Messages

1

Cosmo Communicator - Hardware / Re: New Batteries Anywhere? (Shipped to USA)

« on: September 23, 2023, 10:37:26 am »

I went a similar route - details at https://www.oesf.org/forum/index.php?topic=36950.0 :-)

2

Cosmo Communicator - Hardware / Successfully replaced the battery with a third party one

« on: September 23, 2023, 10:26:38 am »

My cosmo had a inflated battery as well. I searched for a third batttery which fits into the cosmo (soldering is fine for me), but the biggest problem was the required thinness of the battery (original name: SXX600, original size: 13.6 x 6.2 x 0.3 cm, original capacity: 4220 mAh)

Eventually, I stumbled over https://www.ampul.eu/de/batterie/4452-li-pol-akku-3000mah-37v-306090, which is  9.0 x 6.0 x 0,3 cm and has 3000mAh. The size is almost perfect - 2 dimensions are fitting completely, the other being about 4 cm less. Which is actually rather good, because this way I have some space for the cable. soldering etc.

Both batteries - the old and the new - have a tiny pcb with 2 (dual) mosfets and a tiny controller. On the original pcb, there is not only P+/P- on the connector, but also an ID and a "Test" line (is written on the connector cable). I used both PCBs - the old one for satisfying the id+test lines, the new for a additional safety layer. And because it was the easiest way :-D

My biggest fear was that the pcb locks itself if there is no voltage anymore on the battery cell side as a safety measure (quite common on laptop batteries). To avoid that, you have 2 choices: temporary connect an external power supply ( 4,4V, 100...200 mA will do), or connect the old and new battery in parallel. I went the second way, which is easier, but needs a bit of preparation.

The main problem is to prevent a high current at the moment of connecting the both batteries.

Luckily, my old battery had already a quite big impedance because of its defect. If you have a power supply with adjustable voltage and current (or a current limit of max. about 2A): Measure the voltage of the battery (in my case: 2.9V) Then apply a voltage of 0.1 V (max. 4.4V) more than that. If the current is less than about 1 A (typically: _much_ less, 50 mA is a typical value): Go up to 4.4V (or, if you have already the new battery: 0.1V more than that, should be about 3,7... 4.2V, mine had 3,9V). If the current stays under 1 A the old battery is either full or has an high impedance. Both is good.

If the old battery has an _higher_ voltage: discharge it until the voltage is a bit under the new battery.

The old cell was connected to its PCB via contact welding the connectors. Luckily, soldering right on the connectors works fine. So I soldered first the black wire of the new battery on the old PCB (mind the polarity, there is also a "B-" on the PCB). Then I hold the red wire on the B+ connector on the old PCB. No smoke ( :-D ), so I soldered the red wire on it as well. Then I disconnected the alu connector of the old cell with a scissor (please do not short anyshing :-) ). Then I isolated everything, taped it with duad side tabe and screw everything together again.

Result:
1. Cosmo started, displaying a SoC of 64% and 3.9V
2. It charged fine and linearly up to 100%
3. It discharged fine and linearly up to 0%, lasted the predicted time (about 11 hours with quite a load - hint: disabling the cover connection with the app and the cover in the "quick selection" area helps ;-) )
4. It chaged finde and linearly up to 100% again, with an internal measured (with AIDA64) energy of 2946 mAh - perfect strike :-)

Pictures:
 

 

P.S. This should work on the gemini as well.

3

Cosmo Communicator - Hardware / Solution for sometimes not detecting the SIM

« on: September 23, 2023, 10:24:58 am »

Sometimes, the SIM is not detected. You see the problem here: 

The carrier shorts the contact fields of the SIM. Solution: Tape :-D

4

Cosmo Communicator - Android / Usage of other file systems than FAT32 for the sd card

« on: March 22, 2020, 07:23:42 am »

One (little) feature request: As the system already uses ext4 for internal partition, please allow the usage of ext4 partitions in the "shared medium" variant of the sd-card as well. exfat would be even better ;-) Currently, only fat32 is permitted, which can't handle files bigger than 4 GB, which is a problem for e.g. offline wikipedias. Android wants to format sdcard with any other file system.

I know that there are unofficial ways for rooted Android, but this would be a nice (and probably easy) feature for the "normal" Android.

5

Cosmo Communicator - Android / Modem only working on none-rooted android?

« on: March 04, 2020, 08:31:27 am »

I rooted my cosmo the "official" way, ie installed the rooted kernel in one of the slots (should be EMPTY_NORMAL_BOOT_3 or EMPTY_NORMAL_BOOT_4). The problem is that the SIM card is only detected in normal (non-rooted) android, not in the rooted version.

Can it be that lk does initialize the modem only when booting from the normal android boot partition?

6

Cosmo Communicator - Linux / TWRP in boot 2 partition ( empty_recovery_boot_2 )

« on: February 14, 2020, 09:49:46 am »

Hmm, for me it is working... Despite having problems unlocking the user partition (I didn't activated the encryption...)

Did you install twrp from the zip file ( link above ) ?
Thanks

Yep, I used the one at http://support.planetcom.co.uk/download/co...taller-beta.zip . Note that it shows the TWRP logo for 1-2 minutes before giving up on decrypt the user partition. And I repartitioned the system before (60/60).

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Cosmo Communicator - Linux / TWRP in boot 2 partition ( empty_recovery_boot_2 )

« on: February 14, 2020, 03:47:22 am »

Hmm, for me it is working... Despite having problems unlocking the user partition (I didn't activated the encryption...)

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Gemini PDA - General Discussion / Firmware causes wifi mac address change on reboot

« on: January 10, 2020, 07:01:47 am »

Just change the 5th bytes onwards from the 00  to your current mac (use e.g. ifconfig for this), than press ctrl+c to save and exit.

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Cosmo Communicator - Hardware / Serial Console

« on: November 29, 2019, 04:15:11 am »

Wasn't this more a built-in feature of the geminis SoC + the bootloader?

Additionally, I think the microcontroller of the cover display is connected with something simple - straight uart, i2c or spi. This could be used for debugging as well

P.S. The forum server throws a lot of http 500...

10

Cosmo Communicator - Hardware / USB-C

« on: March 13, 2019, 07:58:21 pm »

At least for me, also the right side of the Gemini supports the hub.

11

Gemini PDA - Linux / Mainline linux kernel

« on: August 13, 2018, 02:01:57 am »

hmm, 4.19 seems to have a lot of cool stuff for x20 /mt 6797  https://www.phoronix.com/scan.php?page=news...-4.19-ARM-Early

12

Gemini PDA - General Discussion / 4G Gemini as main device ?

« on: August 13, 2018, 01:57:16 am »

I use it as my main phone - and also as main laptop for the "little" things

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Gemini PDA - General Discussion / Games on Gemini

« on: August 13, 2018, 01:52:23 am »

Manaplus (free and open source MMORG) works fine

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Gemini PDA - Hardware / Supplied charger supports MTK Pump Express

« on: July 01, 2018, 04:34:19 am »

I measured it some time ago - there are going 1,5A by 5V over the USB cable. Which are 7.5W - which is ok I think.

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Gemini PDA - Hardware / Displaylink adapter works (under Android)!

« on: July 01, 2018, 04:28:31 am »

I tried a (random dual output USB 3.0 which I bought several years ago) Displaylink adapter on the right side. And it worked flawlessly after installing the Displaylink app :-) Only problem is that in OpenGL ES apps the external display doesn't work (Tested with supertuxkart).
It even works in combination with the Gemini Hub and without a external power supply.

So there is finally a way to have power, USB and external display at the same time :-)

I'll add the type of the adapter tomorrow when I have access to it again.