BOM

[rfuest]

Continued from embedded-graphics/embedded-graphics#671:

Sorry if I wasn't clear earlier in the thread; I think your list of 4 displays is a good one:

• SSD1306 OLED (1 BPP)
• SSD1327 OLED (4 BPP)
• ILI9341 LCD (16 BPP or 18 BPP)
• A three color EPD

As for specifics (as close to those as you can get on Aliexpress...):

• SSD1306: Any I2C 0.96" OLED module, e.g. https://www.aliexpress.com/item/32638662748.html (any colour)
• SSD1327: I don't have much experience with these modules but this looks like a common form factor for the modules. Shall we go with the I2C one? We can jumper between this and the SSD1306.
• ILI9341: this module is the most common form factor and supports SPI.
• EPD: The 2.13" and 2.9" modules here look like a common form factor. The connectors appear the same, so making a layout to accept both sizes with two sets of mounting holes would be easy enough.

[rfuest]

I picked a semi random store on AliExpress and tried to find all displays there:

• SSD1306: https://www.aliexpress.com/item/32896205376.html, 0.96 4pin white black, 1.84€
• SSD1327: https://www.aliexpress.com/item/4000080365758.html, White, 8.35€
• ILI9341: https://www.aliexpress.com/item/4000219159401.html, 2.8 TFT NO Touch, 9.46€
• Epaper: https://www.aliexpress.com/item/1005001344572194.html, Red, 15.35€

The prices include VAT and with shipping I would need to pay 37.53€.

[rfuest]

Or from this store, which actually might be the same company: https://greatzt.aliexpress.com/store/1916536
They have free shipping for orders above 35.90€, which means that the total would be less if I order some more components to reach that threshold. And I've actually used that shop in the past.

[jamwaffles]

Or from this store, which actually might be the same company

Looks good (although now I'm going to be browsing that site until 2am so thanks for that ;)). Let me know when you've ordered and we can arrange some funds. For the sake of consistency, if you could post the links here too I can order the exact same modules.

[rfuest]

These are the items I'm going to order:

• SSD1306: https://www.aliexpress.com/item/32896971385.html, white, 1.75€
• SSD1327: https://www.aliexpress.com/item/1005002883031119.html, white, 8.62€
• ILI9341: https://www.aliexpress.com/item/1005003152078101.html, 2.8 TFT, 8.61€
• Epaper: https://www.aliexpress.com/item/4001350149041.html, Red, 12.19€

Looks good (although now I'm going to be browsing that site until 2am so thanks for that ;)).

Sorry to hear that, but I'm also glad that I'm not the only person this has happened to 😉. Did you find anything that could be of interest to our project? I still need to spend another ~4€ to get free shipping.

[rfuest]

I'm thinking about adding a 1.3" 128x64 OLED to the order. The additional size would make it easier to see individual pixels.

There are two versions:

• One that is SH1106 based: https://www.aliexpress.com/item/32777866923.html
• And one that claims to be SSD1306 based: https://www.aliexpress.com/item/4000191763740.html
  But the schematic says that it is a SSD1315, which is also printed on the PCB. Do you know how compatible the SSD1306 and SSD1315 are?

For the OLED footprint on the PCB I would like to make it compatible with both the 0.96" and the 1.3" modules. This primarily means that we need to have enough room around the connector to fit an 1.3" module. But there is some inconsistency in the pinouts. The 1.3" modules and the 0.96" have swapped VCC and GND pins. There seems to be solder jumpers on the 1.3" module to swap the order of the VCC and GND pins, but to be sure I would like to also include jumpers on our PCB.

[jamwaffles]

Did you find anything that could be of interest to our project?

I didn't, although I was more browsing than looking for anything specific.

I'm thinking about adding a 1.3" 128x64 OLED to the order.

I'm familiar with the SH1106, and the contradicting driver ICs on the "claimed" one is suspicious. I don't know how compatible the SSD1315 is but considering there's already a driver for the SH1106 that seems like the better option.

For the OLED footprint on the PCB I would like to make it compatible with both the 0.96" and the 1.3" modules.

Sounds good, and jumpers for the swapped pins don't seem like too much of an issue, as long as we don't forget to change them when swapping displays.

[jamwaffles]

The 1.3" modules and the 0.96" have swapped VCC and GND pins.

I just remembered; the 0.96" SSD1306 and the SH1106 modules I have both use identical pinouts, so we might not even need jumpers as long as the modules haven't changed in the few years since I ordered them.

[rfuest]

I didn't, although I was more browsing than looking for anything specific.

One item caught my eye: https://www.aliexpress.com/item/4001118194342.html It's unfortunately not using a RISC-V ESP32, but it would be a cheap non ARM Arduino compatible board. Do you think that would be useful at all or should we start with ARM compatible boards (like a Nucleo) and care about other architectures later?

Sounds good, and jumpers for the swapped pins don't seem like too much of an issue, as long as we don't forget to change them when swapping displays.

That would indeed by bad. I still hope that we get the same pinout on all modules or at least can change some of them to match the others.

I just remembered; the 0.96" SSD1306 and the SH1106 modules I have both use identical pinouts, so we might not even need jumpers as long as the modules haven't changed in the few years since I ordered them.

Judging by the images on AliExpress and the banner image in SH1106 crate repo they have changed. But you never know what you get.

[jamwaffles]

Do you think that would be useful at all or should we start with ARM compatible boards (like a Nucleo) and care about other architectures later?

Let's start with ARM. I'm sure we'll start seeing RISC-V ESP-32 Arduino compatibles soon so I think we just need to wait.

Judging by the images on AliExpress and the banner image in SH1106 crate repo they have changed. But you never know what you get.

Typical, yeah who knows what will end up coming through the post. Hopefully not some kind of hair care product the homepage keeps advertising to me...

[rfuest]

Typical, yeah who knows what will end up coming through the post. Hopefully not some kind of hair care product the homepage keeps advertising to me...

Let's hope so. Hair care products aren't the worst things I've got recommended by AliExpress. but let's no go into details here.

If you don't have any more changes we should make, I'll order these items today:

• SH1106: https://www.aliexpress.com/item/32777866923.html, white, 3.09€
• SSD1327: https://www.aliexpress.com/item/1005002883031119.html, white, 8.72€
• ILI9341: https://www.aliexpress.com/item/1005003152078101.html, 2.8 TFT, 8.71€
• Epaper: https://www.aliexpress.com/item/4001350149041.html, Red, 12.33€

[jamwaffles]

but let's no go into details here.

Absolutely :D

That list looks good, feel free to make the order. I'll follow suit soonish. Throw me an email or a message on Matrix and we can sort funds out (or we can wait until you've got some devboards too).

[rfuest]

That list looks good, feel free to make the order. I'll follow suit soonish. Throw me an email or a message on Matrix and we can sort funds out (or we can wait until you've got some devboards too).

OK. I'll wait until we have ordered everything.

[rfuest]

Just a quick update to let you know that my display order has arrived today. All displays arrived in one piece and the larger displays were even packaged in plastic cases. I didn't have time to hook up the e-paper and TFT yet, but all I2C OLEDs did work. It took me a while to remember that we did choose a SH1106 based OLED and not a SSD1306 based one, but other than that it was pretty painless to get the displays working.