MediaCow Touch 2 - LattePanda Mu Tablet
CTCL 2024-10-01 07:22:39 242 Views0 Replies Background
MediaCow Touch 2 has been a project that I have intermittently worked on since March 2021 after the successful MediaCow Touch project in 2020. The MediaCow series itself dates back to October 2018. I have had interest in electrical engineering and computer science in general since a young age though most of my experience has been from the last four years.
In May 2024, I have signed up for the LattePanda Mu Free Trial Event. The project idea was accepted in June 2024 and development of the new version of the device commenced on June 24, 2024. Prior to this, the project idea surrounded the use of a System on Module that used a Rockchip RK3399 ARM SoC.
The LattePanda Mu seems perfect for my project as its Intel Processor N100 SoC is intended for portable PC-like devices such as laptops, Chromebooks and tablets. The use of an x86-64 CPU allows for a more familiar development environment along with PC-like performance.
MediaCow Touch 2 makes use of a custom-designed carrier board, 3D printed case, 11.6" eDP touchscreen and a laptop battery pack along with other parts.
Hardware
As part of the event, the project makes use of the LattePanda Mu System on Module.
The project uses a custom-designed carrier board that may be either a four-layer or six-layer design.
The following is just a summary of what I have planned and is still subject to change at any time so I recommend that one should look at the documentation of the project (link below) for updated information.
Embedded Controller
The embedded controller, referred to as "SMEC" in the context of the project, is used to control various devices on and off the carrier board.
Starting September 11, 2024, the project makes use of the Sunplus Technology/Tibbo Technology SP7021 System in Package. I have had interest in the SP7021 since 2020 and I thought this project would be a good use of it. Prior to the SP7021, an STMicroelectronics STM32L496 microcontroller was used as the embedded controller.
The idea to use the SP7021 came after I decided to add a side-mounted display and keypad for device configuration independent of the system (LattePanda Mu). The display chosen required to be interfaced over a parallel TTL interface.
I knew this was an incredibly ambitious addition to an already ambitious project but the learning experience that I could get out of it and already have gotten out of it is more than valuable.
Battery and Power Subsystem
Battery and power management has been the main difficulty since the first MediaCow idea in late 2018.
MediaCow Touch 2 uses an off-the-shelf battery pack intended as a replacement for a HP FM08 battery pack. The battery pack uses a 4S2P configuration that defines a voltage range of 12-16.8 volts.
Type-C Power Delivery
Like some laptops, MediaCow Touch 2 accepts up to 20v on both USB Type-C ports for charging and system power.
A feature unique to MediaCow Touch 2 is that it can also source up to 20v through the USB Type-C ports while on battery or plugged in.
Internal Power Management
MediaCow Touch 2 makes use of many power management ICs. In regulator selection, an input voltage range of 12-20v must be considered.
Internal Connectivity
The carrier board design makes use of all nine HSIO interfaces. The first two, HSIO 0 and HSIO 1 are used for USB 3.2 that are connected to the USB Type-C ports. HSIO 2 is used for the internal M.2 Key E slot intended for use with Wi-Fi/Bluetooth modules. HSIO 3 is used for the one Intel I210 gigabit Ethernet controller. HSIO 6 is used for the internal M.2 Key B slot for an optional WWAN module. HSIO 8, 9, 10 and 11 are used for the M.2 Key M slot for the internal SSD.
M.2 Key E
M.2 Key E is mainly intended for the addition of a Wi-Fi/Bluetooth module. This allows for Wi-Fi and Bluetooth to be disabled completely by removing the module.
M.2 Key B
M.2 Key B was a recent consideration. It is intended for use with WWAN/Cellular modules. A SIM card slot is available for tis purpose.
M.2 Key M
M.2 Key M is mainly intended for use with an internal SSD. There would be mounting points for SSD sizes of 2230, 2242 and 2280.
External Connectivity
On the right side, these connectors are present:
- 2x USB Type-C with USB 3.2 and PD support
- 2x USB 3 Type-A
- 2x USB 2 Type-A
- HDMI
- Gigabit Ethernet
Display
After a week of research at the beginning of development in June 2024, I eventually decided to use the 11.6" eDP touchscreen from DFRobot intended for use with the LattePanda Mu. It was the lowest cost option for a display of that size and resolution and it was already tested with the LattePanda Mu specifically.
Progress
Due to multiple factors, many of them personal, I have not gotten as much done as I wanted to.
What I have completed already is at the GitHub repository: https://github.com/ctcl-bregis/
Full documentation of the project can be found here: https://ctcl.lgbt/projects/mct2/
On September 28, 2024, I decided to halt all development on hardware projects until I finish work related to college and critical software projects. After I finish needed work, I may continue development of MediaCow Touch 2.
