Here is my latest (and most likely final) all-in-one portable transport enclosure for the Mojo: the "MojoPi".
Size comparison with iPhone 6s
It consists of:
Raspberry Pi 3 Mainboard with built-in WiFi, but with the LAN, USB, HDMI, and audio ports removed.
Waveshare Spotpear 3.5" Resistive Touch Screen or equivalent (see
http://www.ebay.com/itm/291722114342?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT)
Adafruit 2500 mAh Lithium battery to power the RPi3 (at least 3hrs play time)
Adafruit Powerboost 1000c (to convert the 2500 mAh 3.7 volt battery to 5 volts and to charge the battery)
Anker USB Dual SD/MicroSD reader removed from shell
SD to Micro SD FPC Extender
2 PNY 512GB SD cards
200GB Sandisk MicroSD card (OS + Music) inserted in RPi3 microSD card slot
Adafruit Switch
Chord Mojo
3D Print Enclosure
Its dimensions are 125mm long x 98.2mm wide x 26mm high and it weighs 358g. The Mojo is connected to the RPi3 via a DIY microUSB cable soldered directly to the RPi3. The dual USB SD/MicroSD card reader is also soldered directly to the RPi3. The MojoPi can hold up to 1.2 TB of music on 2 full-size SD cards and a 200 GB microSD card. The interface is Rune Audio (based on Arch Linux). I can access Rune Audio through the screen or remotely via WiFi on a web browser using the IP address of the MojoPi.
The touchscreen is resistive, not capacitive, and so requires a fingernail or a stylus; it is not very easy to scroll. There doesn't seem to be a readily-available 3.5" or smaller capacitive touch screen that works with both the RPi3 and Rune Audio.
I need to insert a USB 2.0 Micro-B Male to Micro-AB Female Adapter into a slot on the side to charge the Mojo.
I think this is as small an enclosure as possible that contains both a 3.5" screen and a Mojo without removing the Mojo board from its case and connecting the Mojo directly to the RPi instead of using the Mojo's microUSB port. That would potentially narrow the unit by about 10 mm. A smaller board (One example is the Odroid C0), containing just a SOC for the operating system, an on-board battery booster/charger, and USB connections to SD cards, could provide for either more storage or a larger battery, but wouldn't change the overall size very much, since the Mojo and the screen pretty much determine the minimum dimensions of the enclosure. The plastic enclosure is fairly sturdy, but a harder plastic or metal enclosure would clearly be preferable.
I haven't done any kind of real comparison between the MojoPi and a more traditional phone/Mojo or PC/Mojo setup, but to me it sounds great. Despite the slapdash internal wiring, I haven't had any noticeable clicks or interference. I've played 44.1/16 up to 192/24 PCM without any problem. DSD64 seems to work well enough, although I have had the occasional drop-out.
Is it just me or does anyone else think it would be cool if Chord came out with something like this?
Cheers,
Rod