qnhoang81
Posts: 18
Joined: Wed Feb 15, 2017 1:03 am

Re: problems setting raspberry pi up with lapdock 500

Mon Apr 24, 2017 11:38 am

I'm not sure regarding this cable since I can't see the schematic just by looking at the outside, but the switch is not at the connector end. It won't work unless you short the pins at the site of the connector.

cHunt
Posts: 1
Joined: Sun Apr 22, 2018 4:13 am

Re: problems setting raspberry pi up with lapdock 500

Sun Apr 22, 2018 4:36 am

I know this is a pretty old thread but I wanted to share my experience with the lapdock 500 since i found a couple on ebay for $20.
This thread came up a lot during my searching.
Im not using a raspberry pie but I think the issues are the same.

Usb cable, if you use a break out board or cut up a cable, the micro usb connector needs the "ID" pin to be momentary placed to the vcc pin to activate the usb hub and turn on the hdmi chip.

The hdmi chip needs to see hdmi signal to stay on. The beaglebone black required me to edit the /boot/uEnv.txt file.
I added "video=HDMI-A-1:[email protected]" to the "cmdline=" command to force an hdmi mode and resolution.

The line looked like this
"cmdline=coherent_pool=1M quiet video=HDMI-A-1:[email protected] cape_universal=enable"

I don't think all resolution will activate the hdmi chip in the lapdock, the above does work.
After a reboot, I do need to pull the "ID" pin to 5v to re activate the monitor.

On the PI, i think the option in config.txt are the key,
From earlier in this thread:
hdmi_force_hotplug=1
hdmi_drive=2

I think these options would make it more reliable.
hdmi_group=2 // changes mode to set resolution different than standard hdmi settings
hdmi_mode=39 //set 1360x768 60Hz

possibly
hdmi_ignore_edid=0xa5000080

Good Luck
Thanks for the help, all the previous comments got me to a working screen.

cookin1983
Posts: 25
Joined: Thu Aug 01, 2013 9:57 pm

Re: problems setting raspberry pi up with lapdock 500

Sun Apr 22, 2018 8:00 pm

Thanks for the info. I'll try it out some time.
cHunt wrote:
Sun Apr 22, 2018 4:36 am
I know this is a pretty old thread but I wanted to share my experience with the lapdock 500 since i found a couple on ebay for $20.
This thread came up a lot during my searching.
Im not using a raspberry pie but I think the issues are the same.

Usb cable, if you use a break out board or cut up a cable, the micro usb connector needs the "ID" pin to be momentary placed to the vcc pin to activate the usb hub and turn on the hdmi chip.

The hdmi chip needs to see hdmi signal to stay on. The beaglebone black required me to edit the /boot/uEnv.txt file.
I added "video=HDMI-A-1:[email protected]" to the "cmdline=" command to force an hdmi mode and resolution.

The line looked like this
"cmdline=coherent_pool=1M quiet video=HDMI-A-1:[email protected] cape_universal=enable"

I don't think all resolution will activate the hdmi chip in the lapdock, the above does work.
After a reboot, I do need to pull the "ID" pin to 5v to re activate the monitor.

On the PI, i think the option in config.txt are the key,
From earlier in this thread:
hdmi_force_hotplug=1
hdmi_drive=2

I think these options would make it more reliable.
hdmi_group=2 // changes mode to set resolution different than standard hdmi settings
hdmi_mode=39 //set 1360x768 60Hz

possibly
hdmi_ignore_edid=0xa5000080

Good Luck
Thanks for the help, all the previous comments got me to a working screen.

cd85233
Posts: 1
Joined: Thu Apr 26, 2018 2:28 am

Re: problems setting raspberry pi up with lapdock 500

Thu Apr 26, 2018 2:35 am

Hey guys! Just joined the forum to say thanks to all of you guys and to post some of the issues I ran into and maybe some light for those trying it out.

1. VCC (+5) does not go to the pi. It is only used to jumper ID + VCC on the lapdock. It took me a while to see the schematic posted earlier didn't have VCC as a pass through...My dumb mistake.

