Flip Screen of SSD1306

Question

Flip Screen of SSD1306

ppontre opened this issue 6 years ago · comments

Hi Peter,
I can't sort out how to flip screen on Micropython ESP32 using the library.
I've got a TTGO board with ESP, Battery, SSD1306.
I need to flip the screen upside down
Any suggestion ?
Thanx in advance
Paolo

Peter Hinch · Answer 1 · Thu Feb 15 2018 15:06:11 GMT+0800 (China Standard Time)

Hi Paolo,
it can be done but it would be a substantial rewrite. I can't see a simple way to fix _printchar() but a rewritten _printchar_bitwise() function could invert each character. The _newline() method would need adapting so that text flow was reversed.
Pete

ppontre · Answer 2 · Thu Feb 15 2018 20:44:50 GMT+0800 (China Standard Time)

Thanx Pteter for yr prompt answer. Here’s my update: 1. There’s some trick, consisting in 2 commands: flip (vert) and mirro (horiz) the entire display. After these commands, no other change is required. Unfortunately i could not succeed in finding and issuing the command 1. It seems there’s a trade-off between beautiful fonts and flip feature: yuou can’t have both. I succeeded in flipping a display arranged with a 8x8 font, no auto-cr, all-manual…. 1. This evening i’ll have another trial Regairds Paolo Inviato da Posta<https://go.microsoft.com/fwlink/?LinkId=550986> per Windows 10 Da: Peter Hinch<mailto:notifications@github.com> Inviato: giovedì 15 febbraio 2018 08:06 A: peterhinch/micropython-samples<mailto:micropython-samples@noreply.github.com> Cc: ppontre<mailto:ppontre@hotmail.com>; Author<mailto:author@noreply.github.com> Oggetto: Re: [peterhinch/micropython-samples] Flip Screen of SSD1306 (#3) Hi Paolo, it can be done but it would be a substantial rewrite. I can't see a simple way to fix _printchar() but a rewritten _printchar_bitwise() function could invert each character. The _newline() method would need adapting so that text flow was reversed. Pete — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub<#3 (comment)>, or mute the thread<https://github.com/notifications/unsubscribe-auth/AADUzOBvJCBgIrJJjC6hD547g9l1-ns3ks5tU9dkgaJpZM4SF8oo>.

RobH · Answer 3 · Thu Aug 02 2018 17:06:24 GMT+0800 (China Standard Time)

@paolo

I succeeded in flipping a display arranged with a 8x8 font, no auto-cr, all-manual…. 1. This evening i’ll have another trial

Hi Paolo, would you be so kind to publish your fix?
Besides an SSD1306 I'm also using an SH1106 for which the driver has a rotate method builtin, which serves my needs. I would like a similar solution for a SSD1306 display just as your described here.
Regards, Rob.

Peter Hinch · Answer 4 · Wed Aug 15 2018 01:09:10 GMT+0800 (China Standard Time)

@ppontre @robhamerling You may like to look at this update: the CWriter class supports upside down display on any device whose driver is subclassed from frmebuf (e.g. SSD1306).

RobH · Answer 5 · Wed Aug 15 2018 01:51:03 GMT+0800 (China Standard Time)

@peterhinch Thanks for this pointer, looks very nice. However currently I'm satisfied with the fixed 8x8 font and needed only flipping. Maybe useful for a new project.
BTW: In the meantime I found how to perform flipping by modifying a few bits in ssd1306 registers. I opened an issue (#4015) at github.com/micropython and suggested a solution.

Peter Hinch · Answer 6 · Wed Aug 15 2018 15:41:51 GMT+0800 (China Standard Time)

My update aims for generality by supporting any display whose driver is subclassed from framebuf.

Alas inverting the display means using the CWriter class. This is over an order of magnitude slower than Writer as it renders glyphs one pixel at a time rather than via bit blitting.

Your SSD1306-specific method evidently won't carry that speed penalty. It also has the advantage that the same coordinates apply to graphics and text, whereas mine only flips text.