Mobile device build around existing chassis - Page 1
Forum section: electronics / projects

author: PhoneMaker57
author_rank: Newbie
timestamp: May 01, 2024, 01:28:42 am
content: I am a muppet and I decided I’m gonna make a phone. The experience so far has been defined by the number of brick walls I’ve had to break through, and the current problem is the display.For some stupid reason, the phone has to be built into the chassis of a blackberry priv (I’ll explain if anyone asks), which has a flat area of approx 60mm x 128mm, and including the curved bevel on the frame, about 68mm x 128mm, this is ignoring the issue of either slotting the cable through a designated hole in the middle of the frame, or tearing it a new one as required.In order of preference, I have 3 options:1)https://www.waveshare.com/6inch-hdmi-amoled.htmthis thing from waveshare. Unfortunately discontinued, but according to a little sleuthing, it’s a BOE BO599FF2KM for anyone who wants to look up the datasheets (if that’s true, it was a bit cheeky of waveshare to warn about counterfeit waveshare items)2) the oem AMB543DY02 panel. According to more sleuthing and the priv that I sacrificed on the alter of my hubris, the blackberry priv uses this panel. Apparently the vivo xplay 5, moto droid 2, moto x force, and very possibly, iPhone 12 mini all use similar flexible 5.43” 16:9 panels too. Very annoying because I can’t find out the brand or data sheets, but I can provide photos of the connectors (the logo is a U looking thing), I also recorded all the text I could find on anything directly attached to the display on the priv3) a non flexible display that sits neatly underneath the oem glass panel. Recommendations appreciated to get me as close to that 60 x 128 limitAnyways, the reason I’m asking is because none of the options are at all great.The BOE panel seems to be EOL, so harder to find, and when I have found displays available for single/sample orders, they’ve been very expensive, equaling the cost of every other part in this infernal project put together. Also, I could only find a partial copy of the data sheet, so I was unclear on the max power draw for my estimationsAs much as I’d love to use the OEM display, I know more than enough code to know that I don’t know enough code to be reverse engineering drivers (not to mention, there’s a whole extra layer of science that I know I know even less of). Acquiring any of the compatible panels wouldn’t be too bad I don’t think, like they seem to be anywhere between £50 and £80, which is fine, but they ship sans controller board (not that you can just buy one anyway), and I’m really not sure I’ll be able to get them working off a raspberry pi mipi dsi out.Obviously option 3 is cheaper and easier, but the priv already had a bevel which admittedly only looks thick to me because I’m used to newer devices, and part of this project is trying to get this phone to look ever so slightly less like a contraption, and more like an actual device a human being might useEither way, the info I’m after:1) does it look like I could run the BOE panel directly off the rpi’s mipi? (Using a raspberry pi cm4 with nano carrier B from waveshare, so all 4 channels available) if so, what cables do I need?2) AMB543DY02 datasheets? Any other AMB543DYXX panel works3) from the datasheets, how do I work out wattage of the BOE panel? The stuff I could find on panox gave me a whole bunch of different voltages and amps. 5v in was easy enough to figure out, and the touch ic made sense, but I couldn’t work out if the different amps in were modes or pins. Also, is wattage what I want when I’m trying to find a battery to power this nonsense?4) I’ve been poring through panels for weeks now, but if anyone has anything I might have overlooked that fits the curved dimensions, amazing. The lower resolution the better too.5) if I truly was dense enough to try reverse engineering the oem panel, what would my process look like? Bear in mind, I have a master’s in high level coding (like game stuff), and a working memory that would make a goldfish look downright impressive, so I don’t have the head for electrical engineering in the same way (maybe the way it was taught, but programming principles made sense to me, where EE seemed more like needing to just know that if you do x and y you get z)6) any recommendations for a flat panel that fits the 60mm x 128mm size? I can scale down (or a few mm up) on the y axis, because I’m not doing a front facing, and I’m seating the earpiece in the main chassis. If so, does anyone know what my options would be for 5mm wide flexible display strips, and or additional e-inks to fill up left over space on the y axis? I’ve been toying with the idea of having a main display with maybe an eink clock/widget display/music player display underneath, and battery indicators/temperature sensors/go faster stripes down the side, a la the original priv.7) I was doing my battery calculations earlier, and it was truly dire. 5v 8a seems to work out to needing a 320Whbattery if I want to run it for 20 hours. Now, granted I’m not running this thing top whack for 20 hours. If I’m even awake for 20 hours, I think I’d need plugging into the battery myself. All that said, this factors in the rpi hq camera, and dac (fiio e10k) blasting for those 20 hours too, while also maxing out the cm4 and probably just having white pixels on the screen. Anyways, I’m convinced I went wrong somewhere, because that can’t be right when you’ve got people running a uconsole cm4 off two 18650s, and cranking out 8 hours somehow? Pls advise on how I should be doing these calculations, because somebody is missing a step, and this is a group project of 1, so I’m really not sure who to blame.how would I calculate the power draw of some of the components that don’t explicitly list them (without poking them with a multimeter or emailing customer services)? I’m currently thinking of using a waveshare sim7600-h 4g dongle (dongle format to allow PoE via the gpio while conserving space, and to get the audio playing through the dac into a custom audio circuit, rather than needing to loop it out of a hat’s 3.5mm jack), but short of the quectel sim 7600-h spec (I think 5v 2a off the top of my head? I can’t find much else, although it does look suspiciously like the pitalk 4g module. Main question is though, is that enough for an estimate, or do we reckon there’s a load of peculiar circuitry eating my watts?I appreciate this project is completely balmy, and my questions are very long form, but in my defence I’m trying to nail as much theory as I can before I start slapping money down for it, because a lot of these components are not cheap and cheerful (because some cretin decided this had to be built into a blackberry priv chassis), and ultimately, if all I can build is a device that barely functions, and runs for maybe an hour or two, I might start having to make more compromises.