2. These two parts fit REALLY well on the connector and make life easy:
https://www.amazon.com/gp/product/B0183KF7TM/
https://www.amazon.com/gp/product/B00KMR6XWK/

3. Add HDMI_SAFE=1 to you /boot/config.txt to get the screen working reliably.

I got mine working perfectly fine. I'll probably set up the battery internally to power the pi in a bit and see if that works well.

Thanks again for everyone that posted so much info. Made the project pretty simple.

tm314159
Posts: 5
Joined: Sun Apr 29, 2018 7:37 am

Re: problems setting raspberry pi up with lapdock 500

Mon May 07, 2018 3:21 am

I bought a Lapdock 100 and 500 a while back and stumbled on this thread via Google.
I have mine working, so here' s a few things I've noticed.

1) You don't need a switch to momentary connect the USB ID (sense) pin to the host +5v.
I leave mine soldered and it works fine.

2) The Lapdock 100 works fine on the Raspberry Pi with only the USB sense pin mod.
The Lapdock 500 pro also requires forcing the HDMI output to 1366x768.

3) The Lapdock 500 seems to return the wrong video modes via HDMI EDID which confuses the Raspberry Pi.
This seems to be why forcing the HDMI video mode is required.
My guess is the EDID returned by the Lapdock 500 is wrong.
If the EDID information were fixed, the correct resolution could be automatically selected.

4) EDID seems to be an I2C protocol, so there should be an I2C EEPROM on the Lapdock 500 motherboard.
I'm guessing it's stored on U13, which is labeled "ATMLH132" which is a 128k x 8 serial EEPROM.

So basically in order to fix the problem, it seems to require reprogramming the ATMLH132 with fixed EDID information.

Toshi

tm314159
Posts: 5
Joined: Sun Apr 29, 2018 7:37 am

Re: problems setting raspberry pi up with lapdock 500

Tue May 08, 2018 7:10 am

OK, I understand the problem.

Here's the Lapdock 500 EDID dump using tvservice:

00000000 00 ff ff ff ff ff ff 00 35 f4 c6 3d 01 00 00 00 |........5..=....|
00000010 23 15 01 03 81 1f 11 78 ee 85 94 99 57 4f 8f 26 |#......x....WO.&|
00000020 21 50 54 00 00 00 01 01 01 01 01 01 01 01 01 01 |!PT.............|
00000030 01 01 01 01 01 01 11 1b 56 72 50 00 0c 30 30 20 |........VrP..00 |
00000040 25 00 35 ae 10 00 00 1e d7 09 80 a0 20 e0 2d 10 |%.5......... .-.|
00000050 08 60 22 01 80 e0 21 00 00 18 d7 09 80 a0 20 e0 |.`"...!....... .|
00000060 2d 10 08 60 22 01 80 e0 21 00 00 18 8c 0a d0 8a |-..`"...!.......|
00000070 20 e0 2d 10 10 3e 96 00 d0 e0 21 00 00 18 01 e1 | .-..>....!.....|
00000080 02 03 0c 00 23 09 02 40 83 01 00 00 00 00 00 00 |....#[email protected]|
00000090 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
000000a0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
000000b0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
000000c0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
000000d0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
000000e0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
000000f0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ff fe |................|

When this EDID is run through edid-reader, it print this:

Descriptor 1
Detailed Timing Descriptor
Pixel Clock: 69.29MHz
Horizontal Active: 1366
Horizontal Blanking: 114
Vertical Active: 768
Vertical Blanking: 12
Horizontal Sync Offset: 48
Horizontal Sync Pulse: 32
Vertical Sync Offset: 2
Vertical Sync Pulse: 5
Horizontal Display Size: 309
Vertical Display Size: 174
Horizontal Border: 0
Vertical Border: 0
Interlaced: false
Stereo Mode: 0
Sync Type: 3
2-Way Line-Interleaved Stereo: false

So apparently the 1366x768 mode wants a pixel clock of 69.29 Mhz which is nonstandard. For reference, here's the Lapdock 100 EDID:

