Pi Zero I2c Display not working.

[Beforeeverythingends]

Hi I recently made a minidexed for a friend using an old rpi 3b they had. That build went great. I used a 1602 display without i2c.

I liked it so much that I decided to buy a Pi Zero 2W and make one for myself. I haven't wired up an encoder or the DAC yet but I can't get the I2c 1602 display to work.

It's not a contrast issue, the display does light up and show the white boxes. And the contrast adjustment on the I2c board works.

I've changed the I2c address in the .ini file to 0x27 as per the instructions.

Is there anything I'm missing?

Though I'm not new to electronics in general I am very new to micro controllers. Was there something I was supposed to do with the pi Zero before installing mini dexed on the memory card?

Also just to rule out hardware faults I've used 3 memory cards and 2 displays.

Any help would be greatly appreciated. Thank you.

[probonopd]

Hi @Beforeeverythingends are you sure you have connected all wires correctly between the display and the Pi? Can you maybe take a picture showing how you wired things up?

[Beforeeverythingends]

Ok so I installed an image of raspberry pi os and still get no signal. I think it's a faulty zero. Unless you all have any information in unaware of.

Thanks

[diyelectromusic]

So you're getting no display at all on the Zero with a stock RPi OS and nothing on the GPIO pins?

If that's the case, I guess yes, you need to work out how to get the Pi working itself first following a standard Pi trouble shooting tutorial - things like power supply, proper connections, SD card issues, and so on.

Do you have a multimeter? Are you seeing a good 3V3 and 5V on the GPIO for example? I seem to recall there are some test points on a zero too...

MiniDexed will start printing to a HDMI display as soon as it powers up with no config changes required - assuming the files can be read on boot at all.

Kevin

[Beforeeverythingends]

Hi thanks for the reply. Nothing showed up on the hdmi at all. Screen would just show no signal.

I tested the voltages on the pins right after the first time I connected the screen and it didn't work. They all seemed fine.

I've contacted pimoroni and I'll be returning this board and getting a replacement.

I appreciate all the help you've given. Hopefully the new one works fine. I'll update the thread when I get it and try again.

Thanks.

[probonopd]

Well, can you boot Raspberry Pi OS on this board?

[Beforeeverythingends]

Not received the new one yet. Raspberry pi os wouldn't boot on this one.

[Beforeeverythingends]

New one came. Everything seems to be working so far.

Had a bit of confusion when it booted raspberry pi os but mini dexed wouldn't.

Turned out that when I reformatted the SD card to install mini dexed the default file system was exfat.

Changed it to fat32 and it booted mini dexed fine. I2c Display works both the LCD and the oled.

Thanks for all the help.

[Beforeeverythingends]

Got round to finishing the build tonight. Thanks for all the help and for this amazing project.