneasy with all these sensors.. I hope they all can be turned off or have good power management states, as on pandora nubs can't be turned off without wasting lots of power, again for unknown reasons..
Can't be tested yet (as we need the CPU-Board and/or the next revision of the motherboard: • HDMI • eSATA • USB-OTG 2/3 • Audio • WLAN/BT
I guess audio is still to be selected, like BT/WLAN?
Plan for Audio: TWL6040 (placed on the CPU board!) since it has the best and easiest system integration with OMAP5 and has all required features (incl. built-in amplifiers). Can be replaced together with the CPU. And, it allows to have more digital signal processing (easier to shield analog signals from noise, especially GSM buzz). Potentiometer will get an ADC to digitally control attenuation. Can also be (mis)used as another game control :) And attenuation can alternatively/additionally controlled by on-screen sliders or +/- buttons giving maximum flexibility in user interface.
Plan for BT/WLAN: WiLink6 WG7351 since the WiLink8 WG78xx modules by JorJin have less features and are bigger and unclear if they are really available.
BR, Nikolaus