00000000 00 ff ff ff ff ff ff 00 35 f4 c5 3d 01 00 00 00 |........5..=....|
00000010 23 15 01 03 80 16 0d 78 ea 0d c9 a0 57 47 98 27 |#......x....WG.'|
00000020 12 48 4c 00 00 00 01 01 01 01 01 01 01 01 01 01 |.HL.............|
00000030 01 01 01 01 01 01 20 1c 56 c2 50 00 26 30 3b 27 |...... .V.P.&0;'|
00000040 59 00 df 7d 00 00 00 1e 77 1d 56 c2 50 00 26 30 |Y..}....w.V.P.&0|
00000050 3b 27 59 00 df 7d 00 00 00 18 00 00 00 ff 00 4c |;'Y..}.........L|
00000060 44 32 53 30 30 30 30 30 30 30 30 31 00 00 00 fc |D2S000000001....|
00000070 00 4d 6f 74 6f 4c 44 32 53 20 20 20 20 20 01 4a |.MotoLD2S .J|
00000080 02 03 14 70 41 02 23 09 02 01 83 01 00 00 65 03 |...pA.#.......e.|
00000090 0c 00 10 00 20 1c 56 c2 50 00 26 30 3b 27 59 00 |.... .V.P.&0;'Y.|
000000a0 df 7d 00 00 00 1e 7e 1d 56 c2 50 00 26 30 3b 27 |.}....~.V.P.&0;'|
000000b0 59 00 df 7d 00 00 00 1e 20 1c 56 c2 50 00 26 30 |Y..}.... .V.P.&0|
000000c0 3b 27 59 00 df 7d 00 00 00 1e 20 1c 56 c2 50 00 |;'Y..}.... .V.P.|
000000d0 26 30 3b 27 59 00 df 7d 00 00 00 1e 20 1c 56 c2 |&0;'Y..}.... .V.|
000000e0 50 00 26 30 3b 27 59 00 df 7d 00 00 00 1e 00 00 |P.&0;'Y..}......|
000000f0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 b3 |................|

Here's a partial dump:

Detailed Timing Descriptor 1
Pixel Clock: 72MHz
Horizontal Active: 1366
Horizontal Blanking: 194
Vertical Active: 768
Vertical Blanking: 38
Horizontal Sync Offset: 59
Horizontal Sync Pulse: 39
Vertical Sync Offset: 5
Vertical Sync Pulse: 9
Horizontal Display Size: 223
Vertical Display Size: 125
Horizontal Border: 0
Vertical Border: 0
Interlaced: false
Stereo Mode: 0
Sync Type: 3

The Lapdock 100 works fine on the Raspberry Pi, but the Lapdock 500 does not. After some googling I found this thread:

viewtopic.php?f=28&t=5875&p=1312786#p1312786

So apparently the Raspberry Pi rejects video modes which have even a slightly nonstandard pixel clock.

I tried changing the EDID info using i2cset:

i2cset -y (I2C bus) 0x50 0x36 0x20
i2cset -y (I2C bus) 0x50 0c37 0x1c
i2cset -y (I2C bus) 0x50 0xff 0xee

However, the EDID EEPROM is write-protected and I was not able to change the EDID info.

So it looks the only way to get the Lapdock 500 working properly without HDMI overrides is by modifying the kernel. It should work anyway because my Lapdock 500 works fine on both x86 Ubuntu and Windows 10 without any software kludges.

jaarochafree
Posts: 1
Joined: Thu Nov 29, 2018 5:32 am

Re: problems setting raspberry pi up with lapdock 500

Thu Nov 29, 2018 5:39 am

Greetings, searching and searching the internet I have seen the possibility of using the Motorola lapdock second screen Chinese. so I bought a 100, since I saw that it is the simplest of use. But I've always liked the 500, for having more features (reader, camera, etc). But I want to use it with phones, not with Raspberry Pi, you can refer me to a post about This theme, the "lapdock 500, with cellular cell phones. "Thank you

Jamesbeat
Posts: 47
Joined: Mon Oct 15, 2012 8:19 pm

Re: problems setting raspberry pi up with lapdock 500

Thu Jan 03, 2019 10:50 pm

I'm considering buying a Lapdock 500, and I think I understand how to get it working.

I have a question about the circuit diagram though - it looks to me like Vcc is not connected to the Pi, and thus the Pi would not be powered by the Lapdock battery.

Is this correct, or am I missing something?

What is the reason for Vcc not being connected? Is it possible to connect Vcc so that it can power the Pi?

I would like to know before spending any money, because if the Pi would need a separate power supply, that would kill the deal for me.

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